NullPointerException in InjectionMetadata [SPR-7686]

[spring-projects-issues]

Christophe Roudet opened SPR-7686 and commented

When using SpringBeanAutowiringSupport.processInjectionBasedOnServletContext()
a NullPointerException is raised in
InjectionMetadata.checkPropertySkipping(PropertyValues pvs)

protected boolean checkPropertySkipping(PropertyValues pvs) {
  if (this.skip == null) {
    synchronized (pvs) { // <-- NullPointerException
      if (this.skip == null) {

in AutowiredAnnotationBeanPostProcessor.processInjection(Object bean)
metadata inject is called with null for PropertyValues

public void processInjection(Object bean) throws BeansException {
  Class<?> clazz = bean.getClass();
  InjectionMetadata metadata = findAutowiringMetadata(clazz);
  try {
    metadata.inject(bean, null, null); // <-- pvs is null
  }
  catch (Throwable ex) {
    throw new BeanCreationException("Injection of autowired dependencies failed for class [" + clazz + "]", ex);
  }
}

Here is the stack trace:

java.lang.NullPointerException
 	at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.checkPropertySkipping(InjectionMetadata.java:171)
 	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:526)
 	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)
 	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.processInjection(AutowiredAnnotationBeanPostProcessor.java:300)
 	at org.springframework.web.context.support.SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(SpringBeanAutowiringSupport.java:110)

---

Affects: 3.0.5

Issue Links:

• NullPointerException could be thrown on synchronized (pvs) in InjectionMetadata.checkPropertySkipping [SPR-7688] #12344 NullPointerException could be thrown on synchronized (pvs) in InjectionMetadata.checkPropertySkipping ("is duplicated by")
• Unresolved thread safety issue in AutowiredAnnotationBeanPostProcessor.AutowiredMethodElement [SPR-7635] #12291 Unresolved thread safety issue in AutowiredAnnotationBeanPostProcessor.AutowiredMethodElement

Referenced from: commits 9c64ac7

1 votes, 4 watchers

[spring-projects-issues]

Christophe Roudet commented

I think it is related to the fix for #12298.

[spring-projects-issues]

Henrik Heimbuerger commented

First of all, this not only affects processInjectionBasedOnServletContext(), but also processInjectionBasedOnCurrentContext().

Why is this prioritized as minor? It completely breaks the subclassing of SpringBeanAutowiringSupport, because its constructor always calls processInjectionBasedOnCurrentContext(). I don't see how I could upgrade to 3.0.5 as long as this bug is in place.

Is there an easy workaround that I'm missing, except for not using SpringBeanAutowiring at all?

[spring-projects-issues]

Christophe Roudet commented

If you can put the annotations on the fields rather than on the methods, it will work.

  @Autowired
  public void setXXXX(XXXX xxxx) {
    this.xxxx = xxxx;
  }

  ...

--->

  @Autowired
  private XXXX xxxx;

  ...

[spring-projects-issues]

Henrik Heimbuerger commented

As I said, the problem is not @Autowired, it's subclassing SpringBeanAutowiringSupport. (Or at least I'm not getting to the point where @Autowired would be a problem because of that.)

[spring-projects-issues]

Florian Feigenbutz commented

Henrik, as Christophe said you can bypass this bug in 3.0.5 by placing the @Autowired annotations to the fields instead of the setter methods.

This causes Spring to use the inject() method of
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.AutowiredFieldElement
instead of
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.AutowiredMethodElement

As the bug only affects the latter one no NPEs should be caused even if you're subclassing SpringBeanAutowiringSupport.

[spring-projects-issues]

Paul Benedict commented

Anymore 3.0 maintenance releases coming out? Can this be backported? -- Nevermind, I see it's fixed in 3.0.6.