Struts2获取表单数据并封装到实体类的方法

1.采用ActionContext对象的方式

public String execute() throws Exception {
        // 获取ActionContext对象
        ActionContext context = ActionContext.getContext();
        // 获取参数Map对象
        Map<String, Object> map = context.getParameters();
        // 遍历Map集合
        Set<String> set = map.keySet();
        for (String key : set) {
            // 表单value值是Object数组，因为存在表单中多值的情况
            Object[] values = (Object[]) map.get(key);
            System.out.println(Arrays.toString(values));
        }
        return NONE;
    }

2.采用ServletActionContext对象的方式

public String execute() throws Exception {
        // 通过ServletActionContext对象得到HttpServletRequest对象
        HttpServletRequest request = ServletActionContext.getRequest();
        // 取值
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String address = request.getParameter("address");
        // 创建User对象并复制进去
        return NONE;

3.采用接口注入的方式

public class TestAction3 extends ActionSupport implements ServletRequestAware {
    private HttpServletRequest request = null;
    public void setServletRequest(HttpServletRequest request) {
        // TODO Auto-generated method stub
        this.request = request;
    }

    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String address = request.getParameter("address");
        System.out.println(username + ":" + password + ":" + address);
        return NONE;
    }

4.采用属性封装

　　　表单数据

 <form action="${pageContext.request.contextPath }/form.action" method="post">
        用户名：<input type="text" name="username"/><br/>
        密　码：<input type="password" name="password"/><br/>
        地　址：<input type="text" name="address"/><br/>
        <input type="submit" value="提交"/>
    </form>

　　声明表单属性，并生成set方法

 　 private String username;
    private String password;
    private String address;

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

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

    public void setAddress(String address) {
        this.address = address;
    }

    public String execute() throws Exception {
        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
        user.setAddress(address);
        return NONE;
    }

5.模型驱动封装（重点）

public class DemoAction1 extends ActionSupport implements ModelDriven<User> {
    private User user = new User();

    public User getUser() {
        return user;
    }

    @Override
    public User getModel() {
        // TODO Auto-generated method stub
        return user;
    }

    public String execute() throws Exception {
        System.out.println(user);
        return NONE;
    }
}

6.表达式封装

　　表单数据，注意name属性值的写法，实体对象。属性名

 <form action="${pageContext.request.contextPath }/form.action" method="post">
        用户名：<input type="text" name="user.username"/><br/>
        密　码：<input type="password" name="user.password"/><br/>
        地　址：<input type="text" name="user.address"/><br/>
        <input type="submit" value="提交"/>
    </form>

　　代码，注意生成实体类的set和get方法

    private User user;

    public User getUser() {
        return user;
    }

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

    public String execute() throws Exception {
        System.out.println(user);
        return NONE;
    }

 7.List集合封装

      表单数据    [0]为list下标值

<form action="${pageContext.request.contextPath }/form5" method="post">
          用户名：<input type="text" name="list[0].username"/><br/>
          密　码：<input type="password" name="list[0].password"/><br/>
          年　龄：<input type="text" name="list[0].age"/><br/>
          地　址：<input type="text" name="list[0].address"/><br/>
          <input type="submit" value="提交"/>
      </form>

　　代码

    private List<User> list;

    public List<User> getList() {
        return list;
    }

    public void setList(List<User> list) {
        this.list = list;
    }

    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        System.out.println(list);
        return NONE;
    }

8.Map集合封装

　　页面   'one'为键

    <form action="${pageContext.request.contextPath }/form6" method="post">
          用户名：<input type="text" name="map['one'].username"/><br/>
          密　码：<input type="password" name="map['one'].password"/><br/>
          年　龄：<input type="text" name="map['one'].age"/><br/>
          地　址：<input type="text" name="map['one'].address"/><br/>
          <input type="submit" value="提交"/>
      </form>

　　代码

    private Map<String, User> map;
    
    public Map<String, User> getMap() {
        return map;
    }

    public void setMap(Map<String, User> map) {
        this.map = map;
    }

    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        System.out.println(map);
        return NONE;
    }