知识点：
servlet是单例的，Action是多例的，一次请求，创建一个Action的实例
结果页面分为全局和局部两类（局部优先级更高）
result标签： name : 默认succes type ：页面跳转类型 dispatcher 默认值，请求转发（action转发jsp） redirect 重定向（action重定向jsp） chain 转发（action转发action） redirectAction 重定向（action重定向action） stream struts2中提供文件下载的功能
代码如下
struts.xml
代码语言：javascript复制<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
<package name="demo1" extends="struts-default">
<!--全局结果页面-->
<global-results>
<result name="success">servlet1/demo2.jsp</result>
</global-results>
<action name="requestDemo1" class="com.jinke.servlet1.RequestDemo1"/>
<action name="requestDemo2" class="com.jinke.servlet1.RequestDemo2"/>
<action name="requestDemo3" class="com.jinke.servlet1.RequestDemo3"/>
<!--局部结果页面-->
<action name="requestDemo1" class="com.jinke.servlet1.RequestDemo1">
<result name="success">servlet1/demo2.jsp</result>
</action>
<action name="requestDemo2" class="com.jinke.servlet1.RequestDemo2">
<result name="success">servlet1/demo2.jsp</result>
</action>
<action name="requestDemo3" class="com.jinke.servlet1.RequestDemo3">
<result name="success">servlet1/demo2.jsp</result>
</action>
</package>
</struts>web.xml
代码语言：javascript复制<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>servlet1/demo1.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>demo1.jsp
代码语言：javascript复制<%--
Created by IntelliJ IDEA.
User: wanglei
Date: 2019/6/18
Time: 11:03
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>Struts2访问Servlet的API</h1>
<h3>方式一：完成解耦合的方式</h3>
<form action="${pageContext.request.contextPath}/requestDemo1.action" method="post">
姓名：<input type="text" name="name"><br/>
密码：<input type="password" name="password"><br/>
<input type="submit" value="提交"></form>
<h3>方式二：完成原生的方式访问</h3>
<form action="${pageContext.request.contextPath}/requestDemo2.action" method="post">
姓名：<input type="text" name="name"><br/>
密码：<input type="password" name="password"><br/>
<input type="submit" value="提交"></form>
<h3>方式三：接口注入的方式访问</h3>
<form action="${pageContext.request.contextPath}/requestDemo3.action" method="post">
姓名：<input type="text" name="name"><br/>
密码：<input type="password" name="password"><br/>
<input type="submit" value="提交"></form>
</body>
</html>demo2.jsp
代码语言：javascript复制<%--
Created by IntelliJ IDEA.
User: wanglei
Date: 2019/6/18
Time: 11:24
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>显示数据</h1>
${reqName}<br/>
${sessName}<br/>
${appName}<br/>
</body>
</html>action层
代码语言：javascript复制import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.dispatcher.HttpParameters;
/**
* 访问Servlet的API方式一：完全解耦合的方式
*/
public class RequestDemo1 extends ActionSupport {
@Override
public String execute() throws Exception {
//接收参数
//利用struts2中的对象ActionContext对象
ActionContext context = ActionContext.getContext();
//调用ActionContext中方法
HttpParameters map = context.getParameters();
// System.out.println(map);
//二.向域对象中存入数据
context.put("reqName", map);//相当于request.setAttribute()
context.getSession().put("sessName", map);//相当于session.setAttribute()
context.getApplication().put("appName", map);//相当于application.setAttribute()
return SUCCESS;
}
}import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.ServletActionContext;
import javax.servlet.http.HttpServletRequest;
import java.util.Map;
/**
* 访问Servlet的API方式二：采用原生的方式
*/
public class RequestDemo2 extends ActionSupport {
@Override
public String execute() throws Exception {
//一、接收数据
//直接获得request对象，通过ServletActionSupport
HttpServletRequest request = ServletActionContext.getRequest();
Map<String, String[]> map = request.getParameterMap();
System.out.println(map.toString());
//二、向域对象中保存数据
//向request中保存数据
request.setAttribute("reqName", map.toString());
//向session中保存数据
request.getSession().setAttribute("sessName", map.toString());
//向application中保存数据
ServletActionContext.getServletContext().setAttribute("appName", map.toString());
return SUCCESS;
}
}import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.util.ServletContextAware;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.util.Arrays;
import java.util.Map;
/**
* 访问Servlet的API方式三：接口注入的方式
*/
public class RequestDemo3 extends ActionSupport implements ServletRequestAware, ServletContextAware {
private HttpServletRequest request;
private ServletContext context;
@Override
public String execute() throws Exception {
//一、接收参数
//通过接口注入的方式获得request对象
Map<String, String[]> map = request.getParameterMap();
for (String key : map.keySet()) {
String[] value = map.get(key);
System.out.println(key " " Arrays.toString(value));
}
//二、向域对象中保存数据
//向request域中保存数据
request.setAttribute("reqName", map.toString());
//向session中保存数据
request.getSession().setAttribute("sessName", map.toString());
//向Application中保存数据
context.setAttribute("appName", map.toString());
return super.execute();
}
@Override
public void setServletRequest(HttpServletRequest httpServletRequest) {
this.request = httpServletRequest;
}
@Override
public void setServletContext(ServletContext servletContext) {
this.context = servletContext;
}
}结果
