<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="js/jquery-3.6.0.js"></script>
</head>
<script>
function action(){
$.ajax({
url:"/ajax/logins",
type:"get",
dataType:"json",
data:{"name":"李四", "age": 22},
success:function (result){
//后台响应的是一个Json格式的java字符串，jquery会自动将这个字符串转化为json格式的js对象，简称json对向
console.log(result.code)
console.log(result.meg)
console.log(result.data.length)
// console.log("")
for (let i = 0; i < result.data.length; i++) {
console.log(result.data[i].name)
console.log(result.data[i].age)
}
},
error:function (){
alert("error")
}
});
}
</script>
<body>
<p>
<input type="button" value="ajax" onclick="action()">
</p>
<p>
<input type="text" id="uu">
</p>
</body>
</html>
package com.zzc.servlet;
import com.fasterxml.jackson.databind.ObjectMapper;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
public class AjaxServlet1 extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding( "utf-8" );
// 不能向ajax响应一个页面，所以text/html不可用application/json
resp.setContentType( "application/json;charset=utf-8" );
System.out.println(req.getParameter( "name" ));
System.out.println(req.getParameter( "age" ));
// System.out.println(req.getParameter( "sex" ));
//jackson提供的api
ObjectMapper mapper = new ObjectMapper();
User user = new User("张三",88);
User user2 = new User("王五",22);
User user3= new User("王二麻子",38);
User user4 = new User("朱青山岛",438);
//将java对象转换成json格式的字符串
ArrayList<User> users = new ArrayList<>();
users.add( user );
users.add( user2 );
users.add( user3 );
users.add( user4 );
R r = new R();
r.setCode( 200 );
r.setMeg( "转换ok" );
r.setData(users);
String value = mapper.writeValueAsString( r );
System.out.println( value );
//不能向ajax响应一个页面
PrintWriter out = resp.getWriter();
out.write( value );
out.close();
}
}
package com.zzc.servlet;
public class User {
private String name;
private int age;
public User(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
package com.zzc.servlet;
import java.util.List;
public class R {
private int code;
private String meg;
private List<User> data;
@Override
public String toString() {
return "R{" +
"code=" + code +
", meg='" + meg + '\'' +
", data=" + data +
'}';
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getMeg() {
return meg;
}
public void setMeg(String meg) {
this.meg = meg;
}
public List<User> getData() {
return data;
}
public void setData(List<User> data) {
this.data = data;
}
}