四、数据的返回以及页面的跳转
页面：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Titletitle>
<script src="js/jquery.min.js">script>
<script>
// 页面加载，绑定单击事件
$(function(){
$("#btn").click(function(){
// 发送ajax请求
$.ajax({
// 编写json格式，设置属性和值
url:"user/testAjax",
contentType:"application/json;charset=UTF-8",
data:'{"username":"jack","password":"123","age":30}',
dataType:"json",
type:"post",
success:function(data){
// data服务器端响应的json的数据，进行解析
alert(data.username+','+data.password+','+data.age);
}
});
});
});
script>
head>
<body>
<a href="user/testString" >returnType: Stringa>
<br/>
<a href="user/testVoid" >returnType: Voida>
<br/>
<a href="user/testModelAndView" >testModelAndViewa>
<br/>
<a href="user/testForwardOrRedirect" >testForwardOrRedirecta>
<br/>
<button id="btn">发送ajax的请求button>
body>
html>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
<title>Titletitle>
head>
<body>
<h3>执行成功h3>
${user.username}
${user.password}
body>
html>
1、返回String
@Controller
@RequestMapping("/user")
public class UserController {
@RequestMapping("/testString")
public String testString(Model model){
System.out.println("testString方法执行了...");
// 模拟从数据库中查询出User对象
User user = new User();
user.setUsername("jack");
user.setPassword("123456");
user.setAge(30);
// model对象
model.addAttribute("user",user);
return "success";
}
}
2、无返回值的情况
①请求转发
@RequestMapping("/testVoid")
public void testVoid(HttpServletRequest request, HttpServletResponse response) throws Exception {
System.out.println("testVoid方法执行了...");
// 编写请求转发的程序
request.getRequestDispatcher("/WEB-INF/pages/success.jsp").forward(request,response);
return;
}
②重定向
@RequestMapping("/testVoid")
public void testVoid(HttpServletRequest request, HttpServletResponse response) throws Exception {
System.out.println("testVoid方法执行了...");
// 重定向
response.sendRedirect(request.getContextPath()+"/index.jsp");
return;
}
也可以使用关键字进行转发和重定向
@RequestMapping("/testForwardOrRedirect")
public String testForwardOrRedirect(){
System.out.println("testForwardOrRedirect方法执行了...");
// 请求的转发
return "forward:/WEB-INF/pages/success.jsp";
// 重定向
return "redirect:/index.jsp";
}
③直接响应数据
@RequestMapping("/testVoid")
public void testVoid(HttpServletRequest request, HttpServletResponse response) throws Exception {
System.out.println("testVoid方法执行了...");
// 设置中文乱码
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
// 直接会进行响应
response.getWriter().print("你好");
return;
}
3、返回ModelAndView对象
@RequestMapping("/testModelAndView")
public ModelAndView testModelAndView(){
// 创建ModelAndView对象
ModelAndView mv = new ModelAndView();
System.out.println("testModelAndView方法执行了...");
// 模拟从数据库中查询出User对象
User user = new User();
user.setUsername("jack");
user.setPassword("123456");
user.setAge(30);
// 把user对象存储到mv对象中，也会把user对象存入到request对象
mv.addObject("user",user);
// 跳转到哪个页面
mv.setViewName("success");
return mv;
}
4、接收返回异步请求数据
静态资源的过滤，前端控制器DispatcherServlet将会进行拦截，需要在springmvc.xml中进行配置
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.liaoxiang"/>
<bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
bean>
<mvc:resources location="/css/" mapping="/css/**"/>
<mvc:resources location="/images/" mapping="/images/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<mvc:annotation-driven />
beans>
<script>
// 页面加载，绑定单击事件
$(function(){
$("#btn").click(function(){
// 发送ajax请求
$.ajax({
// 编写json格式，设置属性和值
url:"user/testAjax",
contentType:"application/json;charset=UTF-8",
data:'{"username":"jack","password":"123","age":30}',
dataType:"json",
type:"post",
success:function(data){
// data服务器端响应的json的数据，进行解析
alert(data.username+','+data.password+','+data.age);
}
});
});
});
</script>
@ResponseBody
@RequestMapping("/testAjax")
public User testAjax(@RequestBody User user){
System.out.println("testAjax方法执行了...");
// 客户端发送ajax的请求，传的是json字符串，后端把json字符串封装到user对象中
System.out.println(user);
// 做响应，模拟查询数据库
user.setUsername("rose");
user.setAge(40);
// 做响应
return user;
}
