Oracle ADF 意外的空指针异常在单独的线程中访问视图对象时

Question

我在 adf 中有一个处理请求的网络服务，我使用来自 jar 的方法运行通过视图对象迭代器等等。

在处理请求时，我从上述 jar 中调用一个方法，该方法初始化一个单独的线程，该线程在该单独的线程中操作和比较来自视图对象的行，

我收到如下随机异常：

## Detail 0 ##

java.lang.NullPointerException at oracle.jbo.server.ViewRowSetIteratorImpl.initViewRowSetIteratorImpl(ViewRowSetIteratorImpl.java:227) at oracle.jbo.server.ViewRowSetIteratorImpl.(ViewRowSetIteratorImpl.java:176) at oracle.jbo.server.ViewRowSetImpl.createNewRowSetIterator(ViewRowSetImpl.java:1434) at oracle.jbo.server.ViewRowSetImpl.createViewRowSetIterator(ViewRowSetImpl.java:1485) at oracle.jbo.server.ViewRowSetImpl.getDefaultRowSetIterator(ViewRowSetImpl.java:1704) at oracle.jbo.server.ViewRowSetImpl.setRangeSize(ViewRowSetImpl.java:2936) at oracle.jbo.server.ViewObjectImpl.doCreateViewLinkAccessorRS(ViewObjectImpl.java:16080) at oracle.jbo.server.ViewObjectImpl.createViewLinkAccessorRS(ViewObjectImpl.java:16171) at oracle.jbo.server.AssociationDefImpl.get(AssociationDefImpl.java:472) at oracle.jbo.server.ViewAttributeDefImpl.get(ViewAttributeDefImpl.java:949) at oracle.jbo.server.ViewRowStorage.getViewLinkAccessorResult(ViewRowStorage.java:1528) at oracle.jbo.server.ViewRowStorage.getAttributeInternal(ViewRowStorage.java:1827) at oracle.jbo.server.ViewRowImpl.getAttributeValue(ViewRowImpl.java:1923) at oracle.jbo.server.ViewRowImpl.getAttributeInternal(ViewRowImpl.java:866)

和

## Detail 0 ##

java.lang.NullPointerException at oracle.jbo.server.ViewRowImpl.getUseViewLogicGroupDef(ViewRowImpl.java:6078) at oracle.jbo.server.ViewRowStorage.getViewAttributeDef(ViewRowStorage.java:1432) at oracle.jbo.server.ViewRowStorage.getAttributeInternal(ViewRowStorage.java:1778) at oracle.jbo.server.ViewRowImpl.getAttributeValue(ViewRowImpl.java:1923) at oracle.jbo.server.ViewRowImpl.getAttributeInternal(ViewRowImpl.java:866)

和

Caused by: java.lang.NullPointerException at oracle.jbo.server.ViewRowSetIteratorImpl.initViewRowSetIteratorImpl(ViewRowSetIteratorImpl.java:227) at oracle.jbo.server.ViewRowSetIteratorImpl.(ViewRowSetIteratorImpl.java:176) at oracle.jbo.server.ViewRowSetImpl.createNewRowSetIterator(ViewRowSetImpl.java:1434) at oracle.jbo.server.ViewRowSetImpl.createViewRowSetIterator(ViewRowSetImpl.java:1485) at oracle.jbo.server.ViewRowSetImpl.getDefaultRowSetIterator(ViewRowSetImpl.java:1704) at oracle.jbo.server.ViewRowSetImpl.setRangeSize(ViewRowSetImpl.java:2936) at oracle.jbo.server.ViewObjectImpl.doCreateViewLinkAccessorRS(ViewObjectImpl.java:16080) at oracle.jbo.server.ViewObjectImpl.createViewLinkAccessorRS(ViewObjectImpl.java:16171) at oracle.jbo.server.AssociationDefImpl.get(AssociationDefImpl.java:472) at oracle.jbo.server.ViewAttributeDefImpl.get(ViewAttributeDefImpl.java:949) at oracle.jbo.server.ViewRowStorage.getViewLinkAccessorResult(ViewRowStorage.java:1528) at oracle.jbo.server.ViewRowStorage.getAttributeInternal(ViewRowStorage.java:1827) at oracle.jbo.server.ViewRowImpl.getAttributeValue(ViewRowImpl.java:1923) at oracle.jbo.server.ViewRowImpl.getAttributeInternal(ViewRowImpl.java:866)

在没有 jar 的情况下运行使用相同的方法（与 jar 中的代码相同，但作为同一项目的一部分），它执行得非常好。

你能告诉我为什么会引发 NullPointerException 吗？谢谢

Answer 1

您不能在线程内使用业务组件（ViewObject、Entities...等）。

没有上下文（无法初始化 FacesContext）。因此您必须将 ApplicationModule 作为参数传递给您的方法。但是处理起来会花费很多时间

因此，访问数据的最佳方法是将 CallableStatments PreparedStatments 与 Java 数据源连接一起使用。

Oracle ADF 意外的空指针异常在单独的线程中访问视图对象时

Oracle ADF Unexpected Null Pointer Exception When accessing view objects in a seperate thread

multithreading

nullpointerexception

oracle-adf