7

GWT で AutoBean を使用してリストをシリアル化する方法を見つけようとしていますが、Null Pointer Exception が引き続き発生します。

ここに私が持っているものがあります:

    GuideCreatorFactory beanFactory = AutoBeanFactorySource.create(GuideCreatorFactory.class);

    List<Guide> guides = new LinkedList<Guide>();
    Guide guide = new Guide();
    guide.setText("this is the text");
    guide.setTitle("this is the title");
    guides.add(guide);

    GuideCreatorList<Guide> impl = new GuideCreatorListImpl();
    impl.setGuides(guides);

    System.out.println("Serializing the given parameter to JSON");

    // Fails on the below lines w/ NPE
    AutoBean<GuideCreatorList> bean = beanFactory.create(GuideCreatorList.class, impl);
    String json = AutoBeanCodex.encode(bean).getPayload();
    System.out.println("guides as json: " + json);

誰かが私を正しい方向に向けるのを手伝ってくれますか? どうもありがとうございました。

サポートするクラスとインターフェースは次のとおりです。

public interface GuideCreatorFactory extends AutoBeanFactory {
  AutoBean<GuideCreator> createGuide();

  AutoBean<GuideCreatorList> createGuideList();
}


public interface GuideCreator {

  public String getText();

  public void setText(String text);

  public String getTitle();

  public void setTitle(String title);

}


public interface GuideCreatorList<T extends GuideCreator> {
  public List<T> getGuides();

  public void setGuides(List<T> guides);
}



class GuideCreatorListImpl implements GuideCreatorList<Guide> {
    private List<Guide> guides;

    public GuideCreatorListImpl() {

    }

    @Override
    public List<Guide> getGuides() {
      return guides;
    }

    @Override
    public void setGuides(List<Guide> guides) {
      this.guides = guides;
    }
    };

NPE は次のとおりです。

java.lang.NullPointerException
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl.doEncode(AutoBeanCodexImpl.java:558)
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl$ObjectCoder.encode(AutoBeanCodexImpl.java:321)
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl$CollectionCoder.encode(AutoBeanCodexImpl.java:163)
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl$PropertyGetter.encodeProperty(AutoBeanCodexImpl.java:413)
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl$PropertyGetter.visitReferenceProperty(AutoBeanCodexImpl.java:389)
    at com.google.web.bindery.autobean.shared.AutoBeanVisitor.visitCollectionProperty(AutoBeanVisitor.java:229)
    at com.google.web.bindery.autobean.vm.impl.ProxyAutoBean.traverseProperties(ProxyAutoBean.java:300)
    at com.google.web.bindery.autobean.shared.impl.AbstractAutoBean.traverse(AbstractAutoBean.java:166)
    at com.google.web.bindery.autobean.shared.impl.AbstractAutoBean.accept(AbstractAutoBean.java:101)
    at com.google.web.bindery.autobean.shared.impl.AutoBeanCodexImpl.doEncode(AutoBeanCodexImpl.java:558)
    at com.google.web.bindery.autobean.shared.AutoBeanCodex.encode(AutoBeanCodex.java:83)
    at com.districthp.core.ui.client.review.JsonSerializationText.testMyObject(JsonSerializationText.java:82)
    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.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    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:50)
    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)
4

1 に答える 1

11

残念ながら、これは既知の問題です: https://github.com/gwtproject/gwt/issues/6903

問題は、リストの項目がAutoBeans にラップされていないためAutoBeanUtils#getAutoBean、AutoBeanCodexImpl.ObjectCoder#encodeが返されるnullため、NPE がAutoBeanCodexImpl#doEncode.

AutoBean回避策として、リスト項目を実際の値をラップする sに置き換える必要があります。

于 2012-07-17T23:29:17.767 に答える