ongl表达式用法

struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />
    <constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant>
<include file="/com/bjsxt/struts2/ognl/ognl.xml"/>
</struts>


ognl.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
        "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <package name="ognl" extends="struts-default">

        <action name="ognl" class="com.bjsxt.struts2.ognl.OgnlAction">
            <result>/ognl.jsp</result>
        </action>
        <action name="test" class="com.bjsxt.struts2.ognl.TestAction">
            <result type="chain">ognl</result>
        </action>

    </package>
</struts>


OgnlAction.java
package com.bjsxt.struts2.ognl;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.opensymphony.xwork2.ActionSupport;

public class OgnlAction extends ActionSupport {
private Cat cat;
private Map<String, Dog> dogMap = new HashMap<String, Dog>();

private Set<Dog> dogs = new HashSet<Dog>();

private String password;

private User user;
private String username;

private List<User> users = new ArrayList<User>();

public OgnlAction() {
users.add(new User(1));
users.add(new User(2));
users.add(new User(3));

dogs.add(new Dog("dog1"));
dogs.add(new Dog("dog2"));
dogs.add(new Dog("dog3"));

dogMap.put("dog100", new Dog("dog100"));
dogMap.put("dog101", new Dog("dog101"));
dogMap.put("dog102", new Dog("dog102"));

}

public String execute() {
return SUCCESS;
}

public Cat getCat() {
return cat;
}

public Map<String, Dog> getDogMap() {
return dogMap;
}

public Set<Dog> getDogs() {
return dogs;
}

public String getPassword() {
return password;
}

public User getUser() {
return user;
}

public String getUsername() {
return username;
}

public List<User> getUsers() {
return users;
}

public String m() {
return "hello";
}

public void setCat(Cat cat) {
this.cat = cat;
}

public void setDogMap(Map<String, Dog> dogMap) {
this.dogMap = dogMap;
}

public void setDogs(Set<Dog> dogs) {
this.dogs = dogs;
}

public void setPassword(String password) {
this.password = password;
}

public void setUser(User user) {
this.user = user;
}

public void setUsername(String username) {
this.username = username;
}

public void setUsers(List<User> users) {
this.users = users;
}
}



Cat.java
package com.bjsxt.struts2.ognl;

public class Cat {

private Dog friend;

public Dog getFriend() {
return friend;
}

public void setFriend(Dog friend) {
this.friend = friend;
}

public String miaomiao() {
return "miaomiao";
}
}



Dog.java

package com.bjsxt.struts2.ognl;

public class Dog {

private String name;

public Dog() {

}

public Dog(String name) {
super();
this.name = name;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public String toString() {
return "dog: " + name;
}
}



User.java

package com.bjsxt.struts2.ognl;

public class User {
private int age = 8;

public User() {

}

public User(int age) {
super();
this.age = age;
}


public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

@Override
public String toString() {
return "user" + age;
}
}



S.java

package com.bjsxt.struts2.ognl;

public class S {
public static String STR = "STATIC STRING";

public static String s() {
return "static method";
}
}



TestAction.java
package com.bjsxt.struts2.ognl;

import com.opensymphony.xwork2.ActionSupport;

public class TestAction extends ActionSupport {

@Override
public String execute() throws Exception {
return super.execute();
}

}



ognl.jsp
<?xml version="1.0" encoding="GB18030" ?>
<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030" />
<title>OGNL表达式语言学习</title>
</head>
<body>
<ol>
<li>访问值栈中的action的普通属性: username = <s:property value="username"/> </li>
<li>访问值栈中对象的普通属性(get set方法)：<s:property value="user.age"/> | <s:property value="user['age']"/> | <s:property value="user[\"age\"]"/> | wrong: <%--<s:property value="user[age]"/>--%></li>
<li>访问值栈中对象的普通属性(get set方法): <s:property value="cat.friend.name"/></li>
<li>访问值栈中对象的普通方法：<s:property value="password.length()"/></li>
<li>访问值栈中对象的普通方法：<s:property value="cat.miaomiao()" /></li>
<li>访问值栈中action的普通方法：<s:property value="m()" /></li>
<hr />
<li>访问静态方法：<s:property value="@com.bjsxt.struts2.ognl.S@s()"/></li><!-- 类名@方法名 -->
<li>访问静态属性：<s:property value="@com.bjsxt.struts2.ognl.S@STR"/></li>
<li>访问Math类的静态方法：<s:property value="@@max(2,3)" /></li>
<hr />
<li>访问普通类的构造方法：<s:property value="new com.bjsxt.struts2.ognl.User(8)"/></li>
<hr />
<li>访问List:<s:property value="users"/></li>
<li>访问List中某个元素:<s:property value="users[1]"/></li>
<li>访问List中元素某个属性的集合:<s:property value="users.{age}"/></li>
<li>访问List中元素某个属性的集合中的特定值:<s:property value="users.{age}[0]"/> | <s:property value="users[0].age"/></li>
<li>访问Set:<s:property value="dogs"/></li>
<li>访问Set中某个元素:<s:property value="dogs[1]"/></li>
<li>访问Map:<s:property value="dogMap"/></li>
<li>访问Map中某个元素:<s:property value="dogMap.dog101"/> | <s:property value="dogMap['dog101']"/> | <s:property value="dogMap[\"dog101\"]"/></li>
<li>访问Map中所有的key:<s:property value="dogMap.keys"/></li>
<li>访问Map中所有的value:<s:property value="dogMap.values"/></li>
<li>访问容器的大小：<s:property value="dogMap.size()"/> | <s:property value="users.size"/> </li>
<hr />
<li>投影(过滤)：<s:property value="users.{?#this.age==1}[0]"/></li>
<li>投影：<s:property value="users.{^#this.age>1}.{age}"/></li>
<li>投影：<s:property value="users.{$#this.age>1}.{age}"/></li>
<li>投影：<s:property value="users.{$#this.age>1}.{age} == null"/></li>
<hr />
<li>[]:<s:property value="[0].username"/></li><!-- 访问ongl的action -->

</ol>

<s:debug></s:debug>
</body>
</html>


index.jsp
<?xml version="1.0" encoding="GB18030" ?>
<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%
String contextPath = request.getContextPath();
%>
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030" />
<title>Insert title here</title>
</head>
<body>
访问属性
<a href="<%=contextPath %>/ognl.action?username=u&password=p">ognl</a>
</body>
</html>