1.创建动态web工程
2.编写model类,提供一个无参的构造方法和一个唯一的标识属性,为每个属性提供一个setter和getter的方法。
package org.itat.zttc.model;
public class Person {
private int id;
private String name;
private double salary;
private int age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Person(int id,String name,double salary,int age) {
super();
this.id = id;
this.name = name;
this.salary = salary;
this.age = age;
}
public Person() {
}
}
3.编写PersonServlet类,让这个类继承HttpServlet,并重写doget和dopost方法
package org.itat.zttc.ajax;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.itat.zttc.model.Person;
import org.itat.zttc.util.XStreamUtil;
public class PersonServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
Map<Integer,List<Person>> persons = new HashMap<Integer,List<Person>>();
public PersonServlet() {
super();
List<Person> ps = new ArrayList<Person>();
ps.add(new Person(1,"张三",1200,22));
ps.add(new Person(2,"李四",1300,23));
ps.add(new Person(3,"王五",1400,24));
persons.put(1,ps);
ps = new ArrayList<Person>();
ps.add(new Person(11,"刘德华",12000,32));
ps.add(new Person(12,"周杰伦",13000,33));
ps.add(new Person(13,"张曼玉",14000,34));
ps.add(new Person(14,"梁朝伟",15000,35));
persons.put(2,ps);
ps = new ArrayList<Person>();
ps.add(new Person(21,"孙悟空",22000,132));
ps.add(new Person(22,"猪八戒",23000,133));
ps.add(new Person(23,"沙和尚",24000,134));
ps.add(new Person(24,"唐和尚",25000,135));
persons.put(3,ps);
}
protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request,IOException {
//1、由于返回的是xml,需要为respose设置contentType
response.setContentType("text/xml;charset=utf-8");
//2、获取Writer
Writer out = response.getWriter();
//3、获取部门id
int did = Integer.parseInt(request.getParameter("did"));
//4、获取用户列表对象,
List<Person> ps = persons.get(did);
//5、拼接xml
StringBuffer px = new StringBuffer();
px.append("<persons>");
for(Person p:ps) {
px.append("<person>");
px.append("<id>").append(p.getId()).append("</id>");
px.append("<name>").append(p.getName()).append("</name>");
px.append("<salary>").append(p.getSalary()).append("</salary>");
px.append("<age>").append(p.getAge()).append("</age>");
px.append("</person>");
}
px.append("</persons>");
//6、通过out写回去
out.write(px.toString());
}
}
4.配置web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 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_3_0.xsd">
<display-name>ajax01</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<description></description>
<display-name>PersonServlet</display-name>
<servlet-name>PersonServlet</servlet-name>
<servlet-class>org.itat.zttc.ajax.PersonServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>PersonServlet</servlet-name>
<url-pattern>/person.do</url-pattern>
</servlet-mapping>
</web-app> 访问http://localhost:8080/ajax02/person.do?did=1会出现
<persons><person><id>1</id><name>张三</name><salary>1200.0</salary><age>22</age></person><person><id>2</id><name>李四</name><salary>1300.0</salary><age>23</age></person><person><id>3</id><name>王五</name><salary>1400.0</salary><age>24</age></person></persons>5.编写personXml.html文件
<!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> <script type="text/javascript"> window.onload = init; function init() { //1、获取部门节点 var dn = document.getElementById("dep"); //2、为该节点创建onchange dn.onchange = getPerson //3、创建一个getPerson的方法来处理事件 } function getPerson() { var did = this.value; //1、获取XMLHttpRequest; var xhr = createXMLHttpRequest(); //2、通过xhr来打开页面,使用POST xhr.open("POST","person.do",true); xhr.onreadystatechange = function() { //3、处理请求 if(xhr.readyState==4&&xhr.status==200) { //3.1、获取xml节点 var xmlDoc = xhr.responseXML; //由于response的contentType是text/xml类型,此时就只能获取节点 //alert(xhr.resonseText); //3.2、获取所有的person节点 var pns = xmlDoc.getElementsByTagName("person"); //3.3、遍历所以节点,获取id,name等信息 var node = ""; for(var i=0;i<pns.length;i++) { node+=getValueByProp(pns[i],"id")+"----------"+ getValueByProp(pns[i],"name")+"----------"+ getValueByProp(pns[i],"salary")+"----------"+ getValueByProp(pns[i],"age")+"<br/>" } //3.4、写入到persons document.getElementById("persons").innerHTML = node; } } xhr.setRequestHeader("Content-type","application/x-www-form-urlencoded"); xhr.send("did="+did); //4、发送信息,需要传入did } //根据节点获取值 function getValueByProp(node,prop) { return (node.getElementsByTagName(prop))[0].firstChild.nodeValue; } function createXMLHttpRequest() { if(window.XMLHttpRequest) { //针对其他主流浏览器 return new XMLHttpRequest(); } else if(window.ActiveXObject) { //针对IE5和IE6 return new ActiveXObject("Microsoft.XMLHTTP"); } else { alert("你使用的浏览器不支持XMLHttpRequest,请换一个浏览器再试!"); return null; } } </script> </head> <body> <select id="dep"> <option value="1">普通组</option> <option value="2">明星组</option> <option value="3">火星组</option> </select> <div id="persons"></div> </body> </html>
尝试访问一下http://localhost:8080/ajax02/personXml.html。

