Three ways to get SERVLETAPI in the action class in 5.struts2

Access to **servlet APIs (occasionally used in development) **1. In the action class, you can also get to the servlet some common APIs, there are three ways to get the * fully decoupled way * Using interface injection method * Use static methods in Servletactioncontext to access the api* requirements of the servlet directly: Provide data for the JSP's form page, receive it in the action using the Servlet's API, then save it to three domain objects, and then display it on the JSP page. * Provide JSP registration page, demonstrate the following three ways:
 Demo4.jsp: 
 
<%@ 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" >
Struts_demo4.xml:
<?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><package name=" Demo4 "extends=" Struts-default "namespace="/"><!-- The fully decoupled way--><action name= "regist" class= "Demo4. Useraction "method=" regist "><result>/demo4/success.jsp</result></action><!--Interface Injection Method-- ><action name= "Regist2" class= "Demo4. UserAction2 "method=" Regist "><result>/demo4/success.jsp</result></action> <!-- Use the Servletactioncontext object--><action name= "Regist3" class= "Demo4". UserAction3 "method=" Regist "><result>/demo4/success.jsp</result></action></package> </struts>
Action:
Package Demo4;import Java.util.map;import Com.opensymphony.xwork2.actioncontext;import com.opensymphony.xwork2.actionsupport;/** * Fully decoupled way * @author MJL * */public class Useraction extends Actionsupport{publ IC String regist () {//Receive form data//Get to Actioncontext object Actioncontext context=actioncontext.getcontext ();//Get the requested parameter map <string, object> map = Context.getparameters ();//Get value by key string[] Username= (string[]) map.get ("username"); String[] password= (string[]) map.get ("password"); System.out.println ("User name:" +username[0]+ ", Password:" +password[0]);//Get sessionmap<string, object> sessionmap = Context.getsession ();//Like the map deposit specific values Sessionmap.put ("Sessname", "Meimei"); return SUCCESS;}} Package Demo4;import Javax.servlet.http.httpservletrequest;import Org.apache.struts2.interceptor.servletrequestaware;import Com.opensymphony.xwork2.actionsupport;public Class UserAction2 extends Actionsupport implements servletrequestaware{private httpservletrequest request;public void Setservletrequest (HttpServletRequest RequeST) {this.request=request;} Public String Regist () {string Username=request.getparameter ("username"); request.getsession (). SetAttribute (" Sessname ", username); return SUCCESS;}} Package Demo4;import Javax.servlet.http.httpservletrequest;import Org.apache.struts2.servletactioncontext;import com.opensymphony.xwork2.actionsupport;/** * Method of using Servletactioncontext Object * @author MJL * */public class UserAction3 Extends Actionsupport{public String regist () {HttpServletRequest request = Servletactioncontext.getrequest (); String Username=request.getparameter ("username"); request.getsession (). SetAttribute ("Sessname", username); return SUCCESS;}}
　　
　　
Three ways to get SERVLETAPI in the action class in 5.struts2