Struts2 页面获取参数 List,Set,Map 及调用函数和实例化对象

相应的action，在action中实例化了许多需要传递给客户端的参数

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

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

    private String password;

    private User user = new 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() {
        System.out.println(user.toString());
        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;
    }
}

服务区相关的实体类对象和工具类

public class Cat {
    
    private Dog friend;
    
    public Dog getFriend() {
        return friend;
    }

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

    public String miaomiao() {
        return "miaomiao";
    }
}
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;
    }
}
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;
    }
}
public class S {
    public static String STR = "STATIC STRING";
    
    public static String s() {
        return "static method";
    }
}

客户端页面获取参数

<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：@com.yao.action.ognl.S@s()   <s:property value="@com.yao.action.ognl.S@s()"/></li>
        <li>访问静态属性：@com.yao.action.ognl.S@STR   <s:property value="@com.yao.action.ognl.S@STR"/></li>
        <li>访问Math类的静态方法：@@max(2,3)    <s:property value="@@max(2,3)" /></li>
        <hr />
        
        <s:set name="user1" value="new com.yao.action.ognl.User(9)" scope="request"></s:set>
        <li>创建一个对象，访问对象:<s:property value="#request.user1.toString()"/>|${user1.age}<br></li>
        <li>访问普通类的构造方法：new com.yao.action.ognl.User(8)  <s:property  value="new com.yao.action.ognl.User(8)"  /></li>
        <hr />
        <li>访问List:<s:property value="users"/></li>
        <li>访问List中某个元素:<s:property value="users[1]"/></li>
        <li>访问List中元素某个属性的集合:<s:property value="users.{age}"/></li>
        <li>访问List中元素某个属性的集合中的特定值:<s:property value="users.{age}[0]"/> | <s:property value="users[0].age"/></li>
        <li>访问Set:<s:property value="dogs"/></li>
        <li>访问Map:<s:property value="dogMap"/></li>
        <li>访问Map中某个元素:<s:property value="dogMap.dog101"/> | <s:property value="dogMap['dog101']"/> | <s:property value="dogMap["dog101"]"/></li>
        <li>访问Map中所有的key:<s:property value="dogMap.keys"/></li>
        <li>访问Map中所有的value:<s:property value="dogMap.values"/></li>
        <li>访问容器的大小：<s:property value="dogs.size()"/> | <s:property value="dogMap.size()"/> | <s:property value="users.size"/> </li>
        <hr />
        <li>投影(过滤)：<s:property value="users.{?#this.age==1}[0]"/></li>
        <li>投影：<s:property value="users.{^#this.age>1}"/></li>
        <li>投影：<s:property value="users.{$#this.age>1}.{age}"/></li>
        <li>投影：<s:property value="users.{$#this.age>1}.{age} == null"/></li>
        <hr />
        <!-- 获取参数值 -->
        <li>[]:<s:property value="[0].username"/></li>
        <li>[]:<s:property value="[0].password"/></li>
    </ol>
    
    <s:debug></s:debug>
  </body>
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原文地址：https://www.cnblogs.com/songyao/p/4146829.html