1.后台返回text类型的数据

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%    String path = request.getContextPath();    String basePath = request.getScheme() + "://"            + request.getServerName() + ":" + request.getServerPort()            + path + "/";%>
      
      
      
      
          
                       用户名：   

 

public class AjaxServlet extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        doPost(request, response);    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        System.out.println("进入了ajax..........");        response.setHeader("Content-type", "text/html;charset=utf-8");         // 01.获取ajax请求过来的name值        String name = request.getParameter("name");            response.getWriter().print(name);            }}

 

2.返回单个对象

public class Student {    private String name;    private String pwd;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getPwd() {        return pwd;    }    public void setPwd(String pwd) {        this.pwd = pwd;    }    public Student(String name, String pwd) {        super();        this.name = name;        this.pwd = pwd;    }    public Student() {        super();    }    @Override    public String toString() {        return "Student [name=" + name + ", pwd=" + pwd + "]";    }}

 

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%    String path = request.getContextPath();    String basePath = request.getScheme() + "://"            + request.getServerName() + ":" + request.getServerPort()            + path + "/";%>
      
      
      
      
          
                       用户名：      
      
   

 

public class AjaxServlet extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        doPost(request, response);    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        System.out.println("进入了ajax..........");        response.setHeader("Content-type", "text/html;charset=utf-8");        // 创建一个Student对象 返回给前台        Student student = new Student("admin1", "123456");        // 需要把student对象转换成json格式        System.out.println("转换前==》" + student);        Gson gson = new Gson();        // json 就是转换之后的 student对象 {"name":"admin","pwd":"123456"}        String json = gson.toJson(student);        System.out.println("转换后==" + json);        response.getWriter().print(json);    }}

 

3.返回对象的集合

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%    String path = request.getContextPath();    String basePath = request.getScheme() + "://"            + request.getServerName() + ":" + request.getServerPort()            + path + "/";%>
      
      
      
      
          
                       用户名：      
      
   

 

public class AjaxServlet extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        doPost(request, response);    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        System.out.println("进入了ajax..........");        response.setHeader("Content-type", "text/html;charset=utf-8");        Student student1 = new Student("admin1", "123456");        Student student2 = new Student("admin2", "123456");        Student student3 = new Student("admin3", "123456");        Student student4 = new Student("admin4", "123456");        ArrayList
      
        list = new ArrayList
       
        ();        list.add(student1);        list.add(student2);        list.add(student3);        list.add(student4);        System.out.println("转换前==》" + list);        Gson gson = new Gson();        String json = gson.toJson(list);        System.out.println(json);        response.getWriter().print(json);    }}