Struts2 OGNL表达式
1、index.jsp
<body> 访问属性 <a href="ognl.action?username=u&password=p">ognl</a> </body>
<struts> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <constant name="struts.devMode" value="true" /> <constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant> <include file="/com/wxh/action/ognl.xml"/> </struts>
3.ognl.xml
<struts> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <constant name="struts.devMode" value="true" /> <package name="ognl" extends="struts-default"> <action name="ognl" class="com.wxh.action.OgnlAction"> <result>/ognl.jsp</result> </action> <action name="test" class="com.wxh.action.TestAction"> <result type="chain">ognl</result> </action> </package> </struts>
4.ognl.jsp
<body>
<ol>
<li>访问值栈中的action的普通属性:username=<s:property value="username"/></li>
<li>访问值栈中的对象的普通属性(get set 方法):<s:property value="user.age"/>|</li>
<li>访问值栈中的对象的普通属性（get set 方法）:<s:property value="cat.friend.name"/></li>
<li>访问值栈中的对象的普通方法：<s:property value="password.length()"/></li>
<li>访问值栈中的对象的普通方法：<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.wxh.action.S@s()"/></li>
<li>访问静态属性：<s:property value="@com.wxh.action.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.wxh.action.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中的某个元素:<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}.{age}"/></li>
<li>投影:<s:property value="users.{^#this.age>1}.{age}"/></li>
<li>投影:<s:property value="users.{$#this.age>1}.{age}"/></li>
<li>投影:<s:property value="users.{$#this.age>1}.{age}==null"/></li>
<hr/>
<li>[]:<s:property value="[0].username"/></li>
</ol>
<s:debug></s:debug>
</body>
5.OgnlAction.java
package com.wxh.action;
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 static final long serialVersionUID = 1L;
private String password;
private String username;
private User user;
private Cat cat;
private List<User> users=new ArrayList<User>();
private Set<Dog> dogs=new HashSet<Dog>();
private Map<String,Dog> dogMap=new HashMap<String,Dog>();
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 List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
public Set<Dog> getDogs() {
return dogs;
}
public void setDogs(Set<Dog> dogs) {
this.dogs = dogs;
}
public Map<String, Dog> getDogMap() {
return dogMap;
}
public void setDogMap(Map<String, Dog> dogMap) {
this.dogMap = dogMap;
}
public String m(){
return "hello";
}
public Cat getCat() {
return cat;
}
public void setCat(Cat cat) {
this.cat = cat;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String execute(){
return SUCCESS;
}
}
6.Cat.java
package com.wxh.action;
public class Cat {
private Dog friend;
public Dog getFriend() {
return friend;
}
public void setFriend(Dog friend) {
this.friend = friend;
}
public String miaomiao(){
return "miaomiao";
}
}
7.Dog.java
package com.wxh.action;
public class Dog {
public Dog(){
}
public Dog(String anme){
super();
this.name=name;
}
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String toString(){
return "dog:"+name;
}
}
8.S.java
package com.wxh.action;
public class S {
public static String STR="STATIC STRING";
public static String s(){
return "static method";
}
}
9.User.java
package com.wxh.action;
public class User {
private int age;
public User(){
System.out.println("user.constructor!");
}
public User(int age){
super();
this.age=age;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String toString(){
return "user"+age;
}
}
思考：在做一些实验的时候某些功能并没有展现。