SpringMVC07处理器方法的返回值
<body> <!--返回值是string的内部视图 --> <a href="student/add">add</a> <!--返回值是string的外部视图 --> <a href="student/taobao">淘宝</a> <!--没有返回值 转发到内部视图 --> <a href="student/request">request</a> <!--没有返回值 重定向到内部视图 --> <a href="student/response">response</a> </body>
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <!-- 配置springmvc的组件 --> <context:component-scan base-package="cn.bdqn.controller"/> <!-- 视图解析器 后台返回的是 success! 应该拿到的是 /WEB-INF/jsp/success.jsp <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> --> <!-- 配置外部视图解析器 就不需要 视图解析器了！ --> <bean class="org.springframework.web.servlet.view.BeanNameViewResolver"/> <!-- 外部视图 --> <bean id="taobao" class="org.springframework.web.servlet.view.RedirectView"> <property name="url" value="http://www.taobao.com"/> </bean> </beans>
@Controller @RequestMapping("/student") public class StudentController { /** * 返回值是string的内部视图 */ @RequestMapping("/add") public String add(){ System.out.println("进入了add"); return "success"; } /** * 返回值是string的外部视图 */ @RequestMapping("/taobao") public String taobao(){ System.out.println("进入了taobao"); return "taobao"; } /** * 没有返回值 转发到内部视图 */ @RequestMapping("/request") public void request(HttpServletRequest request,HttpServletResponse response){ System.out.println("进入了request"); //转发 try { request.getRequestDispatcher("/WEB-INF/jsp/success.jsp").forward(request, response); } catch (ServletException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } /** * 没有返回值 重定向到内部视图 */ @RequestMapping("/response") public void response(HttpServletRequest request,HttpServletResponse response){ System.out.println("进入了response"); //重定向 try { /** * 重定向是 客户端的 行为！ * 能直接访问 web-inf ??? 不行！ * response.sendRedirect("WEB-INF/jsp/success.jsp"); * 重定向到另一个方法 然后 那个方法做跳转！ * */ response.sendRedirect("success.jsp"); //前提是根目录下有 success.jsp /** * 这时候的路径http://localhost:8080/springmvc08/student/success.jsp * 为什么会有student/这一层目录 * 原因： * 用户点击的是 student/response * 系统会默认拿到student/ 当成目前的路径！ * 再做重定向的时候会默认加上student/ */ } catch (IOException e) { e.printStackTrace(); } } }
<body> <!-- 在controller中 实现 方法之间的跳转 --> <form action="student/changeMethod" method="post"> 学生姓名：<input type="text" name="name"/> 年龄： <input type="password" name="age"/> <input type="submit" value="新增"/> </form> </body>
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <!-- 配置springmvc的组件 --> <context:component-scan base-package="cn.bdqn.controller"/> <!-- 视图解析器 后台返回的是 success! 应该拿到的是 /WEB-INF/jsp/success.jsp --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
@Controller @RequestMapping("/student") public class StudentController { /** * 转发是默认的格式 * 01.看路径 * 02.看数据是否传递 */ @RequestMapping("/addRequest") public ModelAndView addRequest(Student student){ System.out.println("进入了addRequest"); ModelAndView mv=new ModelAndView(); mv.addObject("student", student).setViewName("success"); return mv; } /** * 重定向 * 01.客户端行为 不能访问WEB-INF * 02.以访问的路径为准，所以上个例子中的student/ 会出现！ * 03.如果使用重定向 不加/ 就是以上次访问的路径为准 * 如果加上了/ 就是以项目的跟路径为准 */ @RequestMapping("/addResponse") public ModelAndView addResponse(Student student){ System.out.println("进入了addResponse"); ModelAndView mv=new ModelAndView(); //需要在 webroot下 创建 success.jsp mv.addObject("student", student).setViewName("redirect:/success.jsp"); return mv; } /** * 跳转到内部方法 */ @RequestMapping("/changeMethod") public String changeMethod(Student student){ System.out.println("进入了changeMethod"); ModelAndView mv=new ModelAndView(); mv.addObject("student", student); //return "redirect:list"; 重定向 不能使用 / 跳转到当前controller中的list方法 ! 数据丢失 return "forward:list";// 转发list方法 数据肯定保留 } @RequestMapping("/list") public String list(Student student){ System.out.println("进入了list"); System.out.println(student.getName()); System.out.println(student.getAge()); return "success"; } }
==================接收并返回json数据======================
需要导入jquery和 Gson的jar包
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ $("button").click(function(){ //按钮的点击事件 $.ajax({ url:"user/doAjax", data:{ name:"小黑", age:50 }, success:function(data){ /* 01.在前台转换成json数据 var json=eval("("+data+")"); alert(json.name+ " "+json.age); */ /* 02.在后台设置response.setContentType("application/json"); */ alert(data.name+ " "+data.age); } }) }) }) </script> </head> <body> <button>提交ajax请求</button> </body> </html>
<?xml version="1.0" encoding="UTF-8"?> <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-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!-- 配置需要扫描的包 --> <context:component-scan base-package="cn.bdqn.controller"/> <!-- 允许静态资源的访问 --> <mvc:resources location="/js/" mapping="/js/**"/> <!-- 开启注解 --> <mvc:annotation-driven/> <!-- 之前的 <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"></bean> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"></bean> --> </beans>
@Controller @RequestMapping("/user") public class MyController { @RequestMapping("doAjax") public void doAjax(String name, int age, HttpServletResponse response) throws IOException { System.out.println("进入了doAjax......"); System.out.println(name); System.out.println(age); // 放入map集合 Map<String, Object> map = new HashMap<String, Object>(); map.put("name", name); map.put("age", age); // response.setHeader("Content-type", "text/html;charset=utf-8"); response.setContentType("application/json"); // 设置返回的是json页面 Gson gson = new Gson(); String json = gson.toJson(map); System.out.println("json=====" + json); // 把json数据返回给界面 PrintWriter writer = response.getWriter(); writer.print(json); } }
=================ajax验证用户名是否存在====================
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'success.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ //验证用户名是否存在 $("#userName").blur(function(){ //按钮的点击事件 var name= $("#userName").val(); $.ajax({ url:"user/addUser", type:"post", data:"userName="+name, success:function(data){ alert(data); } }) }) }) </script> </head> <body> <h1>json验证</h1> 用户名：<input type="text" id="userName" name="userName"> </body> </html>
/** * 用户名验证 ajax */ @RequestMapping("/addUser") public void doAjax(String name, HttpServletResponse response) throws IOException { System.out.println("进入了addUser......"); System.out.println(name); boolean flag = false; if (name.equals("admin")) { flag = true; } response.setContentType("application/json"); // 设置返回的是json页面 Gson gson = new Gson(); String json = gson.toJson(flag); System.out.println("json=====" + json); // 把json数据返回给界面 PrintWriter writer = response.getWriter(); writer.write(json); }
==================处理器返回Object对象=====================
导入需要的Jackson jar包
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ $("button").click(function(){ //按钮的点击事件 $.ajax({ url:"user/doAjax", success:function(data){ // alert(data) 返回单个数据 使用 // alert(data.name+" "+data.age);返回一个对象使用 //alert(data.user1.name+" "+data.user2.name); 返回一个map集合 $(data).each(function(i){ alert(data[i].name+" "+data[i].age); //返回一个list集合 }) } }) }) }) </script> </head> <body> <button>提交ajax请求</button> </body> </html>
package cn.bdqn.controller; import java.util.ArrayList; import java.util.List; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import cn.bdqn.bean.User; @Controller @RequestMapping("/user") public class MyController { /** * 01.返回的是一个Object对象 * @return */ /** @RequestMapping("/doAjax") @ResponseBody // 把我们的返回的数据 放在相应体中 public Object doAjax() { System.out.println("进入了doAjax......"); return 45454.2515; }*/ /** * 02.返回的是一个Object对象 * produces :响应的界面格式 */ /**@RequestMapping(value = "/doAjax", produces = "text/html;charset=utf-8") @ResponseBody // 把我们的返回的数据 放在相应体中 public Object doAjax() { System.out.println("进入了doAjax......"); return "大家辛苦了"; }*/ /** * 03.返回的是一个Object对象 */ /**@RequestMapping(value = "/doAjax") @ResponseBody // 把我们的返回的数据 放在相应体中 public Object doAjax() { System.out.println("进入了doAjax......"); return new User("小黑", 50); }*/ /** * 04.返回的是一个Map集合 */ /**@RequestMapping(value = "/doAjax") @ResponseBody // 把我们的返回的数据 放在相应体中 public Object doAjax() { System.out.println("进入了doAjax......"); Map<String, Object> map = new HashMap<String, Object>(); map.put("user1", new User("小黑1", 50)); map.put("user2", new User("小黑2", 50)); return map; }*/ /** * 05.返回的是一个list集合 */ @RequestMapping(value = "/doAjax") @ResponseBody // 把我们的返回的数据 放在相应体中 public Object doAjax() { System.out.println("进入了doAjax......"); List<User> list = new ArrayList<User>(); list.add(new User("小黑1", 50)); list.add(new User("小黑2", 60)); return list; } }
