![?
for (i = 0; i < m; i++) {
free(a[i])
;
}
free(a);
// Trick Question ! Nothing :)
C Java](https://image.slidesharecdn.com/futureofjava3-220909161536-379f0efb/85/The-Future-of-JVM-Languages-16-320.jpg)
![public class ObjectExample {
private int value;
private String name;
public ObjectExample(int value, String name) {
this.value = value;
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public static void main(String[] args) {
ObjectExample object = new ObjectExample(1,"Awesome");
System.out.println("Name " + object.getName() + " Value " + object.getValue());
}
}
Java -> Groovy Objects
class ObjectExample {
int value
String name
}
object = new ObjectExample(value:1,name:"Awesome")
println "Name $object.name Value $object.value"
implicit Getters/Setters
semi colons optional
parentheses optional
interpolated Strings
named properties in Constructor
static void main not needed
variable type optional
default static imports](https://image.slidesharecdn.com/futureofjava3-220909161536-379f0efb/85/The-Future-of-JVM-Languages-23-320.jpg)
![import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class Main {
public static void main(String[] args) {
List<Integer> someItems = Arrays.asList(new Integer[]{1, 2, 3, 4});
for (Integer item : someItems) {
System.out.println(item);
}
Map<String, String> someMapping = new HashMap<>();
someMapping.put("ST", "started");
someMapping.put("IP", "in progress");
someMapping.put("DN", "done");
for (Map.Entry<String, String> entry : someMapping.entrySet()) {
String key = entry.getKey();
String value = entry.getValue();
System.out.println(key + " => " + value);
}
}
}
Java -> Groovy Collections
def someItems = [1, 2, 3, 4]
someItems.each {
println it
}
def someMapping = ["ST": "started", "IP": "in progress", "DN": "done"]
someMapping.each { key, val ->
println "$key => $val"
}
collection literals
default collection imports
closure parameter def optional (it)](https://image.slidesharecdn.com/futureofjava3-220909161536-379f0efb/85/The-Future-of-JVM-Languages-26-320.jpg)
![import java.sql.*;
import java.util.ArrayList;
import java.util.List;
public class JavaSqlExample {
static class Book {
public String name;
public int price;
public Book(String name, int price) {
this.name = name;
this.price = price;
}
}
public static void main(String[] args) throws SQLException{
List<Book> books = new ArrayList<>();
try (Connection con = DriverManager.getConnection("jdbc:h2:mem:")) {
con.prepareStatement("CREATE TABLE books " +
"AS SELECT 'Animal Farm' AS name, 123 AS price").execute();
try (ResultSet rs = con.prepareStatement("SELECT * FROM books").executeQuery()) {
while (rs.next()) {
books.add(new Book(rs.getString("name"), rs.getInt("price")));
}
}
}
books.forEach((book) -> System.out.println("Book " + book.name + " Price - " + book.price));
}
}
Java -> Groovy SQL
def sql = Sql.newInstance "jdbc:h2:mem:"
sql.execute """
CREATE TABLE books
AS SELECT 'Animal Farm' AS name, 123 AS price
"""
sql.rows "SELECT * FROM books" each {
println "Book - $it.name , Price - $it.price"
}
sql.close()
multiline strings
dynamic types
simpli
fi
ed SQL](https://image.slidesharecdn.com/futureofjava3-220909161536-379f0efb/85/The-Future-of-JVM-Languages-27-320.jpg)
The Future of JVM Languages
- 1. THE FUTURE OF JVM LANGUAGES AND THE EVOLUTION OF PROGRAMMING LANGUAGES Victor Szoltysek
- 2. 4 MODERN JVM LANGUAGES
- 4. 1969
- 5. - Margaret Hamilton (with stacks of assembly code she wrote for the first moon landing mission)
- 7. ? 43 00 00 00 inc ebx MACHINE CODE ASSEMBLY
- 9. No matter the programming language chosen, a professional developer will write an average of 10 lines of code (LoC) day. Frederick Brooks
- 10. 1980
- 11. 1980 - MOBILE
- 12. ? mov eax, $ x cmp eax, 0x0C jg en d beginning: inc eax cmp eax, 0x0C jle beginnin g end: while(x <= 12) { x++; } ASSEMBLY C
- 13. OLDER LANGUAGES STILL USED
- 14. 2000
- 15. 2000 - MOBILE
- 16. ? for (i = 0; i < m; i++) { free(a[i]) ; } free(a); // Trick Question ! Nothing :) C Java
- 18. * Famous Linus Torvalds C++ rant! OLDER LANGUAGES STILL USED
- 19. 2022
- 20. 2022 - MOBILE
- 21. - Java 8 (circa 2022) The reports of my death are greatly exaggerated. OLDER LANGUAGES STILL USED
- 22. 4 MODERN JVM LANGUAGES
- 23. public class ObjectExample { private int value; private String name; public ObjectExample(int value, String name) { this.value = value; this.name = name; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getValue() { return value; } public void setValue(int value) { this.value = value; } public static void main(String[] args) { ObjectExample object = new ObjectExample(1,"Awesome"); System.out.println("Name " + object.getName() + " Value " + object.getValue()); } } Java -> Groovy Objects class ObjectExample { int value String name } object = new ObjectExample(value:1,name:"Awesome") println "Name $object.name Value $object.value" implicit Getters/Setters semi colons optional parentheses optional interpolated Strings named properties in Constructor static void main not needed variable type optional default static imports
- 24. public class ObjectExample { private int value; private String name; public ObjectExample(int value, String name) { this.value = value; this.name = name; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getValue() { return value; } public void setValue(int value) { this.value = value; } } Java -> Scala Objects case class ObjectExample(value: Int, name: String)
- 25. public class ObjectExample { private int value; private String name; public ObjectExample(int value, String name) { this.value = value; this.name = name; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getValue() { return value; } public void setValue(int value) { this.value = value; } } Java 8 -> Java 14 Records public record ObjectExample(int value, String name)
- 26. import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; public class Main { public static void main(String[] args) { List<Integer> someItems = Arrays.asList(new Integer[]{1, 2, 3, 4}); for (Integer item : someItems) { System.out.println(item); } Map<String, String> someMapping = new HashMap<>(); someMapping.put("ST", "started"); someMapping.put("IP", "in progress"); someMapping.put("DN", "done"); for (Map.Entry<String, String> entry : someMapping.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); System.out.println(key + " => " + value); } } } Java -> Groovy Collections def someItems = [1, 2, 3, 4] someItems.each { println it } def someMapping = ["ST": "started", "IP": "in progress", "DN": "done"] someMapping.each { key, val -> println "$key => $val" } collection literals default collection imports closure parameter def optional (it)
- 27. import java.sql.*; import java.util.ArrayList; import java.util.List; public class JavaSqlExample { static class Book { public String name; public int price; public Book(String name, int price) { this.name = name; this.price = price; } } public static void main(String[] args) throws SQLException{ List<Book> books = new ArrayList<>(); try (Connection con = DriverManager.getConnection("jdbc:h2:mem:")) { con.prepareStatement("CREATE TABLE books " + "AS SELECT 'Animal Farm' AS name, 123 AS price").execute(); try (ResultSet rs = con.prepareStatement("SELECT * FROM books").executeQuery()) { while (rs.next()) { books.add(new Book(rs.getString("name"), rs.getInt("price"))); } } } books.forEach((book) -> System.out.println("Book " + book.name + " Price - " + book.price)); } } Java -> Groovy SQL def sql = Sql.newInstance "jdbc:h2:mem:" sql.execute """ CREATE TABLE books AS SELECT 'Animal Farm' AS name, 123 AS price """ sql.rows "SELECT * FROM books" each { println "Book - $it.name , Price - $it.price" } sql.close() multiline strings dynamic types simpli fi ed SQL
- 28. BufferedReader br = new BufferedReader(new FileReader("file.txt")); try { StringBuilder sb = new StringBuilder(); String line = br.readLine(); while (line != null) { sb.append(line); sb.append(System.lineSeparator()); line = br.readLine(); } String everything = sb.toString(); } finally { br.close(); } Java -> Groovy everything = new File("file.txt").text many built in convenience methods ( fi les, xml, json, rest, console) Process p = new ProcessBuilder("ifconfig", “en0").start(); BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream())); String line = br.readLine(); while(line != null){ System.out.println(line); line = br.readLine(); } println "ifconfig en0".execute().text
- 29. Groovy Goodness if ((1.1 + 0.1) == 1.2) System.out.println("Matches in Groovy, NOT!! in Java"); big decimal by default execute directly on Unix (#) #!/usr/bin/env groovy println("Hello world") chmod +x helloWorl d ./helloWorld @Grab(group='org.springframework', module='spring', version='2.5.6') import org.springframework.jdbc.core.JdbcTemplate download dependencies String.metaClass.shout = { delegate.toUpperCase() } println "Hello!".shout() add methods to existing classes return optional
- 30. String version = "UNKNOWN"; if(computer != null){ Soundcard soundcard = computer.getSoundcard(); if(soundcard != null){ USB usb = soundcard.getUSB(); if(usb != null){ version = usb.getVersion(); } } } Java -> Groovy version = computer?.getSoundcard()?.getUSB()?.getVersion() ?: "UNKNOWN"; elvis operator (?:) safe navigation operator (?.) public List<String> decrypt(List<String> encryptedText) { return encryptedText.stream() .map(this::decryptText) .collect(Collectors.toList()); } public List<String> decrypt(List<String> encryptedText) { return encryptedText*.decryptText } spread dot operator (*.)
- 31. Groovy Testing (Power Asserts) Condition not satisfied : 'Grails Goodness' == course.descriptio n | | | | | Groovy Goodnes s | com.mrhaki.blog.Course@3435ec 9 fals e 4 differences (73% similarity ) Gr(ails) Goodnes s Gr(oovy) Goodness assert 'Grails Goodness' == course.description
- 32. Groovy Testing (Spock) def "addition test "() { when: "2 is added to 2" int sum = 2 + 2 then: "sum should be 4" sum == 4 }
- 33. Groovy Testing (Spock) Parametrized Inputs def "Data Drive test - minimum of #a and #b is #c"() { expect : Math.min(a, b) == c where : a | b || c 3 | 7 || 3 5 | 4 || 4 9 | 9 || 9 }
- 34. Groovy Testing (Spock+Geb) Web Application Testing def "API example (non-Html content) -- health check"() { given: go "https://status.github.com/api/status.json" expect : $('pre').text().startsWith('{"status":"good"' ) }
- 35. Groovy Building (Gradle) apply plugin:'java' apply plugin:'checkstyle' apply plugin:'findbugs' apply plugin:'pmd' version ='1.0' repositories { mavenCentral() } dependencies { testCompile group:'junit', name:'junit', version:'4.11' }
- 36. vs XML Building (Maven) <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-checkstyle-plugin</artifactId> <version>2.12.1</version> <executions> <execution> <configuration> <configLocation>config/checkstyle/checkstyle.xml</configLocation> <consoleOutput>true</consoleOutput> <failsOnError>true</failsOnError> </configuration> <goals> <goal>check</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>findbugs-maven-plugin</artifactId> <version>2.5.4</version> <executions> <execution> <goals> <goal>check</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-pmd-plugin</artifactId> <version>3.1</version> <executions> <execution> <goals> <goal>check</goal> </goals> </execution> </executions> </plugin>
- 37. Groovy Building (Gradle) Signi fi cant Performance over Maven
- 38. Java 10+ Type Inference var list = new ArrayList<String>(); // infers ArrayList<String > var stream = list.stream(); // infers Stream<String>
- 39. Java 13+ Switch Expressions switch (day) { case MONDAY, FRIDAY, SUNDAY -> System.out.println(6) ; case TUESDAY -> System.out.println(7) ; case THURSDAY, SATURDAY -> System.out.println(8) ; case WEDNESDAY -> System.out.println(9) ; }
- 40. Java 15+ Text Blocks public String textBlocks() { return "" " Get busy livin g o r get busy dying . --Stephen King""" ; }
- 41. Led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years. Tony Hoare (on his invention of the null reference)
- 42. Kotlin - True Null Safety var a: String = "abc" a = null // compilation error
- 43. WHICH JVM LANGUAGE TO USE ? (AND WHY STICK TO THE JVM?)
- 44. ▸Steep Learning Curve ▸Compatibility Issues ▸Lackluster IDE Support ▸Negative Market Trend ▸Including Companies moving back to Java (including Twitter) ▸Opinion -> Strong Pass * SCALA Rare niches aside (Big Data)
- 45. GROOVY ▸Easy Learning Curve ▸Strong Industry and IDE Support (JetBrains/Google) ▸Dynamic Typing (a double edged sword) ▸Slowed Adoption ▸Opinion -> Consider (for build scripts and testing) ▸Prefer Gradle over Maven :)
- 46. ▸Strong Industry and IDE Support ▸Modern Java 19+ features have still no caught up with alternatives ▸Opinion -> Consider JAVA 19+ (OR 8)
- 47. ▸Easy Learning Curve ▸Strong Industry and IDE Support (JetBrains/Google) ▸True Null Safety ▸Gradle Scripts can be written in Kotlin ▸Opinion -> Strong Consider (especially for Android) KOTLIN
- 50. ▸Abstraction as a Core Productivity Accelerator ▸Diminishing returns with Higher Level Languages ▸Stronger returns are often elsewhere (frameworks, cloud, etc) ▸Consider Kotlin / Groovy (testing / building) / Scala as JVM alternatives ▸Java isn’t going away TAKEAWAYS