Question

I’m using the struts2 tiles plugin (v2.2.3) and I’m having a problem using the I18nInterceptor with the ExecuteAndWaitInterceptor. Essentially when I add the execAndWait interceptor (see xml below) for some reason the localization no longer works and when I try to get localized text (e.g. TextProviderSupport.hasKey) I get a NullPointerException (see error) that I narrowed down to this code in LocalizedTextUtil…

public static String findText(Class aClass, String aTextName, Locale locale, String defaultMessage, Object[] args) {
    ValueStack valueStack = ActionContext.getContext().getValueStack();
    return findText(aClass, aTextName, locale, defaultMessage, args, valueStack);

}

… I’m assuming the getValueStack() is null for some reason, but I cannot figure out why. Any ideas?

Thanks,
Ryan

<pre><code>    
    java.lang.NullPointerException
      at com.opensymphony.xwork2.util.LocalizedTextUtil.findText(LocalizedTextUtil.java:359)
      at com.opensymphony.xwork2.TextProviderSupport.hasKey(TextProviderSupport.java:98)
      at com.opensymphony.xwork2.ActionSupport.hasKey(ActionSupport.java:96)
      at com.test.plus.PlusSupport.getCurrentLocale(PlusSupport.java:213)
      at com.test.plus.import.Test.action.TestAction.testMethod(TestAction.java:801)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452)
      at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291)
      at org.apache.struts2.interceptor.BackgroundProcess$1.run(BackgroundProcess.java:57)
      at java.lang.Thread.run(Unknown Source)
</code></pre>

Struts.xml

<action name="Test/m/testMethod" method="testMethod" class="com.test.plus.import.Test.action.TestAction">
    <result type="tiles">/WEB-INF/jsp/import/Test/testMethod.jsp</result>
    <result name="success" type="tiles">/WEB-INF/jsp/import/Test/testMethod.jsp</result>
    <result name="input" type="tiles">/WEB-INF/jsp/import/Test/testMethod.jsp</result>
    <result name="error" type="tiles">/WEB-INF/jsp/import/Test/testMethod.jsp</result>
    <result name="wait" type="tiles">/WEB-INF/jsp/import/execAndWait.jsp</result>
    <interceptor-ref name="plusStack"/>
    <interceptor-ref name="defaultStack"/>
    <interceptor-ref name="execAndWait">
      <param name="excludeMethods">input,back,cancel</param>
    </interceptor-ref>
</action>

Answer 1

From http://struts.apache.org/2.x/docs/execute-and-wait-interceptor.html

Important: Because the action will be running in a seperate thread, you can’t use ActionContext because it is a ThreadLocal. This means if you need to access, for example, session data, you need to implement SessionAware rather than calling ActionContext.getSession().