Regression in support for property write method return type covariance [SPR-8432]

[spring-projects-issues]

Stepan Koltsov opened SPR-8432 and commented

Regression in 3.1 M2. When subclass overrides getter with narrower return type, Spring fails to set property.

 
public class ReadWritePropertyErrorMain { 

    public static void main(String[] args) { 

        final String contextXml = 
            "<beans xmlns='http://www.springframework.org/schema/beans&#39;" + 
            " xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance&#39;" + 
            " xsi:schemaLocation='" + 
            " http://www.springframework.org/schema/beans" + 
            " http://www.springframework.org/schema/beans/spring-beans-3.0.xsd" + 
            " '" + 
            ">" + 
            " <bean id='t' class='" + MyTemplate5.class.getName() + "'/>" + 
            " <bean class='" + MyDaoSupport5.class.getName() + "'>" + 
            " <property name='myTemplate4' ref='t'/>" + 
            " </bean>" + 
            "</beans>"; 

        AbstractXmlApplicationContext applicationContext = new AbstractXmlApplicationContext() { 
            @Override 
            protected Resource[] getConfigResources() { 
                return new Resource[] { new ByteArrayResource(contextXml.getBytes()) }; 
            } 
        }; 

        applicationContext.refresh(); 

        System.out.println("$"); 
    } 
} 

public class MyDaoSupport4 { 

    private MyTemplate4 myTemplate4; 

    public void setMyTemplate4(MyTemplate4 jdbcTemplate4) { 
        this.myTemplate4 = jdbcTemplate4; 
    } 

    public MyTemplate4 getMyTemplate4() { 
        return myTemplate4; 
    } 

} 

public class MyDaoSupport5 extends MyDaoSupport4 { 

    @Override 
    public MyTemplate5 getMyTemplate4() { // <-- narrow subtype is here 
        return (MyTemplate5) super.getMyTemplate4(); 
    } 

} 

public class MyTemplate4 { } 

public class MyTemplate5 extends MyTemplate4 { } 

Error:

 
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ru.yandex.commune.junk.stepancheg.spring.readWrite.MyDaoSupport5#0' defined in resource loaded from byte array: Initialization of bean failed; nested exception is java.lang.IllegalStateException: Read and write parameter types are not the same 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) 
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) 
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) 
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) 
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) 
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580) 
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913) 
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464) 
at ru.yandex.commune.junk.stepancheg.spring.readWrite.ReadWriteProperty.main(ReadWriteProperty.java:36) 
Caused by: java.lang.IllegalStateException: Read and write parameter types are not the same 
at org.springframework.core.convert.Property.resolveMethodParameter(Property.java:137) 
at org.springframework.core.convert.Property.<init>(Property.java:56) 
at org.springframework.beans.BeanWrapperImpl.property(BeanWrapperImpl.java:1174) 
at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:497) 
at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:490) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1371) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1330)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1086) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) 
... 9 more 

---

Affects: 3.1 M2

Attachments:

• mylyn-context.zip (8.61 kB)

Issue Links:

• Overhaul non-void JavaBean write method support [SPR-10029] #14663 Overhaul non-void JavaBean write method support

Referenced from: commits 4a8be69, 0ee1256, 5dc2d56

[spring-projects-issues]

Stepan Koltsov commented

This worked in 3.1 M1.

[spring-projects-issues]

Chris Beams commented

This very likely has to do with the introduction of ExtendedBeanInfo in 3.1 M2

[spring-projects-issues]

Chris Beams commented

Thanks for catching this, Stepan.

In fact, it did not have to do with the introduction of ExtendedBeanInfo in Spring 3.1 M2, but rather a different new class, see below.

commit 4551864289d5ef0c6b0f31d606ffc6129e735401 (HEAD, SPR-8432)
Author: Chris Beams <cbeams@vmware.com>
Date:   Thu Jun 16 15:40:24 2011 +0800

    Fix regression with covariant property return types
    
    Prior to this change, the Property class introduced in 3.1 M2 validated
    read/write property method pairs based on whether their parameter/return
    types were equal to one another.  This precluded the valid possibility
    of read method that returns a subtype of the write method's parameter
    type, and represented a regression against 3.1 M1 and earlier versions.
    
    The implementation now uses isAssignableFrom rather than a straight
    equals check against the types.
    
    Issue: SPR-8432

[spring-projects-issues]

Chris Beams commented

A general note to watchers of ExtendedBeanInfo-related issues: #14663 is a major refactoring of ExtendedBeanInfo and overall support for non-void returning setter methods.

If you have submitted a reproduction project with this issue, we have run it through its paces against these new changes, but we would like to ask you to do the same against your actual applications.

Please consider updating your dev or test builds to work against 3.1.4.BUILD-SNAPSHOT and/or 3.2.0.BUILD-SNAPSHOT to verify, and we would appreciate any feedback, even if it's to let us know that all is well. So that we can consolidate feedback, please add your comments to #14663, and mention the original issue(s) that you were watching.

Thanks!

Note also that testing against 3.1.4 is preferable to 3.2.0 because ExtendedBeanInfo is always in the code path in the latter, while in 3.2.0 we've optimized things such that ExtendedBeanInfo is only in play for bean classes that have one or more non-void returning setter methods.