Java junit tutorial

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JUNIT TUTORIAL
Simply Easy Learning by tutorialspoint.com
tutorialspoint.com

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ABOUT THE TUTORIAL
JUnit Tutorial
JUnit is a unit testing framework for the Java programming language. JUnit has been important in the development of test-
driven development, and is one of a family of unit testing frameworks collectively known as xUnit that originated with JUnit.
This tutorial will teach you how to use JUnit in your day-2-day life of any project unit testing while working with Java
programming language.
Audience
This tutorial has been prepared for the beginners to help them understand basic functionality of JUnit tool. After completing
this tutorial you will find yourself at a moderate level of expertise in using JUnit testing framework from where you can take
yourself to next levels.
Prerequisites
We assume you are going to use JUnit to handle all levels of Java projects development. So it will be good if you have
knowledge of software development using any programming language specially Java programming and software testing
process.
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Table of Contents
JUnit Tutorial............................................................................. i
Audience................................................................................... i
Prerequisites ............................................................................. i
Copyright & Disclaimer Notice................................................... i
JUnit Overview...........................................................................
What is JUnit ?...............................................................................................
Features........................................................................................................
What is a Unit Test Case ? ...............................................................................
JUnit Environment Setup............................................................
System Requirement ......................................................................................
Step 1 - verify Java installation in your machine.................................................
Step 2: Set JAVA environment .........................................................................
Step 3: Download Junit archive........................................................................
Step 4: Set JUnit environment .........................................................................
Step 5: Set CLASSPATH variable .......................................................................
Step 6: Test JUnit Setup ..................................................................................
Step 7: Verify the Result..................................................................................
JUnit Test Framework ................................................................
Features........................................................................................................
Fixtures .........................................................................................................
Test suite.......................................................................................................
Test runner....................................................................................................
JUnit classes ..................................................................................................
JUnit Basic Usage......................................................................
Create a Class ................................................................................................
Create Test Case Class ....................................................................................
Create Test Runner Class.................................................................................
JUnit API....................................................................................
Assert Class ...................................................................................................
TestCase Class................................................................................................
TestResult Class .............................................................................................
TestSuite Class ...............................................................................................

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JUnit Writing Tests .....................................................................
JUnit Using Assertion.................................................................
Annotation ....................................................................................................
JUnit Execution Procedure.........................................................
JUnit Executing Tests.................................................................
Create a Class ................................................................................................
JUnit Test Suite..........................................................................
Create a Class ................................................................................................
Create Test Case Classes .................................................................................
Create Test Suite Class....................................................................................
JUnit Ignore Test........................................................................
Create a Class ................................................................................................
JUnit Time Test..........................................................................
Create a Class ................................................................................................
JUnit Exception Test ..................................................................
Create a Class ................................................................................................
JUnit Parameterized Test...........................................................
Create a Class ................................................................................................
Create Parameterized Test Case Class ..............................................................
JUnit Plug with ANT ...................................................................
Step 1: Download Apache Ant .........................................................................
Step 2: Set Ant Environment............................................................................
Step 3: Download Junit Archive .......................................................................
Step 4: Create Project Structure.......................................................................
Create ANT Build.xml......................................................................................
JUnit Plug with Eclipse...............................................................
Step 1: Download Junit archive........................................................................
Step 2: Set Eclipse environment.......................................................................
Step 3: Verify Junit installation in Eclipse ..........................................................

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JUnit Extensions ........................................................................
Cactus...........................................................................................................
JWebUnit ......................................................................................................
XMLUnit........................................................................................................
MockObject...................................................................................................

TUTORIALS POINT
Simply Easy Learning
JUnit Overview
Testing is the process of checking the functionality of the application whether it is working
as per requirements and to ensure that at developer level, unit testing comes into picture.
Unit testing is the testing of single entity (class or method). Unit testing is very essential to every
software company to give a quality product to their customers.
Unit testing can be done in two ways
Manual testing Automated testing
Executing the test cases manually without any
tool support is known as manual testing.
 Time consuming and tedious: Since test cases
are executed by human resources so it is very
slow and tedious.
 Huge investment in human resources: As test
cases need to be executed manually so more
testers are required in manual testing.
 Less reliable: Manual testing is less reliable as
tests may not be performed with precision each
time because of human errors.
 Non-programmable: No programming can be
done to write sophisticated tests which fetch
hidden information.
Taking tool support and executing the test
cases by using automation tool is known as
automation testing.
 Fast Automation runs test cases significantly
faster than human resources.
 Less investment in human resources:Test
cases are executed by using automation tool so
less tester are required in automation testing.
 More reliable: Automation tests perform
precisely same operation each time they are
run.
 Programmable: Testers can program
sophisticated tests to bring out hidden
information.
What is JUnit ?
JUnit is a unit testing framework for the Java Programming Language. It is important in the test
driven development, and is one of a family of unit testing frameworks collectively known as xUnit.
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JUnit promotes the idea of "first testing then coding", which emphasis on setting up the test data for
a piece of code which can be tested first and then can be implemented. This approach is like "test a
little, code a little, test a little, code a little..." which increases programmer productivity and stability
of program code that reduces programmer stress and the time spent on debugging.
Features
 JUnit is an open source framework which is used for writing & running tests.
 Provides Annotation to identify the test methods.
 Provides Assertions for testing expected results.
 Provides Test runners for running tests.
 JUnit tests allow you to write code faster which increasing quality
 JUnit is elegantly simple. It is less complex & takes less time.
 JUnit tests can be run automatically and they check their own results and provide
immediate feedback. There's no need to manually comb through a report of test results.
 JUnit tests can be organized into test suites containing test cases and even other test
suites.
 Junit shows test progress in a bar that is green if test is going fine and it turns red when a
test fails.
What is a Unit Test Case ?
A Unit Test Case is a part of code which ensures that the another part of code (method) works as
expected. To achieve those desired results quickly, test framework is required .JUnit is perfect unit
test framework for java programming language.
A formal written test-case is characterized by a known input and by an expected output, which is
worked out before the test is executed. The known input should test a precondition and the
expected output should test a post condition.
There must be at least two test cases for each requirement: one positive test and one negative test.
If a requirement has sub-requirements, each sub-requirement must have at least two test cases as
positive and negative.

TUTORIALS POINT
JUnit Environment Setup
JUnit is a framework for Java, so the very first requirement is to have JDK installed in your
machine.
System Requirement
JDK 1.5 or above.
Memory no minimum requirement.
Disk Space no minimum requirement.
Operating System no minimum requirement.
Step 1 - verify Java installation in your machine
Now open console and execute the following java command.
OS Task Command
Windows Open Command Console c:> java -version
Linux Open Command Terminal $ java -version
Mac Open Terminal machine:~ joseph$ java -version
Let's verify the output for all the operating systems:
OS Output
Windows
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b07)
Java HotSpot(TM) Client VM (build 17.0-b17, mixed mode, sharing)
Linux
Java HotSpot(TM) Client VM (build 17.0-b17, mixed mode, sharing)
Mac
Java HotSpot(TM)64-Bit Server VM (build 17.0-b17, mixed mode,
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sharing)
If you do not have Java installed, install the Java Software Development Kit (SDK)
fromhttp://www.oracle.com/technetwork/java/javase/downloads/index.html. We are assuming
Java 1.6.0_21 as installed version for this tutorial.
Step 2: Set JAVA environment
Set the JAVA_HOME environment variable to point to the base directory location where Java is
installed on your machine. For example
OS Output
Windows
Set the environment variable JAVA_HOME to C:Program
FilesJavajdk1.6.0_21
Linux export JAVA_HOME=/usr/local/java-current
Mac export JAVA_HOME=/Library/Java/Home
Append Java compiler location to System Path.
OS Output
Windows
Append the string ;C:Program FilesJavajdk1.6.0_21bin to the
end of the system variable, Path.
Linux export PATH=$PATH:$JAVA_HOME/bin/
Mac not required
Verify Java Installation using java -version command explained above.
Step 3: Download Junit archive
Download latest version of JUnit jar file from http://www.junit.org. At the time of writing this
tutorial, I downloaded Junit-4.10.jar and copied it into C:>JUnit folder.
OS Archive name
Windows junit4.10.jar
Linux junit4.10.jar
Mac junit4.10.jar
Step 4: Set JUnit environment
Set the JUNIT_HOME environment variable to point to the base directory location where JUNIT
jar is stored on your machine. Assuming, we've stored junit4.10.jar in JUNIT folder on various
Operating Systems as follows.
OS Output
Windows Set the environment variable JUNIT_HOME to C:JUNIT
Linux export JUNIT_HOME=/usr/local/JUNIT
Mac export JUNIT_HOME=/Library/JUNIT

TUTORIALS POINT
Step 5: Set CLASSPATH variable
Set the CLASSPATH environment variable to point to the JUNIT jar location. Assuming, we've
stored junit4.10.jar in JUNIT folder on various Operating Systems as follows.
OS Output
Windows
Set the environment variable CLASSPATH to
%CLASSPATH%;%JUNIT_HOME%junit4.10.jar;.;
Linux export CLASSPATH=$CLASSPATH:$JUNIT_HOME/junit4.10.jar:.
Mac export CLASSPATH=$CLASSPATH:$JUNIT_HOME/junit4.10.jar:.
Step 6: Test JUnit Setup
Create a java class file name TestJunit in C: > JUNIT_WORKSPACE
import org.junit.Test;
import static org.junit.Assert.assertEquals;
public class TestJunit {
@Test
public void testAdd() {
String str= "Junit is working fine";
assertEquals("Junit is working fine",str);
}
}
Create a java class file name TestRunner in C: > JUNIT_WORKSPACE to execute Test
case(s)
import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;
public class TestRunner {
public static void main(String[] args) {
Result result = JUnitCore.runClasses(TestJunit.class);
for (Failure failure : result.getFailures()) {
System.out.println(failure.toString());
}
System.out.println(result.wasSuccessful());
}
}
Step 7: Verify the Result
Compile the classes using javac compiler as follows
C:JUNIT_WORKSPACE>javac TestJunit.java TestRunner.java
Now run the Test Runner to see the result
C:JUNIT_WORKSPACE>java TestRunner
Verify the output.
true

TUTORIALS POINT
JUnit Test Framework
JUnit is a Regression Testing Framework used by developers to implement unit testing in
Java and accelerate programming speed and increase the quality of code. JUnit Framework can be
easily integrated with either of the followings:
 Eclipse
 Ant
 Maven
Features
JUnit test framework provides following important features
 Fixtures
 Test suites
 Test runners
 JUnit classes
Fixtures
Fixtures is a fixed state of a set of objects used as a baseline for running tests. The purpose of a
test fixture is to ensure that there is a well known and fixed environment in which tests are run so
that results are repeatable. It includes
 setUp() method which runs before every test invocation.
 tearDown() method which runs after every test method.
Let's check one example:
import junit.framework.*;
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public class JavaTest extends TestCase {
protected int value1, value2;
// assigning the values
protected void setUp(){
value1=3;
value2=3;
}
// test method to add two values
public void testAdd(){
double result= value1 + value2;
assertTrue(result == 6);
}
}
Test suite
Test suite means bundle a few unit test cases and run it together. In JUnit, both @RunWith and
@Suite annotation are used to run the suite test. Here is an example which uses TestJunit1 &
TestJunit2 test classes.
import org.junit.runner.RunWith;
import org.junit.runners.Suite;
//JUnit Suite Test
@RunWith(Suite.class)
@Suite.SuiteClasses({
TestJunit1.class ,TestJunit2.class
})
public class JunitTestSuite {
}
import org.junit.Ignore;
public class TestJunit1 {
String message = "Robert";
MessageUtil messageUtil = new MessageUtil(message);
@Test
public void testPrintMessage() {
System.out.println("Inside testPrintMessage()");
assertEquals(message, messageUtil.printMessage());
}
}
@Test
public void testSalutationMessage() {
System.out.println("Inside testSalutationMessage()");
message = "Hi!" + "Robert";
assertEquals(message,messageUtil.salutationMessage());
}
}

TUTORIALS POINT
Test runner
Test runner is used for executing the test cases. Here is an example which assumes TestJunit test
class already exists.
}
}
}
JUnit classes
JUnit classes are important classes which is used in writing and testing JUnits. Some of the
important classes are
 Assert which contain a set of assert methods.
 TestCase which contain a test case defines the fixture to run multiple tests.
 TestResult which contain methods to collect the results of executing a test case.

TUTORIALS POINT
JUnit Basic Usage
Now we'll show you a step by step process to get a kick start in JUnit using a basic
example.
Create a Class
 Create a java class to be tested say MessageUtil.java in C: > JUNIT_WORKSPACE
/*
* This class prints the given message on console.
*/
public class MessageUtil {
private String message;
//Constructor
//@param message to be printed
public MessageUtil(String message){
this.message = message;
}
// prints the message
public String printMessage(){
System.out.println(message);
return message;
}
}
Create Test Case Class
 Create a java test class say TestJunit.java.
 Add a test method testPrintMessage() to your test class.
 Add an Annotaion @Test to method testPrintMessage().
 Implement the test condition and check the condition using assertEquals API of Junit.
Create a java class file name TestJunit.java in C: > JUNIT_WORKSPACE
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String message = "Hello World";
@Test
assertEquals(message,messageUtil.printMessage());
}
}
Create Test Runner Class
 Create a TestRunner java class.
 Use runClasses method of JUnitCore class of JUnit to run test case of above created test
class
 Get the result of test cases run in Result Object
 Get failure(s) using getFailures() methods of Result object
 Get Success result using wasSuccessful() methods of Result object
Create a java class file name TestRunner.java in C: > JUNIT_WORKSPACE to execute Test
case(s)
}
}
}
Compile the MessageUtil, Test case and Test Runner classes using javac
C:JUNIT_WORKSPACE>javac MessageUtil TestJunit.java TestRunner.java
Now run the Test Runner which will run test case defined in provided Test Case class.
Verify the output.
Hello World
true

TUTORIALS POINT
Now update TestJunit in C: > JUNIT_WORKSPACE so that test fails. Change the message string.
@Test
message = "New Word";
}
}
Verify the output.
Hello World
testPrintMessage(TestJunit): expected:<[New Wor]d> but was:<[Hello Worl]d>
false

TUTORIALS POINT
JUnit API
The most important package in JUnit is junit.framework which contain all the core
classses. Some of the important class are:
Serial No Class Name Functionality
1 Assert A set of assert methods.
2 TestCase A test case defines the fixture to run multiple tests.
3 TestResult
A TestResult collects the results of executing a
test case.
4 TestSuite A TestSuite is a Composite of Tests.
Assert Class
Following is the declaration for org.junit.Assert class:
public class Assert extends java.lang.Object
This class provides a set of assertion methods useful for writing tests. Only failed assertions are
recorded. Some of the important methods of Assert class are:
S.N. Methods & Description
1
void assertEquals(boolean expected, boolean actual)
Check that two primitives/Objects are equal
2
void assertFalse(boolean condition)
Check that a condition is false
3
void assertNotNull(Object object)
Check that an object isn't null.
4
void assertNull(Object object)
Check that an object is null
5
void assertTrue(boolean condition)
Check that a condition is true.
6 void fail()
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Fails a test with no message.
Let's try to cover few of the above mentioned methods in an example. Create a java class file name
TestJunit1.java in C: > JUNIT_WORKSPACE
import static org.junit.Assert.*;
@Test
//test data
int num= 5;
String temp= null;
String str= "Junit is working fine";
//check for equality
assertEquals("Junit is working fine", str);
//check for false condition
assertFalse(num > 6);
//check for not null value
assertNotNull(str);
}
}
Next, let's create a java class file name TestRunner1.java in C: > JUNIT_WORKSPACE to
execute Test case(s)
public class TestRunner1 {
Result result = JUnitCore.runClasses(TestJunit1.class);
}
}
}
Compile the Test case and Test Runner classes using javac
C:JUNIT_WORKSPACE>javac TestJunit1.java TestRunner1.java
C:JUNIT_WORKSPACE>java TestRunner1
Verify the output.
true
TestCase Class
Following is the declaration for org.junit.TestCaset class:

TUTORIALS POINT
public abstract class TestCase extends Assert implements Test
A test case defines the fixture to run multiple tests. Some of the important methods
of TestCase class are
1
int countTestCases()
Counts the number of test cases executed by run(TestResult result).
2
TestResult createResult()
Creates a default TestResult object.
3
String getName()
Gets the name of a TestCase.
4
TestResult run()
A convenience method to run this test, collecting the results with a default TestResult object.
5
void run(TestResult result)
Runs the test case and collects the results in TestResult.
6
void setName(String name)
Sets the name of a TestCase.
7
void setUp()
Sets up the fixture, for example, open a network connection.
8
void tearDown()
Tears down the fixture, for example, close a network connection.
9
String toString()
Returns a string representation of the test case.
Let's try to cover few of the above mentioned methods in an example. Create a java class file name
TestJunit2.java in C: > JUNIT_WORKSPACE
import junit.framework.TestCase;
import org.junit.Before;
public class TestJunit2 extends TestCase {
protected double fValue1;
protected double fValue2;
@Before
public void setUp() {
fValue1= 2.0;
fValue2= 3.0;
}
@Test
//Count the number of test cases
System.out.println("No of Test Case = "+ this.countTestCases());
//test getName
String name= this.getName();
System.out.println("Test Case Name = "+ name);
//test setName

TUTORIALS POINT
this.setName("testNewAdd");
String newName= this.getName();
System.out.println("Updated Test Case Name = "+ newName);
}
//tearDown used to close the connection or clean up activities
public void tearDown( ) {
}
}
}
}
}
Verify the output.
No of Test Case = 1
Test Case Name = testAdd
Updated Test Case Name = testNewAdd
true
TestResult Class
Following is the declaration for org.junit.TestResult class:
public class TestResult extends Object
A TestResult collects the results of executing a test case. It is an instance of the Collecting
Parameter pattern. The test framework distinguishes between failures and errors. A failure is
anticipated and checked for with assertions. Errors are unanticipated problems like an
ArrayIndexOutOfBoundsException. Some of the important methods of TestResult class are:
1
void addError(Test test, Throwable t)
Adds an error to the list of errors.

TUTORIALS POINT
2
void addFailure(Test test, AssertionFailedError t)
Adds a failure to the list of failures.
3
void endTest(Test test)
Informs the result that a test was completed.
4
int errorCount()
Gets the number of detected errors.
5
Enumeration<TestFailure> errors()
Returns an Enumeration for the errors.
6
int failureCount()
Gets the number of detected failures.
7
void run(TestCase test)
Runs a TestCase.
8
int int runCount()
Gets the number of run tests.
9
void startTest(Test test)
Informs the result that a test will be started.
10
void stop()
Marks that the test run should stop.
Create a java class file name TestJunit3.java in C: > JUNIT_WORKSPACE
import junit.framework.AssertionFailedError;
import junit.framework.TestResult;
public class TestJunit3 extends TestResult {
// add the error
public synchronized void addError(Test test, Throwable t) {
super.addError((junit.framework.Test) test, t);
}
// add the failure
public synchronized void addFailure(Test test, AssertionFailedError t) {
super.addFailure((junit.framework.Test) test, t);
}
@Test
// add any test
}
// Marks that the test run should stop.
public synchronized void stop() {
//stop the test here
}
}

TUTORIALS POINT
}
}
}
Verify the output.
true
TestSuite Class
Following is the declaration for org.junit.TestSuite class:
public class TestSuite extends Object implements Test
A TestSuite is a Composite of Tests. It runs a collection of test cases. Some of the important
methods of TestSuite class are
1
void addTest(Test test)
Adds a test to the suite.
2
void addTestSuite(Class<? extends TestCase> testClass)
Adds the tests from the given class to the suite.
3
int countTestCases()
Counts the number of test cases that will be run by this test.
4
String getName()
Returns the name of the suite.
5
void run(TestResult result)
Runs the tests and collects their result in a TestResult.
6
void setName(String name)
Sets the name of the suite.
7
Test testAt(int index)
Returns the test at the given index.
8
int testCount()
Returns the number of tests in this suite.

TUTORIALS POINT
9
static Test warning(String message)
Returns a test which will fail and log a warning message.
Create a java class file name JunitTestSuite.java in C: > JUNIT_WORKSPACE to create Test
suite
import junit.framework.*;
public static void main(String[] a) {
// add the test's in the suite
TestSuite suite = new TestSuite(TestJunit1.class,
TestJunit2.class, TestJunit3.class );
TestResult result = new TestResult();
suite.run(result);
System.out.println("Number of test cases = " + result.runCount());
}
}
Compile the Test suite classes using javac
C:JUNIT_WORKSPACE>javac JunitTestSuite.java
Now run the Test Suite.
C:JUNIT_WORKSPACE>java JunitTestSuite
Verify the output.
No of Test Case = 1
Test Case Name = testAdd
Updated Test Case Name = testNewAdd
Number of test cases = 3

TUTORIALS POINT
JUnit Writing Tests
Here we will see one complete example of JUnit testing using POJO class, Business logic
class and a test class which will be run by test runner.
Create EmployeeDetails.java in C: > JUNIT_WORKSPACE which is a POJO class.
public class EmployeeDetails {
private String name;
private double monthlySalary;
private int age;
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}
/**
* @return the monthlySalary
*/
public double getMonthlySalary() {
return monthlySalary;
}
/**
* @param monthlySalary the monthlySalary to set
*/
public void setMonthlySalary(double monthlySalary) {
this.monthlySalary = monthlySalary;
}
/**
* @return the age
*/
public int getAge() {
return age;
}
/**
* @param age the age to set
*/
public void setAge(int age) {
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this.age = age;
}
}
EmployeeDetails class is used to
 get/set the value of employee's name.
 get/set the value of employee's monthly salary.
 get/set the value of employee's age.
Create a EmpBusinessLogic.java in C: > JUNIT_WORKSPACE which contains business logic
public class EmpBusinessLogic {
// Calculate the yearly salary of employee
public double calculateYearlySalary(EmployeeDetails employeeDetails){
double yearlySalary=0;
yearlySalary = employeeDetails.getMonthlySalary() * 12;
return yearlySalary;
}
// Calculate the appraisal amount of employee
public double calculateAppraisal(EmployeeDetails employeeDetails){
double appraisal=0;
if(employeeDetails.getMonthlySalary() < 10000){
appraisal = 500;
}else{
appraisal = 1000;
}
return appraisal;
}
}
EmpBusinessLogic class is used for calculating
 the yearly salary of employee.
 the appraisal amount of employee.
Create a TestEmployeeDetails.java in C: > JUNIT_WORKSPACE which contains test cases to
be tested
public class TestEmployeeDetails {
EmpBusinessLogic empBusinessLogic =new EmpBusinessLogic();
EmployeeDetails employee = new EmployeeDetails();
//test to check appraisal
@Test
public void testCalculateAppriasal() {
employee.setName("Rajeev");
employee.setAge(25);
employee.setMonthlySalary(8000);
double appraisal= empBusinessLogic.calculateAppraisal(employee);
assertEquals(500, appraisal, 0.0);
}
// test to check yearly salary

TUTORIALS POINT
@Test
public void testCalculateYearlySalary() {
employee.setName("Rajeev");
employee.setAge(25);
employee.setMonthlySalary(8000);
double salary= empBusinessLogic.calculateYearlySalary(employee);
assertEquals(96000, salary, 0.0);
}
}
TestEmployeeDetails class is used for testing the methods of EmpBusinessLogic class. It
 tests the yearly salary of the employee.
 tests the appraisal amount of the employee.
Next, let's create a java class file name TestRunner.java in C: > JUNIT_WORKSPACE to
Result result = JUnitCore.runClasses(TestEmployeeDetails.class);
}
}
}
C:JUNIT_WORKSPACE>javac EmployeeDetails.java
EmpBusinessLogic.java TestEmployeeDetails.java TestRunner.java
Verify the output.
true

TUTORIALS POINT
JUnit Using Assertion
All the assertion are in the Assert class.
public class Assert extends java.lang.Object
This class provides a set of assertion methods useful for writing tests. Only failed assertions are
recorded. Some of the important methods of Assert class are:
1
void assertEquals(boolean expected, boolean actual)
Check that two primitives/Objects are equal
2
void assertTrue(boolean expected, boolean actual)
Check that a condition is true
3
void assertFalse(boolean condition)
Check that a condition is false
4
void assertNotNull(Object object)
Check that an object isn't null.
5
void assertNull(Object object)
Check that an object is null
6
void assertSame(boolean condition)
The assertSame() methods tests if two object references point to the same object
7
void assertNotSame(boolean condition)
The assertNotSame() methods tests if two object references not point to the same object
8
void assertArrayEquals(expectedArray, resultArray);
The assertArrayEquals() method will test whether two arrays are equal to each other.
Let's try to cover all of the above mentioned methods in an example. Create a java class file name
TestAssertions.java in C: > JUNIT_WORKSPACE
import static org.junit.Assert.*;
public class TestAssertions {
CHAPTER
7

TUTORIALS POINT
@Test
public void testAssertions() {
//test data
String str1 = new String ("abc");
String str2 = new String ("abc");
String str3 = null;
String str4 = "abc";
String str5 = "abc";
int val1 = 5;
int val2 = 6;
String[] expectedArray = {"one", "two", "three"};
String[] resultArray = {"one", "two", "three"};
//Check that two objects are equal
assertEquals(str1, str2);
//Check that a condition is true
assertTrue (val1 < val2);
//Check that a condition is false
assertFalse(val1 > val2);
//Check that an object isn't null
assertNotNull(str1);
//Check that an object is null
assertNull(str3);
//Check if two object references point to the same object
assertSame(str4,str5);
//Check if two object references not point to the same object
assertNotSame(str1,str3);
//Check whether two arrays are equal to each other.
assertArrayEquals(expectedArray, resultArray);
}
}
Result result = JUnitCore.runClasses(TestAssertions.class);
}
}
}
C:JUNIT_WORKSPACE>javac TestAssertions.java TestRunner.java

TUTORIALS POINT
Verify the output.
true
Annotation
Annotations are like meta-tags that you can add to you code and apply them to methods or in
class. These annotation in JUnit gives us information about test methods , which methods are
going to run before & after test methods, which methods run before & after all the methods, which
methods or class will be ignore during execution. List of annotations and their meaning in JUnit :
S.N. Annotation & Description
1
@Test
The Test annotation tells JUnit that the public void method to which it is attached can be run
as a test case.
2
@Before
Several tests need similar objects created before they can run. Annotating a public void
method with @Before causes that method to be run before each Test method.
3
@After
If you allocate external resources in a Before method you need to release them after the test
runs. Annotating a public void method with @After causes that method to be run after the
Test method.
4
@BeforeClass
Annotating a public static void method with @BeforeClass causes it to be run once before
any of the test methods in the class.
5
@AfterClass
This will perform the method after all tests have finished. This can be used to perform clean-
up activities.
6
@Ignore
The Ignore annotation is used to ignore the test and that test will not be executed.
Create a java class file name JunitAnnotation.java in C: > JUNIT_WORKSPACE to test annotation
import org.junit.After;
import org.junit.AfterClass;
import org.junit.BeforeClass;
public class JunitAnnotation {
//execute before class
@BeforeClass
public static void beforeClass() {
System.out.println("in before class");
}
//execute after class
@AfterClass
public static void afterClass() {
System.out.println("in after class");

TUTORIALS POINT
}
//execute before test
@Before
public void before() {
System.out.println("in before");
}
//execute after test
@After
public void after() {
System.out.println("in after");
}
//test case
@Test
public void test() {
System.out.println("in test");
}
//test case ignore and will not execute
@Ignore
public void ignoreTest() {
System.out.println("in ignore test");
}
}
execute annotations
Result result = JUnitCore.runClasses(JunitAnnotation.class);
}
}
}
C:JUNIT_WORKSPACE>javac JunitAnnotation.java TestRunner.java
Verify the output.
in before class
in before
in test
in after
in after class
true

TUTORIALS POINT
JUnit Execution Procedure
This tutorial explains the execution procedure of methods in JUnit which means that which
method is called first and which one after that. Here is the execution procedure of the JUint test API
methods with the example.
Create a java class file name JunitAnnotation.java in C: > JUNIT_WORKSPACE to test annotation
import org.junit.After;
import org.junit.AfterClass;
import org.junit.BeforeClass;
public class ExecutionProcedureJunit {
//execute only once, in the starting
@BeforeClass
public static void beforeClass() {
System.out.println("in before class");
}
//execute only once, in the end
@AfterClass
public static void afterClass() {
System.out.println("in after class");
}
//execute for each test, before executing test
@Before
public void before() {
System.out.println("in before");
}
//execute for each test, after executing test
@After
public void after() {
System.out.println("in after");
}
//test case 1
@Test
public void testCase1() {
System.out.println("in test case 1");
}
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TUTORIALS POINT
//test case 2
@Test
public void testCase2() {
System.out.println("in test case 2");
}
}
execute annotations
Result result = JUnitCore.runClasses(ExecutionProcedureJunit.class);
}
}
}
C:JUNIT_WORKSPACE>javac ExecutionProcedureJunit.java TestRunner.java
Verify the output.
in before class
in before
in test case 1
in after
in before
in test case 2
in after
in after class
See the above output and this is how the JUnit execution procedure is.
 First of all beforeClass() method execute only once
 Lastly, the afterClass() method executes only once.
 before() method executes for each test case but before executing the test case.
 after() method executes for each test case but after the execution of test case
 In between before() and after() each test case executes.

TUTORIALS POINT
JUnit Executing Tests
The test cases are executed using JUnitCore class. JUnitCore is a facade for running tests.
It supports running JUnit 4 tests, JUnit 3.8.x tests, and mixtures. To run tests from the command
line, run java org.junit.runner.JUnitCore <TestClass>. For one-shot test runs, use the static method
runClasses(Class[]).
Following is the declaration for org.junit.runner.JUnitCore class:
public class JUnitCore extends java.lang.Object
Here we will see how can we execute the tests with the help of JUnitCore.
Create a Class
/*
*/
//Constructor
}
return message;
}
}
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9

TUTORIALS POINT
 Add a test method testPrintMessage() to your test class.
 Add an Annotaion @Test to method testPrintMessage().
 Implement the test condition and check the condition using assertEquals API of Junit.
@Test
}
}
Next, let's create a java class file name TestRunner.java in C: > JUNIT_WORKSPACE to execute
Test case(s) which import the JUnitCore class and uses the runClasses() method which take the
test class name as parameter.
}
}
}
C:JUNIT_WORKSPACE>javac MessageUtil.java TestJunit.java TestRunner.java
Verify the output.
Hello World
true

TUTORIALS POINT
JUnit Test Suite
Test suite means bundle a few unit test cases and run it together. In JUnit,
both @RunWith and@Suite annotation are used to run the suite test. This tutorial will show you an
example having two TestJunit1 & TestJunit2 test classes to run together using Test Suite.
Create a Class
Create a java class to be tested say MessageUtil.java in C: > JUNIT_WORKSPACE
/*
*/
//Constructor
}
public void printMessage(){
return message;
}
// add "Hi!" to the message
public String salutationMessage(){
message = "Hi!" + message;
return message;
}
}
Create Test Case Classes
CHAPTER
10

TUTORIALS POINT
@Test
assertEquals(message, messageUtil.printMessage());
}
}
@Test
}
}
Create Test Suite Class
 Create a java class.
 Attach @RunWith(Suite.class) Annotation with class.
 Add reference to Junit test classes using @Suite.SuiteClasses annotation
Create a java class file name TestSuite.java in C: > JUNIT_WORKSPACE to execute Test case(s)
import org.junit.runners.Suite;
@RunWith(Suite.class)
@Suite.SuiteClasses({
TestJunit1.class,
TestJunit2.class
})
}
case(s)

TUTORIALS POINT
Result result = JUnitCore.runClasses(JunitTestSuite.class);
}
}
}
Compile all java classes using javac
C:JUNIT_WORKSPACE>javac MessageUtil.java TestJunit1.java
TestJunit2.java JunitTestSuite.java TestRunner.java
Verify the output.
Inside testPrintMessage()
Robert
Inside testSalutationMessage()
Hi Robert
true

TUTORIALS POINT
JUnit Ignore Test
Sometimes it happens that our code is not ready and test case written to test that
method/code will fail if run. The @Ignore annotation helps in this regards.
 A test method annotated with @Ignore will not be executed.
 If a test class is annotated with @Ignore then none of its test methods will be executed.
 Now let's see @Ignore in action.
Create a Class
/*
*/
//Constructor
}
return message;
}
return message;
}
}
CHAPTER
11

TUTORIALS POINT
 Add a test methods testPrintMessage(),testSalutationMessage() to your test class.
 Add an Annotaion @Ignore to method testPrintMessage().
@Ignore
@Test
message = "Robert";
}
@Test
}
}
case(s)
}
}
}
Now run the Test Runner which will not run testPrintMessage() test case defined in provided Test
Case class.

TUTORIALS POINT
Verify the output. testPrintMessage() test case is not tested.
Hi!Robert
true
Now update TestJunit in C: > JUNIT_WORKSPACE to ignore all test cases. Add @Ignore at class
level
@Ignore
@Test
message = "Robert";
}
@Test
}
}
Compile the Test case using javac
C:JUNIT_WORKSPACE>javac TestJunit.java
Now run the Test Runner which will not run any test case defined in provided Test Case class.
Verify the output. No test case is tested.
true

TUTORIALS POINT
JUnit Time Test
Junit provides a handy option of Timeout. If a test case takes more time than specified number
of milliseconds then Junit will automatically mark it as failed. The timeout parameter is used along
with @Test annotation. Now let's see @Test(timeout) in action.
Create a Class
 Create a java class to be tested say MessageUtil.java in C: > JUNIT_WORKSPACE.
 Add a infinite while loop inside printMessage() method.
/*
*/
//Constructor
}
while(true);
}
return message;
}
}
CHAPTER
12

TUTORIALS POINT
 Add timeout of 1000 to testPrintMessage() test case.
@Test(timeout=1000)
messageUtil.printMessage();
}
@Test
}
}
case(s)
}
}
}
Now run the Test Runner which will run test cases defined in provided Test Case class.
Verify the output. testPrintMessage() test case will mark unit testing failed.
Robert
Hi!Robert

TUTORIALS POINT
testPrintMessage(TestJunit): test timed out after 1000 milliseconds
false

TUTORIALS POINT
JUnit Exception Test
Junit provides a option of tracing the Exception handling of code. You can test the code
whether code throws desired exception or not. The expected parameter is used along with
@Test annotation. Now let's see @Test(expected) in action.
Create a Class
 Create a java class to be tested say MessageUtil.java in C: > JUNIT_WORKSPACE.
 Add a error condition inside printMessage() method.
/*
*/
//Constructor
}
int a =0;
int b = 1/a;
}
return message;
}
}
CHAPTER
13

TUTORIALS POINT
 Add expected exception ArithmeticException to testPrintMessage() test case.
@Test(expected = ArithmeticException.class)
messageUtil.printMessage();
}
@Test
}
}
case(s)
}
}
}
Verify the output. testPrintMessage() test case will be passed.
Robert
Hi!Robert
true

TUTORIALS POINT
JUnit Parameterized Test
JUnit 4 has introduced a new feature Parameterized tests. Parameterized tests allow
developer to run the same test over and over again using different values. There are five steps,
that you need to follow to create Parameterized tests.
 Annotate test class with @RunWith(Parameterized.class)
 Create a public static method annotated with @Parameters that returns a Collection of
Objects (as Array) as test data set.
 Create a public constructor that takes in what is equivalent to one "row" of test data.
 Create an instance variable for each "column" of test data.
 Create your tests case(s) using the instance variables as the source of the test data.
The test case will be invoked once per each row of data. Let's see Parameterized tests in action.
Create a Class
 Create a java class to be tested say PrimeNumberChecker.java in C: >
JUNIT_WORKSPACE.
public class PrimeNumberChecker {
public Boolean validate(final Integer primeNumber) {
for (int i = 2; i < (primeNumber / 2); i++) {
if (primeNumber % i == 0) {
return false;
}
}
return true;
}
}
Create Parameterized Test Case Class
 Create a java test class say PrimeNumberCheckerTest.java.
CHAPTER
14

TUTORIALS POINT
Create a java class file name PrimeNumberCheckerTest.java in C: > JUNIT_WORKSPACE
import java.util.Arrays;
import java.util.Collection;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
@RunWith(Parameterized.class)
public class PrimeNumberCheckerTest {
private Integer inputNumber;
private Boolean expectedResult;
private PrimeNumberChecker primeNumberChecker;
@Before
public void initialize() {
primeNumberChecker = new PrimeNumberChecker();
}
// Each parameter should be placed as an argument here
// Every time runner triggers, it will pass the arguments
// from parameters we defined in primeNumbers() method
public PrimeNumberCheckerTest(Integer inputNumber,
Boolean expectedResult) {
this.inputNumber = inputNumber;
this.expectedResult = expectedResult;
}
@Parameterized.Parameters
public static Collection primeNumbers() {
return Arrays.asList(new Object[][] {
{ 2, true },
{ 6, false },
{ 19, true },
{ 22, false },
{ 23, true }
});
}
// This test will run 4 times since we have 5 parameters defined
@Test
public void testPrimeNumberChecker() {
System.out.println("Parameterized Number is : " + inputNumber);
assertEquals(expectedResult,
primeNumberChecker.validate(inputNumber));
}
}
case(s)
Result result = JUnitCore.runClasses(PrimeNumberCheckerTest.class);
}

TUTORIALS POINT
}
}
Compile the PrimeNumberChecker, PrimeNumberCheckerTest and Test Runner classes using
javac
C:JUNIT_WORKSPACE>javac PrimeNumberChecker.java PrimeNumberCheckerTest.java
TestRunner.java
Verify the output.
Parameterized Number is : 2
true

TUTORIALS POINT
JUnit Plug with ANT
In this example, we will demonstrate how to run JUnit using ANT. Let's follow the given
steps:
Step 1: Download Apache Ant
Download Apache Ant
OS Archive name
Windows apache-ant-1.8.4-bin.zip
Linux apache-ant-1.8.4-bin.tar.gz
Mac apache-ant-1.8.4-bin.tar.gz
Step 2: Set Ant Environment
Set the ANT_HOME environment variable to point to the base directory location where ANT
libraries is stored on your machine. For example, We've stored Ant libraries in apache-ant-1.8.4
folder on various Operating Systems as follows.
OS Output
Windows
Set the environment variable ANT_HOME to C:Program FilesApache
Software Foundationapache-ant-1.8.4
Linux export ANT_HOME=/usr/local/apache-ant-1.8.4
Mac export ANT_HOME=/Library/apache-ant-1.8.4
Append Ant compiler location to System Path is as follows for different OS:
OS Output
Windows Append the string ;%ANT_HOMEbin to the end of the system variable, Path.
Linux export PATH=$PATH:$ANT_HOME/bin/
Mac not required
CHAPTER
15

TUTORIALS POINT
Step 3: Download Junit Archive
Download JUnit Archive
OS Archive name
Linux junit4.10.jar
Mac junit4.10.jar
Step 4: Create Project Structure
 Create folder TestJunitWithAnt in C: > JUNIT_WORKSPACE
 Create folder src in C: > JUNIT_WORKSPACE > TestJunitWithAnt
 Create folder test in C: > JUNIT_WORKSPACE > TestJunitWithAnt
 Create folder lib in C: > JUNIT_WORKSPACE > TestJunitWithAnt
 Create MessageUtil class in C: > JUNIT_WORKSPACE > TestJunitWithAnt >
src folder
/*
*/
//Constructor
}
return message;
}
return message;
}
}
 Create TestMessageUtil class in C: > JUNIT_WORKSPACE > TestJunitWithAnt >
src folder

TUTORIALS POINT
public class TestMessageUtil {
@Test
}
@Test
}
}
 Copy junit-4.10.jar in C: > JUNIT_WORKSPACE > TestJunitWithAnt > lib folder
Create ANT Build.xml
We'll be using <junit> task in Ant to execute our Junit test cases.
<project name="JunitTest" default="test" basedir=".">
<property name="testdir" location="test" />
<property name="srcdir" location="src" />
<property name="full-compile" value="true" />
<path id="classpath.base"/>
<path id="classpath.test">
<pathelement location="/lib/junit-4.10.jar" />
<pathelement location="${testdir}" />
<pathelement location="${srcdir}" />
<path refid="classpath.base" />
</path>
<target name="clean" >
<delete verbose="${full-compile}">
<fileset dir="${testdir}" includes="**/*.class" />
</delete>
</target>
<target name="compile" depends="clean">
<javac srcdir="${srcdir}" destdir="${testdir}"
verbose="${full-compile}">
<classpath refid="classpath.test"/>
</javac>
</target>
<target name="test" depends="compile">
<junit>
<classpath refid="classpath.test" />
<formatter type="brief" usefile="false" />
<test name="TestMessageUtil" />
</junit>
</target>
</project>
Run the following ant command
C:JUNIT_WORKSPACETestJunitWithAnt>ant
Verify the output.

TUTORIALS POINT
Buildfile: C:JUNIT_WORKSPACETestJunitWithAntbuild.xml
clean:
compile:
[javac] Compiling 2 source files to C:JUNIT_WORKSPACETestJunitWithAnttest
[javac] [parsing started C:JUNIT_WORKSPACETestJunitWithAntsrc
MessageUtil.java]
[javac] [parsing completed 18ms]
[javac] [parsing started C:JUNIT_WORKSPACETestJunitWithAntsrc
TestMessageUtil.java]
[javac] [parsing completed 2ms]
[javac] [search path for source files: C:JUNIT_WORKSPACE
TestJunitWithAntsrc]
[javac] [loading javalangObject.class(javalang:Object.class)]
[javac] [loading javalangString.class(javalang:String.class)]
[javac] [loading orgjunitTest.class(orgjunit:Test.class)]
[javac] [loading orgjunitIgnore.class(orgjunit:Ignore.class)]
[javac] [loading orgjunitAssert.class(orgjunit:Assert.class)]
[javac] [loading javalangannotationRetention.class
(javalangannotation:Retention.class)]
[javac] [loading javalangannotationRetentionPolicy.class
(javalangannotation:RetentionPolicy.class)]
[javac] [loading javalangannotationTarget.class
(javalangannotation:Target.class)]
[javac] [loading javalangannotationElementType.class
(javalangannotation:ElementType.class)]
[javac] [loading javalangannotationAnnotation.class
(javalangannotation:Annotation.class)]
[javac] [checking MessageUtil]
[javac] [loading javalangSystem.class(javalang:System.class)]
[javac] [loading javaioPrintStream.class(javaio:PrintStream.class)]
[javac] [loading javaioFilterOutputStream.class
(javaio:FilterOutputStream.class)]
[javac] [loading javaioOutputStream.class(javaio:OutputStream.class)]
[javac] [loading javalangStringBuilder.class
(javalang:StringBuilder.class)]
[javac] [loading javalangAbstractStringBuilder.class
(javalang:AbstractStringBuilder.class)]
[javac] [loading javalangCharSequence.class(javalang:CharSequence.class)]
[javac] [loading javaioSerializable.class(javaio:Serializable.class)]
[javac] [loading javalangComparable.class(javalang:Comparable.class)]
[javac] [loading javalangStringBuffer.class(javalang:StringBuffer.class)]
[javac] [wrote C:JUNIT_WORKSPACETestJunitWithAnttestMessageUtil.class]
[javac] [checking TestMessageUtil]
[javac] [wrote
C:JUNIT_WORKSPACETestJunitWithAnttestTestMessageUtil.class]
[javac] [total 281ms]
test:
[junit] Testsuite: TestMessageUtil
[junit] Tests run: 2, Failures: 0, Errors: 0, Time elapsed: 0.008 sec
[junit]
[junit] ------------- Standard Output ---------------
[junit] Inside testPrintMessage()
[junit] Robert
[junit] Inside testSalutationMessage()
[junit] Hi!Robert
[junit] ------------- ---------------- ---------------
BUILD SUCCESSFUL
Total time: 0 seconds

TUTORIALS POINT
JUnit Plug with Eclipse
To setup JUnit with eclipse following steps need to be followed
Step 1: Download Junit archive
Download JUnit
OS Archive name
Linux junit4.10.jar
Mac junit4.10.jar
Assume you copied above JAR file in C:>JUnit folder.
Step 2: Set Eclipse environment
 Open eclipse -> right click on project and click on property > Build Path > Configure
Build Path and add the junit-4.10.jar in the libraries using Add External Jar button.
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16

TUTORIALS POINT
 We assume that your eclipse has inbuilt Junit plugin if it is not available in
C:>eclipse/plugins directory, then you can download it from JUnit Plugin. Unzip the
downloaded zip file in the plugin folder of the eclipse. Finally restart eclipse.
 Now your eclipse is ready for the development of JUnit test cases.
Step 3: Verify Junit installation in Eclipse
 Create a projet TestJunit in eclipse at any location.
 Create a class MessageUtil to test in the project
/*
*/
//Constructor
}

TUTORIALS POINT
return message;
}
}
 Create a test class TestJunit in the project
@Test
}
}
Following should be the project structure
Finally, verify the output of the program by right click on program and run as junit

TUTORIALS POINT
Verify the result

TUTORIALS POINT
JUnit Extensions
Following are few important JUnit extensions
 Cactus
 JWebUnit
 XMLUnit
 MockObject
Cactus
Cactus is a simple test framework for unit testing server-side java code (Servlets, EJBs, Tag Libs,
Filters). The intent of Cactus is to lower the cost of writing tests for server-side code. It uses JUnit
and extends it. Cactus implements an in-container strategy, meaning that tests are executed
inside the container.
The Cactus Ecosystem is made of several components:
 The Cactus Framework: This is the heart of Cactus. It is the engine that provides the API
to write Cactus tests.
 The Cactus Integration Modules: They are front ends and frameworks that provide easy
ways of using the Cactus Framework (Ant scripts, Eclipse plugin, Maven plugin).
 The Cactus Samples: They are simple projects that demonstrate how to write Cactus
tests and how to use some of the Integration Modules.
JWebUnit
JWebUnit is a Java-based testing framework for web applications. It wraps existing testing
frameworks such as HtmlUnit and Selenium with a unified, simple testing interface to allow you to
quickly test the correctness of your web applications.
CHAPTER
17

TUTORIALS POINT
JWebUnit provides a high-level Java API for navigating a web application combined with a set of
assertions to verify the application's correctness. This includes navigation via links, form entry and
submission, validation of table contents, and other typical business web application features.
The simple navigation methods and ready-to-use assertions allow for more rapid test creation
than using only JUnit or HtmlUnit. And if you want to switch from HtmlUnit to other plugins such as
Selenium (available soon), there is no need to rewrite your tests.
XMLUnit
XMLUnit provides classes to validate or compare XML files or to assert the value of XPath
expressions applied to them. XMLUnit for Java provides integration with JUnit while XMLUNit for
.NET integrates with NUnit to simplify unit testing code that generates XML.
MockObject
In a unit test, mock objects can simulate the behavior of complex, real (non-mock) objects and are
therefore useful when a real object is impractical or impossible to incorporate into a unit test. The
common coding style for testing with mock objects is to:
 Create instances of mock objects
 Set state and expectations in the mock objects
 Invoke domain code with mock objects as parameters
 Verify consistency in the mock objects

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