Question

我在我的网络应用程序上使用JSF 1.2。在我的页面test.xhtml中，我有一个包含commandButton的表单：

<h:form>
  <h:commandButton action="#{myBean.myMethod}" value="Call my method" />
</h:form>

在java源码中，我的bean就是这样：

public class MyBean {
  public void myMethod() {
    System.out.println("my method called");
  }
}

当我显示我的页面test.xhtml时，第一次单击我的命令按钮时，该动作被很好地调用。页面刷新。然后，我尝试单击命令按钮，不会调用该操作。就好像JSF生命周期直接进入RENDER_RESPONSE阶段而不调用INVOKE_APPLICATION阶段。

刷新页面，然后单击时，可以很好地调用该操作。因此，该动作在两次上被调用一次。

为了尝试理解，我非常简单地添加了一个阶段监听器：

public class MyPhaseListener implements PhaseListener{

public PhaseId getPhaseId() {
    return PhaseId.ANY_PHASE;
}

public void beforePhase(PhaseEvent event) {
    System.out.println("START PHASE " + event.getPhaseId());
}

public void afterPhase(PhaseEvent event) {
    System.out.println("END PHASE " + event.getPhaseId());
}}

当我运行测试时点击我的页面，我有以下输出：

START PHASE RESTORE_VIEW 1
END PHASE RESTORE_VIEW 1
START PHASE APPLY_REQUEST_VALUES 2
END PHASE APPLY_REQUEST_VALUES 2
START PHASE PROCESS_VALIDATIONS 3
END PHASE PROCESS_VALIDATIONS 3
START PHASE UPDATE_MODEL_VALUES 4
END PHASE UPDATE_MODEL_VALUES 4
START PHASE INVOKE_APPLICATION 5
my method called
END PHASE INVOKE_APPLICATION 5
START PHASE RENDER_RESPONSE 6
END PHASE RENDER_RESPONSE 6

START PHASE RESTORE_VIEW 1
END PHASE RESTORE_VIEW 1
START PHASE RENDER_RESPONSE 6
END PHASE RENDER_RESPONSE 6

START PHASE RESTORE_VIEW 1
END PHASE RESTORE_VIEW 1
START PHASE APPLY_REQUEST_VALUES 2
END PHASE APPLY_REQUEST_VALUES 2
START PHASE PROCESS_VALIDATIONS 3
END PHASE PROCESS_VALIDATIONS 3
START PHASE UPDATE_MODEL_VALUES 4
END PHASE UPDATE_MODEL_VALUES 4
START PHASE INVOKE_APPLICATION 5
my method called
END PHASE INVOKE_APPLICATION 5
START PHASE RENDER_RESPONSE 6
END PHASE RENDER_RESPONSE 6

START PHASE RESTORE_VIEW 1
END PHASE RESTORE_VIEW 1
START PHASE RENDER_RESPONSE 6
END PHASE RENDER_RESPONSE 6

通过使用PhaseListener，我清楚地看到，在每次生命周期的第二次调用中，RESTORE_VIEW阶段直接进入RENDER_RESPONSE而不需要我在生命周期中的操作。

有人会想并避免这种情况并且每次都为该页面执行生命周期吗？或者是每次单击命令按钮时执行操作的解决方案？

就像你告诉我的那样，我在打印件上添加了一些调试信息，比如UIViewRoot对象和会话ID。行动顺序现在提供以下信息：

START PHASE RESTORE_VIEW 1
UIViewRoot :null
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RESTORE_VIEW 1
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE APPLY_REQUEST_VALUES 2
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE APPLY_REQUEST_VALUES 2
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE PROCESS_VALIDATIONS 3
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE PROCESS_VALIDATIONS 3
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE UPDATE_MODEL_VALUES 4
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE UPDATE_MODEL_VALUES 4
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE INVOKE_APPLICATION 5
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
my method called
END PHASE INVOKE_APPLICATION 5
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cbcb4
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7


START PHASE RESTORE_VIEW 1
UIViewRoot :null
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RESTORE_VIEW 1
UIViewRoot :javax.faces.component.UIViewRoot@7cbaea
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cbaea
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cbaea
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7


START PHASE RESTORE_VIEW 1
UIViewRoot :null
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RESTORE_VIEW 1
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE APPLY_REQUEST_VALUES 2
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE APPLY_REQUEST_VALUES 2
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE PROCESS_VALIDATIONS 3
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE PROCESS_VALIDATIONS 3
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE UPDATE_MODEL_VALUES 4
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE UPDATE_MODEL_VALUES 4
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE INVOKE_APPLICATION 5
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
my method called
END PHASE INVOKE_APPLICATION 5
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7ccfa1
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7


START PHASE RESTORE_VIEW 1
UIViewRoot :null
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RESTORE_VIEW 1
UIViewRoot :javax.faces.component.UIViewRoot@7cac2f
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
START PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cac2f
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7
END PHASE RENDER_RESPONSE 6
UIViewRoot :javax.faces.component.UIViewRoot@7cac2f
Session ID : 8385AC329B4C75AB4FBCA2CE1FBDFDC7

每个呼叫序列之间的会话始终相同。所以，我不认为这是UIViewRoot的问题。我还可以采取其他措施来测试这个问题吗？

西尔。

Answer 1

如果您还没有阅读此博客文章，则应该：http://balusc.blogspot.com/2006/09/debug-jsf-lifecycle.html

看起来您正在丢失会话，因为UIViewRoot不存在，因此没有UIViewRoot可以恢复。

h：两次调用只调用一次commandButton动作

1 个答案: