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JSF教程 – JSF条件导航示例
使用托管bean，我们可以基于条件控制导航。
例如，以下代码显示如何为不同的pageId值返回不同的页面名称。
@ManagedBean(name = "navigationController", eager = true)
@RequestScoped
public class NavigationController implements Serializable {
//read value from request parameter pageId
@ManagedProperty(value="#{param.pageId}")
private String pageId;
//if pageId is 1 show page1.xhtml,
//if pageId is 2 show page2.xhtml
//else show default.xhtml
public String showPage(){
if(pageId == null){
return "default";
}
if(pageId.equals("1")){
return "page1";
}else if(pageId.equals("2")){
return "page2";
}else{
return "default";
}
}
}
在JSF UI组件中将pageId作为请求参数。
<h:form>
<h:commandLink action="#{navigationController.showPage}" value="Page1">
<f:param name="pageId" value="1" />
</h:commandLink>
<h:commandLink action="#{navigationController.showPage}" value="Page2">
<f:param name="pageId" value="2" />
</h:commandLink>
<h:commandLink action="#{navigationController.showPage}" value="Home">
<f:param name="pageId" value="3" />
</h:commandLink>
</h:form>
这里点击“Page1″按钮
JSF将创建一个参数为pageId = 1的请求。然后，JSF将这个参数传递给navigationController的managed属性pageId。
之后， navigationController.showPage()被调用，将检查pageId后返回view作为page1 。
JSF然后将视图名称 page1 解析为 page1.xhtml 扩展名，并在当前目录中找到相应的视图文件 page1.xhtml 。
例子
以下代码来自register.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:body>
<h2>This is resgister.xhtml</h2>
</h:body>
</html>
以下代码来自ordermore.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:body>
<h2>This is ordermore.xhtml</h2>
</h:body>
</html>
以下代码来自start.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:body>
<h2>This is start.xhtml</h2>
<h:form>
<h:commandButton action="payment" value="Payment" />
</h:form>
</h:body>
</html>
下面的代码来自UserBean.java。
package cn.w3cschool.common;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import java.io.Serializable;
@ManagedBean
@SessionScoped
public class UserBean implements Serializable {
private static final long serialVersionUID = 1L;
public boolean registerCompleted = true;
public int orderQty = 99;
public int getOrderQty() {
return orderQty;
}
public void setOrderQty(int orderQty) {
this.orderQty = orderQty;
}
public boolean isRegisterCompleted() {
return registerCompleted;
}
public void setRegisterCompleted(boolean registerCompleted) {
this.registerCompleted = registerCompleted;
}
}
以下代码来自payment.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:body>
<h2>This is payment.xhtml</h2>
</h:body>
</html>
下载 Conditional-Navigation.zip
运行
将生成的WAR文件从目标文件夹复制到Tomcat部署文件夹，并运行Tomcat-Install-folder/bin/startup.bat。
Tomcat完成启动后，在浏览器地址栏中键入以下URL。
http://localhost:8080/simple-webapp/start.xhtml
