在每个请求上构造ViewScoped bean ...第99部分 [英] ViewScoped bean getting constructed on every request... part 99
问题描述
ARGH ...这似乎有一百个答案，但我还没有找到适合我的答案，所以我想我实际上会再问一次.这是我的情况:
ARGH... This seems to have a hundred answers and I haven't found one that works for me, so I guess I will actually ask it again. Here is my scenario:
从技术上讲，我的网站只有一个页面，其内容被换出了，而不是具有多个导航页面.起点是这个块:
My site technically has a single page whose contents get swapped out rather than having multiple pages that you navigate to. The starting point is this chunk:
<?xml version="1.0" encoding="UTF-8"?>
<f:view xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head />
<h:body>
<ui:include src="resourceInclude.xhtml" />
<ui:include src="main.xhtml" />
</h:body>
</f:view>
resourceInclude.xhtml包含我的css文件:
The resourceInclude.xhtml includes my css file:
<?xml version="1.0" encoding="UTF-8"?>
<ui:composition xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:outputStylesheet library="css" name="test.css" target="head" />
</ui:composition>
main.xhtml是视图:
And main.xhtml is the view:
<?xml version="1.0" encoding="UTF-8"?>
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html">
<h:panelGroup styleClass="test-container" layout="block">
<h:form id="main-form">
<h:panelGroup styleClass="test-header" layout="block">
<h:panelGroup styleClass="navigation" layout="block">
<ul>
<li><h:commandLink action="#{viewSelector.setModeHome}">
<h:outputText value="Home" />
</h:commandLink></li>
<li><h:commandLink action="#{viewSelector.setModeReports}">
<h:outputText value="ASAP Reports" />
</h:commandLink></li>
<li><h:commandLink action="#{viewSelector.setModeSupport}">
<h:outputText value="Technical Support" />
</h:commandLink></li>
<li><h:commandLink action="#{viewSelector.setModeHelp}">
<h:outputText value="Help" />
</h:commandLink></li>
</ul>
</h:panelGroup>
</h:panelGroup>
<h:panelGroup styleClass="test-content" layout="block">
<ui:include src="#{viewSelector.modeName}-view.xhtml" />
</h:panelGroup>
<h:panelGroup styleClass="test-footer" layout="block">
<h:messages />
</h:panelGroup>
</h:form>
</h:panelGroup>
</ui:composition>
它由三个h:panelGroup组成.第一个是四个常规导航链接的集合，每个链接更改viewSelector.modeName值，该值用于将内容包含在第二个h:panelGroup中，从而包括了<ui:include src="#{viewSelector.modeName}-view.xhtml" />.在本示例中，我已经将其剥离下来，因此每个视图基本上都是这样:
It consists of three h:panelGroups. The first is a set of four general navigation links, each link changes the viewSelector.modeName value which is used to include the contents in the second h:panelGroup thusly <ui:include src="#{viewSelector.modeName}-view.xhtml" />. I have stripped this down for this example so each view is basically this:
<?xml version="1.0" encoding="UTF-8"?>
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html">
<h:panelGroup styleClass="test-home-view">
<p>home</p>
</h:panelGroup>
</ui:composition>
第三个h:panelGroup是所有消息的页脚，用于调试出问题所在.
The third h:panelGroup is a footer for all the messages to debug what is going wrong.
无论如何，每次我单击其中一个导航链接时，都会调用viewSelector bean的构造函数.这是我的viewSelector bean的样子:
Anyway, every time I click one of the navigation links, the constructor of the viewSelector bean gets called. This is what my viewSelector bean looks like:
package org.mitre.asias.aires.controller;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import org.apache.log4j.Logger;
@ManagedBean( name="viewSelector" )
@ViewScoped
public class ViewSelector {
protected static Logger log = Logger.getLogger( ViewSelector.class );
private Mode mode = Mode.HOME;
public static final String PORTLET_NAME = "Test";
public static enum Mode {
HOME(1, "home"),
REPORTS(2, "reports"),
SUPPORT(3, "support"),
HELP(4, "help");
private int value;
private String name;
private Mode( int value, String name ) {
this.value = value;
this.name = name;
}
public int getValue() {
return value;
}
public String getName() {
return name;
}
}
public ViewSelector() {
log.trace( "constructing new ViewSelector" );
}
public Mode getMode() {
log.trace( "getting mode" );
return mode;
}
public String getModeName() {
log.debug( "in getmodename" );
return getMode().getName();
}
public String getPortletName() {
return PORTLET_NAME;
}
public boolean isModeReports() {
return getMode() == Mode.REPORTS;
}
public void setMode( Mode mode ) {
this.mode = mode;
}
public void setModeHelp() {
setMode( Mode.HELP );
}
public void setModeHome() {
setMode( mode = Mode.HOME );
}
public void setModeReports() {
setMode( mode = Mode.REPORTS );
}
public void setModeSupport() {
setMode( mode = Mode.SUPPORT );
}
}
我知道我必须以错误的方式进行操作，否则我就缺少JSF的工作重点.有输入吗?
I know I must be doing something the wrong way, or else I missing something central as to how JSF works. Any Input?
推荐答案
<ui:include src>中的EL引起了这种情况.
The EL in <ui:include src> is causing that.
如果根据
If disabling the partial state saving in web.xml as per issue 1492 is not an option,
<context-param>
<param-name>javax.faces.PARTIAL_STATE_SAVING</param-name>
<param-value>true</param-value>
</context-param>
然后您需要更换
<ui:include src="#{viewSelector.modeName}-view.xhtml" />
通过类似的方式
<h:panelGroup rendered="#{viewSelector.mode == 'HOME'}">
<ui:include src="home-view.xhtml" />
</h:panelGroup>
<h:panelGroup rendered="#{viewSelector.mode == 'REPORTS'}">
<ui:include src="reports-view.xhtml" />
</h:panelGroup>
<h:panelGroup rendered="#{viewSelector.mode == 'SUPPORT'}">
<ui:include src="support-view.xhtml" />
</h:panelGroup>
<h:panelGroup rendered="#{viewSelector.mode == 'HELP'}">
<ui:include src="help-view.xhtml" />
</h:panelGroup>
类似的问题至少已经被问过一次了:)
A similar question has at least been asked once before :)
这篇关于在每个请求上构造ViewScoped bean ...第99部分的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
