An example of Ajax asynchronous invocation using XMLHttpRequest combined with struts2 __ajax

On the Internet to find information, it is really tangled, patchwork, although this writing is very simple, but it cost me a lot of Kung Fu, in order to help the students behind, resolute paste code, hope for everyone useful.

Function Description: Implement the asynchronous invocation using XMLHttpRequest to achieve the effect of the Select Cascade Drop-down menu.

The screenshot of the project is as follows (mainly for everyone to see the introduction of the jar package):

The code for the Action class:

Package com.action;
Import java.util.ArrayList;
Import Java.util.Arrays;
Import Java.util.HashMap;
Import java.util.List;
Import Java.util.Map;

Import Java.util.Set;

Import Org.apache.struts2.ServletActionContext;

Import Com.opensymphony.xwork2.ActionSupport;
	
	public class AjaxTest1 extends Actionsupport {private map<string,list<string>> datas;
	
	Private list<string> provinces;
	
	Private List<string> citys;
		
		Public AjaxTest1 () {datas = new hashmap<string,list<string>> ();
		String[] C1 = new string[]{"Wuhan", "Xiangfan", "Jingzhou", "Yichang"};
		
		string[] C2 = new string[]{"Haidian", "Changping", "Chaoyang"};
		Datas.put ("Hubei", Arrays.aslist (C1));
	Datas.put ("Beijing", Arrays.aslist (C2));
	Public list<string> getprovinces () {return provinces;
	public void Setprovinces (list<string> provinces) {this.provinces = provinces;
	Public list<string> Getcitys () {return citys; } public void Setcitys (List<string> citys) {This.citys= Citys;
		Public String loadprovinces () {list<string> List = new arraylist<string> ();
		set<string> set = Datas.keyset ();
		for (String s:set) {List.add (s);
		
		} System.out.println (list);
		
		
		This.setprovinces (list);
		
		System.out.println ("Provinces:" +provinces);
	return SUCCESS;
		public string Loadcitys () {String province = Servletactioncontext.getrequest (). GetParameter ("province");
		
		This.setcitys (Datas.get ("Hubei"));
		
		System.out.println ("Returned province value is:" +province);
		list<string> list = new arraylist<string> ();
		This.setcitys (Datas.get (province));
	return SUCCESS; }
	
}

Struts.xml File:

<?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.enable.DynamicMethodInvocation "value=" false "/&
    Gt <constant name= "Struts.devmode" value= "true"/> <!--<package name= "Default" namespace= "/" extends= "strut S-default "> <default-action-ref name=" index "/> <global-results> <result N
            Ame= "Error" >/error.jsp</result> </global-results> <global-exception-mappings> 

        <exception-mapping exception= "java.lang.Exception" result= "error"/> </global-exception-mappings> <action name= "index" > <result type= "redirectaction" > <param name= "act Ionname ">HelloWorld</param> <param name=" namespace ">/example</param> </result> </action> </package> <include file= "Example.xml "/> ADD packages here--> <package name=" test1 "namespace="/"extends=" Json-default "> ; Action name= "loadprovinces" class= "Com.action.AjaxTest1" method= "loadprovinces" > <result name= "Success" type = "JSON" > <!--<param name= "includeproperties" >provinces</param>--> <param N Ame= "Excludeproperties" >citys</param> </result> </action> <action name= " Loadcitys "class=" Com.action.AjaxTest1 "method=" Loadcitys "> <result type=" JSON "> <param name=" E Xcludeproperties ">provinces</param> </result> </action> </package> </str Uts>

index.jsp Paging File:

<%@ page language= "java" import= "java.util.*" pageencoding= "Utf-8"%> <% @taglib prefix= "s" uri= "/struts-tags"
%> <% String Path = Request.getcontextpath ();
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/"; %> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >  


Well, it's done, grind and grind carefully.