WritableResource doesn't have parity with Resource in @Value etc. [SPR-10656]

[spring-projects-issues]

Dave Syer opened SPR-10656 and commented

Users can (and often do) inject Resource instances using placeholders and pattern matching, but this doesn't work with WritableResource. It might be an oversight?

---

Affects: 4.0 M1

1 votes, 4 watchers

[spring-projects-issues]

Phil Webb commented

Can you provide a small snippet of code to demonstrate what you mean?

[spring-projects-issues]

Dave Syer commented

This would fail to bind to the environment property:

@Component
public class MyWritingStuff {

@Value("${writing.file:file:/tmp/foo.txt}")
private WritableResource writable;

}

whereas this would succeed:

@Component
public class MyReadingStuff {

@Value("${writing.file:file:/tmp/foo.txt}")
private Resource writable;

}

[spring-projects-issues]

Phil Webb commented

I think I have a fix for this but it changes the default behavior of DefaultResourceLoader. Juergen Hoeller, could you review and let me know how risky you think this is?

#301

[spring-projects-issues]

Artem Bilan commented

Some our projects have started to bump to this issue, too: spring-attic/spring-cloud-gcp#72

Wouldn't it be great to revise the fix?

Thanks

[spring-projects-issues]

Bulk closing outdated, unresolved issues. Please, reopen if still relevant.

[fmbenhassine]

Please, reopen if still relevant.

This issue is still relevant with SF 6.0.0 snapshots. Can you please take a look? This is actually blocking for spring-projects/spring-batch#756.

[jhoeller]

@benas are you specifically trying to inject an @Value WritableResource which isn't working out of the box? Can you confirm that @Value Resource with a subsequent downcast to WritableResource works (since we attempt to resolve a FileUrlResource there as of 5.0.2)? That would mean that we only have to add a ResourceEditor registration for WritableResource.

[fmbenhassine]

Thank you for your feedback, Juergen.

are you specifically trying to inject an @Value WritableResource which isn't working out of the box?

Yes, I used the same sample as in this comment with the latest SF 6.0 snapshots. To give a bit of context, my specific use case is in Batch (issue spring-projects/spring-batch#756) where a change from Resource to WritableResource in AbstractFileItemWriter results in a failure to load this application context (The sample is in XML config, but I guess the configuration style should not matter). The sample fails with:

[main] ERROR org.springframework.batch.core.step.AbstractStep - Encountered an error executing step step1 in job ioSampleJob
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.itemWriter' defined in class path resource [jobs/iosample/delimited.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource' for property 'resource'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource' for property 'resource': no matching editors or conversion strategy found
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:611)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:525)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$1(AbstractBeanFactory.java:365)
	at org.springframework.batch.core.scope.StepScope.get(StepScope.java:113)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:362)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:35)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:195)
	at jdk.proxy2/jdk.proxy2.$Proxy21.open(Unknown Source)
	at org.springframework.batch.item.support.CompositeItemStream.open(CompositeItemStream.java:131)
	at org.springframework.batch.core.step.tasklet.TaskletStep.open(TaskletStep.java:310)
	at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:216)
	at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:152)
	at org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep(JobFlowExecutor.java:68)
	at org.springframework.batch.core.job.flow.support.state.StepState.handle(StepState.java:68)
	at org.springframework.batch.core.job.flow.support.SimpleFlow.resume(SimpleFlow.java:170)
	at org.springframework.batch.core.job.flow.support.SimpleFlow.start(SimpleFlow.java:145)
	at org.springframework.batch.core.job.flow.FlowJob.doExecute(FlowJob.java:137)
	at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:332)
	at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:149)
	at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50)
	at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:140)
	at org.springframework.batch.test.JobLauncherTestUtils.launchJob(JobLauncherTestUtils.java:156)
	at org.springframework.batch.sample.iosample.AbstractIoSampleTests.testUpdateCredit(AbstractIoSampleTests.java:72)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
	at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource' for property 'resource'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource' for property 'resource': no matching editors or conversion strategy found
	at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:595)
	at org.springframework.beans.AbstractNestablePropertyAccessor.convertForProperty(AbstractNestablePropertyAccessor.java:609)
	at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:190)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1700)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1656)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1400)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602)
	... 54 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource' for property 'resource': no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:262)
	at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:590)
	... 60 more

Can you confirm that @Value Resource with a subsequent downcast to WritableResource works (since we attempt to resolve a FileUrlResource there as of 5.0.2)?

I'm not sure if this is a regression or not, but the following snippet fails with a ClassCastException with the latest 6.0 snapshots:

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.WritableResource;
import org.springframework.stereotype.Component;

@Configuration
public class WritableResourceConversionSample {

    public static void main(String[] args) throws Exception {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(WritableResourceConversionSample.class);
        MyService myService = applicationContext.getBean(MyService.class);
        myService.printMessage(); // fails with java.lang.ClassCastException: class org.springframework.core.io.DefaultResourceLoader$ClassPathContextResource cannot be cast to class org.springframework.core.io.WritableResource
    }

    @Component
    public static class MyService {

        @Value("${file:/tmp/myWritableFile.txt}")
        private Resource resource;// With a WritableResource here, the sample fails at startup with an IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.io.WritableResource': no matching editors or conversion strategy found

        public void printMessage() {
            System.out.println(((WritableResource) resource).isWritable());
        }
    }

}

Let me know if you need more details on this. Thank you upfront.