GenericConversionService converts to null when targetType is a primitive resulting in binding error [SPR-6179]

[spring-projects-issues]

Keith Donald opened SPR-6179 and commented

Say I'm binding a String to a int (primitive). If the source String property is null, the value to bind to the target will also be null. Unfortunately, null cannot be set as a value for a primitive and the result is an IllegalArgumentException. For conversions that result in null, the GenericConversionService should see if the target type is a primitive; if so the value returned should be the equivalent of null for that primitive (0 for ints,longs, etc, false for boolean).

See example stack trace of this occurring and how cryptic it is at present:

map String age (value == null) -> int age (value == "" results in the same with a DefaultConversionService)

---

org.springframework.mapping.MappingException: 1 mapping failure(s) occurred: #1) EL1034E:(pos 0): A problem occurred whilst attempting to set the property 'age': Unable to access property 'age' through setter
at org.springframework.mapping.support.SpelMapper.map(SpelMapper.java:104)
at org.springframework.mapping.support.SpelMapperTests.mapBeanDeep(SpelMapperTests.java:125)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Failure cause traces:

• MappingFailure Spring core JMS pom.xml #1 Cause:
  org.springframework.expression.spel.SpelEvaluationException: EL1034E:(pos 0): A problem occurred whilst attempting to set the property 'age': Unable to access property 'age' through setter
  at org.springframework.expression.spel.ast.PropertyOrFieldReference.writeProperty(PropertyOrFieldReference.java:213)
  at org.springframework.expression.spel.ast.PropertyOrFieldReference.setValue(PropertyOrFieldReference.java:111)
  at org.springframework.expression.spel.SpelExpression.setValue(SpelExpression.java:116)
  at org.springframework.mapping.support.Mapping.map(Mapping.java:71)
  at org.springframework.mapping.support.SpelMapper.map(SpelMapper.java:101)
  at org.springframework.mapping.support.SpelMapperTests.mapBeanDeep(SpelMapperTests.java:125)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
  at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
  at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
  Caused by: org.springframework.expression.AccessException: Unable to access property 'age' through setter
  at org.springframework.expression.spel.support.ReflectivePropertyResolver.write(ReflectivePropertyResolver.java:210)
  at org.springframework.expression.spel.ast.PropertyOrFieldReference.writeProperty(PropertyOrFieldReference.java:208)
  ... 27 more
  Caused by: java.lang.IllegalArgumentException
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at org.springframework.expression.spel.support.ReflectivePropertyResolver.write(ReflectivePropertyResolver.java:206)
  ... 28 more

---

Affects: 3.0 RC1

Referenced from: commits e7c8f1e