Structs复习访问web元素

2022-01-03 20:38:25

Structs帮我们在action和http里建立了联系

主要有四种方式我们主要用第二种（IOC 依赖容器注入）

Jar包

web.XML

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

    xmlns="http://java.sun.com/xml/ns/javaee"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

  <filter>

        <filter-name>struts2</filter-name>

        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

    </filter>

    <filter-mapping>

        <filter-name>struts2</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

</web-app>

Struct.xml(每次换类名

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC

    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"

    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <constant name="struts.devMode" value="true" />

    <package name="login" extends="struts-default" namespace="/login">

        <action name="login*" class="com.bjsxt.struts2.user.action.LoginAction{1}">

            <result>/user_login_success.jsp</result>

        </action>

    </package>

</struts>

拿的时候

index.jsp

<?xml version="1.0" encoding="GB18030" ?>

<%@ page language="java" contentType="text/html; charset=GB18030"

    pageEncoding="GB18030"%>

<% String context = request.getContextPath(); %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=GB18030" />

<title>Insert title here</title>

</head>

<body>

取得Map类型request,session,application,真实类型 HttpServletRequest, HttpSession, ServletContext的引用:

<ol>

    <li>前三者：依赖于容器</li>

    <li>前三者：IOC</li> (只用这种)

    <li>后三者：依赖于容器</li>

    <li>后三者：IOC</li>

</ol>

<br />

<form name="f" action="" method="post">

用户名：<input type="text" name="name"/>

密码：<input type="text" name="password"/>

<br />

<input type="button" value="submit1" onclick="javascript:document.f.action='login/login1';document.f.submit();" />

<input type="button" value="submit2" onclick="javascript:document.f.action='login/login2';document.f.submit();" />

<input type="button" value="submit3" onclick="javascript:document.f.action='login/login3';document.f.submit();" />

<input type="button" value="submit4" onclick="javascript:document.f.action='login/login4';document.f.submit();" />

</form>

</body>

</html>

user_login_success.jsp

<?xml version="1.0" encoding="GB18030" ?>

<%@ page language="java" contentType="text/html; charset=GB18030"

    pageEncoding="GB18030"%>

    <%@taglib uri="/struts-tags" prefix="s" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=GB18030" />

<title>Insert title here</title>

</head>

<body>

    User Login Success!

    <br />

    <s:property value="#request.r1"/> | <%=request.getAttribute("r1") %> <br />

    <s:property value="#session.s1"/> | <%=session.getAttribute("s1") %> <br />

    <s:property value="#application.a1"/> | <%=application.getAttribute("a1") %> <br />

    <s:property value="#attr.a1"/><br />     //不常用 无法精确的知道到底存在哪里 他是吧request application session 的全部存在里面

    <s:property value="#attr.s1"/><br />

    <s:property value="#attr.r1"/><br />

    <s:debug></s:debug>

    <br />

</body>

</html>

先介绍第一种‘

LoginAction1

package com.bjsxt.struts2.user.action;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction1 extends ActionSupport {

    private Map request;

    private Map session;

    private Map application;

    public LoginAction1() {

        request = (Map)ActionContext.getContext().get("request");

        session = ActionContext.getContext().getSession();

        application = ActionContext.getContext().getApplication();

    }

    public String execute() {

        request.put("r1", "r1");

        session.put("s1", "s1");

        application.put("a1", "a1");

        return SUCCESS;

    }

}

第二种： IOC控制反转依赖于容器

LoginAction2

package com.bjsxt.struts2.user.action;

import java.util.Map;

import org.apache.struts2.interceptor.ApplicationAware;

import org.apache.struts2.interceptor.RequestAware;

import org.apache.struts2.interceptor.SessionAware;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware {

    private Map<String, Object> request;

    private Map<String, Object> session;

    private Map<String, Object> application;

    //DI dependency injection

    //IoC inverse of control

    public String execute() {

        request.put("r1", "r1");

        session.put("s1", "s1");

        application.put("a1", "a1");

        return SUCCESS;

    }

    @Override

    public void setRequest(Map<String, Object> request) {

        this.request = request;

    }

    @Override

    public void setSession(Map<String, Object> session) {

        this.session = session;

    }

    @Override

    public void setApplication(Map<String, Object> application) {

        this.application = application;

    }

}

第三种

LoginAction3

package com.bjsxt.struts2.user.action;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction3 extends ActionSupport {

    private HttpServletRequest request;

    private HttpSession session;

    private ServletContext application;

    public LoginAction3() {

        request = ServletActionContext.getRequest();

        session = request.getSession();

        application = session.getServletContext();

    }

    public String execute() {

        request.setAttribute("r1", "r1");

        session.setAttribute("s1", "s1");

        application.setAttribute("a1", "a1");

        return SUCCESS;

    }

}

第四种 IOC

package com.bjsxt.struts2.user.action;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ServletRequestAware;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction4 extends ActionSupport implements ServletRequestAware {

    private HttpServletRequest request;

    private HttpSession session;

    private ServletContext application;

    public String execute() {

        request.setAttribute("r1", "r1");

        session.setAttribute("s1", "s1");

        application.setAttribute("a1", "a1");

        return SUCCESS;

    }

    @Override

    public void setServletRequest(HttpServletRequest request) {

        this.request = request;

        this.session = request.getSession();

        this.application = session.getServletContext();

    }

}

LoginAction4

码农公寓

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