Struts笔记2

Struts2-配置文件result元素

作用：为动作指定结果视图

name属性：逻辑视图的名称，对应着动作方法的返回值。默认值是success

type属性:结果类型，指的就是用什么方式转到定义的页面，默认是dispatcher

result中type的取值有四种类型

result元素 转发与重定向

dispatcher:是转发到一个页面(jsp)

chain:是转发到一个action

redirect：重定向一个页面

redirectAction:重定向到另一个action

自定义结果类型

上面的重定向，转发都是结果类型

结果类型就是一个类，这些类都是些com.opensymphony.xwork2.Result接口,或者继承自接口的实现类org.apache.struts2.dispatcher.StrutsResultSupport

这些类都有一个doExecute方法，用于执行结果视图，struts的内部实现就是Servlet

自定义验证码结果类型

package com.gyf.web.result;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.StrutsResultSupport;

import com.opensymphony.xwork2.ActionInvocation;

import cn.dsna.util.images.ValidateCode;

public class CAPTCHAResult extends StrutsResultSupport{
    private int width;
    private int height;
    @Override
    protected void doExecute(String arg0, ActionInvocation arg1) throws Exception {
        //生成验证码
        //创建一个验证码对象
        ValidateCode code = new ValidateCode(width,height,4,6);
        //获取response对象，因为要返回给客户端
        HttpServletResponse response = ServletActionContext.getResponse();
        code.write(response.getOutputStream());//write方法可以把图片写回给客户端，但是需要一个输出流
    }
    public int getHeight() {
        return height;
    }
    public int getWidth() {
        return width;
    }
    public void setWidth(int width) {
        this.width = width;
    }
    public void setHeight(int height) {
        this.height = height;
    }
    
    
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
    <!-- 配置开发模式 -->
   <constant name="struts.devMode" value="true"></constant>
   
   
   <package name="p1" extends="struts-default" namespace="/n1">     
        <!--声明一个结果类型  -->
        <result-types>
            <result-type  name="captcha" class="com.gyf.web.result.CAPTCHAResult"></result-type>
        </result-types> 
        <!--配置action -->
        <action name="checkcode">
            <result type="captcha">
                <param name="width">150</param>
                <param name="height">60</param>
             </result>
        </action>
   </package>
</struts>

result元素-全局视图和局部视图

Struts2-动作类中的servlet api 访问讲解

第一种方式

package com.gyf.web.action;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class TestAction extends ActionSupport{
    public String test() {
        //获取servlet 的api方式
        //第一种方式：通过ServletActionContext
        //response
        HttpServletResponse response = ServletActionContext.getResponse();
        //request
        HttpServletRequest request = ServletActionContext.getRequest();
        //session
        HttpSession session = request.getSession();
        //application[ServletContext]
        ServletContext application = ServletActionContext.getServletContext();
        
        
        System.out.println(request);
        System.out.println(response);
        System.out.println(session);
        System.out.println(application);
        
        
        //NONE相当于不用跳转页面，也就是相当于不用找result标签,
        return NONE;
    }
}

第二种方式

package com.gyf.web.action;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.util.ServletContextAware;

import com.opensymphony.xwork2.ActionSupport;

public class TestAction2 extends ActionSupport implements ServletRequestAware,ServletResponseAware,ServletContextAware{
    HttpServletResponse response;
    HttpServletRequest request;
    ServletContext application;
    public String test() {
        //第二种方式，通过实现接口，让Struts自动注入
        System.out.println(request);
        System.out.println(response);
        System.out.println(application);
        
        
        //NONE相当于不用跳转页面，也就是相当于不用找result标签,
        return NONE;
    }
    @Override
    public void setServletResponse(HttpServletResponse response) {
        this.response=response;
        
    }
    @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request=request;
        
    }
    @Override
    public void setServletContext(ServletContext application) {
        this.application=application;
        
    }
}

Action接收请求参数

通过Servlet和Action的属性set方法注入获取参数

package com.gyf.web.action;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{
    //第二种方式通过属性的set注入
    private String username;
    private String password;
    
    public String login() {
        //第一种方式：通过ServletActionContext
        //request
//      HttpServletRequest request = ServletActionContext.getRequest();
//      String username = request.getParameter("username");
//      String password = request.getParameter("password");
        
        System.out.println(username);
        System.out.println(password);
        //NONE相当于不用跳转页面，也就是相当于不用找result标签,
        return NONE;
    }
    
    public String getUsername() {
        return username;
    }

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

    public String getPassword() {
        return password;
    }

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

    
}

第三种方式通过Action的属性的set模型的形式注入

第四种方式通过模型驱动在action里实现一个模型驱动接口

实现步骤：

在action里实现一个模型驱动接口

提供一个模型属性，并一定要赋值

实现原理：是因为有个模型驱动的拦截器在处理，ModelDrivenIngetrceptor，处理过程中给User赋予值

package com.gyf.web.model;

public class User {
    private String username;
    private String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User [username=" + username + ", password=" + password + "]";
    }
    
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<!-- 第四种方式 -->
<form action="${pageContext.request.contextPath}/login.action">
    用户名<input type="text" name="username"><br>
    密码<input type="password" name="password"><br>
    <input type="submit" name="登录">
</form>

<!-- 第三种方式 -->
<!-- 
    <form action="${pageContext.request.contextPath}/login.action">
    用户名<input type="text" name="user.username"><br>
    密码<input type="password" name="user.password"><br>
    <input type="submit" name="登录">
</form>
 -->
</body>
</html>

package com.gyf.web.action;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.gyf.web.model.User;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;

public class LoginAction extends ActionSupport implements ModelDriven<User>{

    public String login() {
        
        System.out.println(user);
        
        return NONE;    
    }   
    private User user = new User();
    @Override
    public User getModel() {
        
        return user;
    }
    
}