json对象和数组

jsp页面

<script type="text/javascript">
    function getUserByUserId(){
        $.post("getUserServlet",{userId:1},function(data){
            alert(data.userId);
            alert(data.username);
            alert(data.sex);
            alert(data.password);
            alert(data.flag);
        },"json");//返回对象和对数组
    }

    function getUserListPage(){
        $.post("getUserListPage",{pageNO:1},function(data){
            $.each(data, function(i, user){
              $("#userTab").append("<tr style='text-align: center;'><td>"+ user.userId + "</td><td>"+ user.username + "</td><td>"+ user.sex + "</td><td>"+ user.password + "</td><td>"+ user.flag + "</td>" +"</tr>");
            });
        },"json");
    }
</script>

<hr>
<table id="userTab" border="1px">
    <tr style="text-align: center;">
        <td>用户ID</td>
        <td>用户名</td>
        <td>性别</td>
        <td>密码</td>
        <td>状态</td>
    </tr>

</table>

servlet对象
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.alibaba.fastjson.JSON;
import com.beiruan.entity.User;
import com.beiruan.service.UserService;
import com.beiruan.service.impl.UserServiceImpl;

public class GetUserServlet 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 {

    String userIdStr = request.getParameter("userId");
    int userId = Integer.parseInt(userIdStr);

    UserService userService = new UserServiceImpl();
    User user = userService.getUserByUserId(userId);

    PrintWriter out = response.getWriter();
    String json = JSON.toJSONString(user);
    System.out.println(json);
    out.print(json);
}

}

数组servlet

public class GetUserListPage 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 {

String pageNOStr = request.getParameter(“pageNO”);
int pageNO = Integer.parseInt(pageNOStr);

UserService userService = new UserServiceImpl();
List userList = userService.getUserListPage(pageNO, 10);
String json = JSON.toJSONString(userList);
System.out.println(json);
response.setContentType(“text/html;charset=UTF-8”);
PrintWriter out = response.getWriter();
out.print(json);
out.flush();
out.close();
}

}

查询出数据库所有user的数据显示在页面
查询的结果