使用PhaseListener 来打印JSF组件树 (示例)
使用PhaseListener 来打印JSF组件树 (示例)作者: cschalk http://jroller.com/page/cschalk?entry=a_jsf_phaselistener_to_print
翻译: icess http://blog.matrix.org.cn/page/icess
你是否想知道在你的页面中到底有什么标签在组件树中.
我也想知道,所以我写了一个简单的 PhaseListener,用她把组件树输出到控制台.
使用的算法是递归打印组件树.
下面是代码:
package componentstuff;import java.util.ArrayList;import java.util.List;import javax.faces.component.UIComponent;import javax.faces.context.FacesContext;import javax.faces.event.PhaseEvent;import javax.faces.event.PhaseId;import javax.faces.event.PhaseListener;public class PrintComponentTree implements PhaseListener {public PrintComponentTree() {}public int indent = 0;public static final int INDENTSIZE = 2;public void beforePhase(PhaseEvent PhaseEvent) {}public void afterPhase(PhaseEvent PhaseEvent) { System.out.println(""); System.out.println("(Rendering Component Tree)"); printComponentTree(FacesContext.getCurrentInstance().getViewRoot());}public PhaseId getPhaseId() { return PhaseId.RENDER_RESPONSE; } public void printComponentTree(UIComponent comp){ printComponentInfo(comp); List complist = (ArrayList)comp.getChildren(); if (complist.size()>0) indent++; for (int i = 0; i < complist.size(); i++) { UIComponent uicom = (UIComponent) complist.get(i); printComponentTree(uicom); if (i+1 == complist.size()) indent--; } }public void printComponentInfo(UIComponent comp){ if (comp.getId() == null){ System.out.println("UIViewRoot" + " " + "(" + comp.getClass().getName() + ")"); } else { printIndent(); System.out.println("|"); printIndent(); System.out.println(comp.getId() + " " + "(" + comp.getClass().getName() + ")"); } } public void printIndent(){ for (int i=0; i<indent; i++ ) for (int j=0;j<INDENTSIZE; j++) System.out.print(" "); }}
还有,不要忘了在 faces-config中注册listener..
<lifecycle>
<phase-listener>componentstuff.PrintComponentTree</phase-listener>
</lifecycle>
下面是一个示例输出:
06/03/03 17:26:39 (Rendering Component Tree)
06/03/03 17:26:39 UIViewRoot (javax.faces.component.UIViewRoot)
06/03/03 17:26:39 |
06/03/03 17:26:39 form1 (javax.faces.component.html.HtmlForm)
06/03/03 17:26:39 |
06/03/03 17:26:39 panelGrid1 (javax.faces.component.html.HtmlPanelGrid)
06/03/03 17:26:39 |
06/03/03 17:26:39 outputLabel1 (javax.faces.component.html.HtmlOutputLabel)
06/03/03 17:26:39 |
06/03/03 17:26:39 inputText1 (javax.faces.component.html.HtmlInputText)
06/03/03 17:26:39 |
06/03/03 17:26:39 outputLabel2 (javax.faces.component.html.HtmlOutputLabel)
06/03/03 17:26:39 |
06/03/03 17:26:39 inputSecret1 (javax.faces.component.html.HtmlInputSecret)
06/03/03 17:26:39 |
06/03/03 17:26:39 commandButton1 (javax.faces.component.html.HtmlCommandButton)
页:
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