SpringMVC简单使用教程

一、SpringMVC简单入门，创建一个HelloWorld程序

　　1.首先，导入SpringMVC需要的jar包。

　　

　　2.添加Web.xml配置文件中关于SpringMVC的配置

  <!--configure the setting of springmvcDispatcherServlet and configure the mapping-->
   <servlet>
       <servlet-name>springmvc</servlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
       <init-param>
             <param-name>contextConfigLocation</param-name>
             <param-value>classpath:springmvc-servlet.xml</param-value>
         </init-param>
         <!-- <load-on-startup>1</load-on-startup> -->
   </servlet>
 <servlet-mapping>
       <servlet-name>springmvc</servlet-name>
       <url-pattern>/</url-pattern>
   </servlet-mapping>

　　3.在src下添加springmvc-servlet.xml配置文件

 <?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:mvc="http://www.springframework.org/schema/mvc"
     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-4.1.xsd
         http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
 <!-- scan the package and the sub package -->
     <context:component-scan base-package="test.SpringMVC"/>
 <!-- don't handle the static resource -->
     <mvc:default-servlet-handler />
 <!-- if you use annotation you must configure following setting -->
     <mvc:annotation-driven />

     <!-- configure the InternalResourceViewResolver -->
     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
             id="internalResourceViewResolver">
         <!-- 前缀 -->
         <property name="prefix" value="/WEB-INF/jsp/" />
         <!-- 后缀 -->
         <property name="suffix" value=".jsp" />
     </bean>
 </beans>

　　4.在WEB-INF文件夹下创建名为jsp的文件夹，用来存放jsp视图。创建一个hello.jsp，在body中添加“Hello World”。

　　5.建立包及Controller，如下所示:

　　

　　6.编写Controller代码

 @Controller
 @RequestMapping("/mvc")
 public class mvcController {
 @RequestMapping("/hello")
     public String hello(){
         return "hello";
     }
 }

　　7.启动服务器，键入 http://localhost:8080/项目名/mvc/hello

二、配置解析

1.Dispatcherservlet
　　DispatcherServlet是前置控制器，配置在web.xml文件中的。拦截匹配的请求，Servlet拦截匹配规则要自已定义，把拦截下来的请求，依据相应的规则分发到目标Controller来处理，是配置spring MVC的第一步。

2.InternalResourceViewResolver
视图名称解析器

3.以上出现的注解
@Controller 负责注册一个bean 到spring 上下文中
@RequestMapping 注解为控制器指定可以处理哪些 URL 请求

三、SpringMVC常用注解

@Controller
负责注册一个bean 到spring 上下文中

@RequestMapping
注解为控制器指定可以处理哪些 URL 请求

@RequestBody
该注解用于读取Request请求的body部分数据，使用系统默认配置的HttpMessageConverter进行解析，然后把相应的数据绑定到要返回的对象上 ,再把HttpMessageConverter返回的对象数据绑定到 controller中方法的参数上

@ResponseBody
 该注解用于将Controller的方法返回的对象，通过适当的HttpMessageConverter转换为指定格式后，写入到Response对象的body数据区

@ModelAttribute 
在方法定义上使用 @ModelAttribute 注解：Spring MVC 在调用目标处理方法前，会先逐个调用在方法级上标注了@ModelAttribute 的方法
在方法的入参前使用 @ModelAttribute 注解：可以从隐含对象中获取隐含的模型数据中获取对象，再将请求参数 –绑定到对象中，再传入入参将方法入参对象添加到模型中

@RequestParam
在处理方法入参处使用 @RequestParam 可以把请求参 数传递给请求方法

@PathVariable
绑定 URL 占位符到入参

@ExceptionHandler
注解到方法上，出现异常时会执行该方法

@ControllerAdvice
使一个Contoller成为全局的异常处理类，类中用@ExceptionHandler方法注解的方法可以处理所有Controller发生的异常

四、自动匹配参数

      //match automatically
     @RequestMapping("/person")
     public String toPerson(String name,double age){
         System.out.println(name+" "+age);
         return "hello";
     }

五、自动装箱

1.编写一个Person实体类

 package test.SpringMVC.model;
 public class Person {
     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;
     }
     private String name;
     private int age;

 }

2.在Controller里编写方法

     //boxing automatically
     @RequestMapping("/person1")
     public String toPerson(Person p){
         System.out.println(p.getName()+" "+p.getAge());
         return "hello";
     }

六、使用InitBinder来处理Date类型的参数

     //the parameter was converted in initBinder
     @RequestMapping("/date")
     public String date(Date date){
         System.out.println(date);
         return "hello";
     }

     //At the time of initialization,convert the type "String" to type "date"
     @InitBinder
     public void initBinder(ServletRequestDataBinder binder){
         binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"),
                 true));
     }

七、向前台传递参数

      //pass the parameters to front-end
     @RequestMapping("/show")
     public String showPerson(Map<String,Object> map){
         Person p =new Person();
         map.put("p", p);
         p.setAge(20);
         p.setName("jayjay");
         return "show";
     }

八、使用Ajax调用

      //pass the parameters to front-end using ajax
     @RequestMapping("/getPerson")
     public void getPerson(String name,PrintWriter pw){
         pw.write("hello,"+name);
     }
     @RequestMapping("/name")
     public String sayHello(){
         return "name";
     }

      $(function(){
               $("#btn").click(function(){
                   $.post("mvc/getPerson",{name:$("#name").val()},function(data){
                       alert(data);
                   });
               });
           });

九、在Controller中使用redirect方式处理请求

      //redirect
     @RequestMapping("/redirect")
     public String redirect(){
         return "redirect:hello";
     }

十、文件上传

1.需要导入两个jar包

2.在SpringMVC配置文件中加入

     <!-- upload settings -->
     <bean id="multipartResolver"  class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
         <property name="maxUploadSize" value="102400000"></property>
     </bean>

3.方法代码

  @RequestMapping(value="/upload",method=RequestMethod.POST)
     public String upload(HttpServletRequest req) throws Exception{
         MultipartHttpServletRequest mreq = (MultipartHttpServletRequest)req;
         MultipartFile file = mreq.getFile("file");
         String fileName = file.getOriginalFilename();
         SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
         FileOutputStream fos = new FileOutputStream(req.getSession().getServletContext().getRealPath("/")+
                 "upload/"+sdf.format(new Date())+fileName.substring(fileName.lastIndexOf('.')));
         fos.write(file.getBytes());
         fos.flush();
         fos.close();

         return "hello";
     }

4.前台form表单

 <form action="mvc/upload" method="post" enctype="multipart/form-data">
           <input type="file" name="file"><br>
           <input type="submit" value="submit">
       </form>

十一、使用@RequestParam注解指定参数的name

 @Controller
 @RequestMapping("/test")
 public class mvcController1 {
     @RequestMapping(value="/param")
     public String testRequestParam(@RequestParam(value="id") Integer id,
             @RequestParam(value="name")String name){
         System.out.println(id+" "+name);
         return "/hello";
     }
 }

十二、Restful风格的SringMVC

1.RestController

 @Controller
 @RequestMapping("/rest")
 public class RestController {
     @RequestMapping(value="/user/{id}",method=RequestMethod.GET)
     public String get(@PathVariable("id") Integer id){
         System.out.println("get"+id);
         return "/hello";
     }

     @RequestMapping(value="/user/{id}",method=RequestMethod.POST)
     public String post(@PathVariable("id") Integer id){
         System.out.println("post"+id);
         return "/hello";
     }

     @RequestMapping(value="/user/{id}",method=RequestMethod.PUT)
     public String put(@PathVariable("id") Integer id){
         System.out.println("put"+id);
         return "/hello";
     }

     @RequestMapping(value="/user/{id}",method=RequestMethod.DELETE)
     public String delete(@PathVariable("id") Integer id){
         System.out.println("delete"+id);
         return "/hello";
     }

 }

2.form表单发送put和delete请求
　　在web.xml中配置:

  <!-- configure the HiddenHttpMethodFilter,convert the post method to put or delete -->
   <filter>
       <filter-name>HiddenHttpMethodFilter</filter-name>
       <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
   </filter>
   <filter-mapping>
       <filter-name>HiddenHttpMethodFilter</filter-name>
       <url-pattern>/*</url-pattern>
   </filter-mapping>

　　在前台的请求:

     <form action="rest/user/1" method="post">
         <input type="hidden" name="_method" value="PUT">
         <input type="submit" value="put">
     </form>

     <form action="rest/user/1" method="post">
         <input type="submit" value="post">
     </form>

     <form action="rest/user/1" method="get">
         <input type="submit" value="get">
     </form>

     <form action="rest/user/1" method="post">
         <input type="hidden" name="_method" value="DELETE">
         <input type="submit" value="delete">
     </form>

十三、返回json格式的字符串

1.导入以下jar包

2.方法代码

 @Controller
 @RequestMapping("/json")
 public class jsonController {

     @ResponseBody
     @RequestMapping("/user")
     public  User get(){
         User u = new User();
         u.setId(1);
         u.setName("jayjay");
         u.setBirth(new Date());
         return u;
     }
 }

十四、异常的处理

1.处理局部异常（Controller内）

     @ExceptionHandler
     public ModelAndView exceptionHandler(Exception ex){
         ModelAndView mv = new ModelAndView("error");
         mv.addObject("exception", ex);
         System.out.println("in testExceptionHandler");
         return mv;
     }

     @RequestMapping("/error")
     public String error(){
         int i = 5/0;
         return "hello";
     }

2.处理全局异常（所有Controller）

 @ControllerAdvice
 public class testControllerAdvice {
     @ExceptionHandler
     public ModelAndView exceptionHandler(Exception ex){
         ModelAndView mv = new ModelAndView("error");
         mv.addObject("exception", ex);
         System.out.println("in testControllerAdvice");
         return mv;
     }
 }

3.另一种处理全局异常的方法
　　在SpringMVC配置文件中配置:

     <!-- configure SimpleMappingExceptionResolver -->
     <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
         <property name="exceptionMappings">
             <props>
                 <prop key="java.lang.ArithmeticException">error</prop>
             </props>
         </property>
     </bean>

　　说明:error是出错页面

十五、设置一个自定义拦截器

1.创建一个MyInterceptor类，并实现HandlerInterceptor接口

 public class MyInterceptor implements HandlerInterceptor {
 @Override
     public void afterCompletion(HttpServletRequest arg0,
             HttpServletResponse arg1, Object arg2, Exception arg3)
             throws Exception {
         System.out.println("afterCompletion");
     }
 @Override
     public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
             Object arg2, ModelAndView arg3) throws Exception {
         System.out.println("postHandle");
     }
 @Override
     public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,
             Object arg2) throws Exception {
         System.out.println("preHandle");
         return true;
     }
 }

2.在SpringMVC的配置文件中配置

     <!-- interceptor setting -->
     <mvc:interceptors>
         <mvc:interceptor>
             <mvc:mapping path="/mvc/**"/>
             <bean class="test.SpringMVC.Interceptor.MyInterceptor"></bean>
         </mvc:interceptor>
     </mvc:interceptors>

3.拦截器执行顺序

十六、表单的验证（使用Hibernate-validate）及国际化

1.导入Hibernate-validate需要的jar包

2.编写实体类User并加上验证注解

 public class User {
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Date getBirth() {
         return birth;
     }
     public void setBirth(Date birth) {
         this.birth = birth;
     }
     @Override
     public String toString() {
         return "User [id=" + id + ", name=" + name + ", birth=" + birth + "]";
     }
     private int id;
     @NotEmpty
     private String name;
     @Past
     @DateTimeFormat(pattern="yyyy-MM-dd")
     private Date birth;
 }

说明:@Past表示时间必须是一个过去值

3.在jsp中使用SpringMVC的form表单

     <form:form action="form/add" method="post" modelAttribute="user">
         id:<form:input path="id"/><form:errors path="id"/><br>
         name:<form:input path="name"/><form:errors path="name"/><br>
         birth:<form:input path="birth"/><form:errors path="birth"/>
         <input type="submit" value="submit">
     </form:form> 

说明:path对应name

4.Controller中代码

 @Controller
 @RequestMapping("/form")
 public class formController {
     @RequestMapping(value="/add",method=RequestMethod.POST)
     public String add(@Valid User u,BindingResult br){
         if(br.getErrorCount()>0){
             return "addUser";
         }
         return "showUser";
     }

     @RequestMapping(value="/add",method=RequestMethod.GET)
     public String add(Map<String,Object> map){
         map.put("user",new User());
         return "addUser";
     }
 }

补充：

1.因为jsp中使用了modelAttribute属性，所以必须在request域中有一个"user".
2.@Valid 表示按照在实体上标记的注解验证参数
3.返回到原页面错误信息回回显，表单也会回显
5.错误信息自定义
　　在src目录下添加locale.properties

 NotEmpty.user.name=name can't not be empty
 Past.user.birth=birth should be a past value
 DateTimeFormat.user.birth=the format of input is wrong
 typeMismatch.user.birth=the format of input is wrong
 typeMismatch.user.id=the format of input is wrong

　　在SpringMVC配置文件中配置

 <!-- configure the locale resource -->
 <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
     <property name="basename" value="locale"></property>
 </bean>

6.国际化显示

　　在src下添加locale_zh_CN.properties

 username=账号
 password=密码

　　locale.properties中添加

 username=username
 password=password

　　创建一个locale.jsp

  <body>
     <fmt:message key="username"></fmt:message>
     <fmt:message key="password"></fmt:message>
  </body>

　　在SpringMVC中配置

  <!-- make the jsp page can be visited -->
  <mvc:view-controller path="/locale" view-name="locale"/>

　　让locale.jsp在WEB-INF下也能直接访问

　　最后，访问locale.jsp，切换浏览器语言，能看到账号和密码的语言也切换了

十七、整合SpringIOC和SpringMVC

1.创建一个test.SpringMVC.integrate的包用来演示整合，并创建各类

2.User实体类

 public class User {
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Date getBirth() {
         return birth;
     }
     public void setBirth(Date birth) {
         this.birth = birth;
     }
     @Override
     public String toString() {
         return "User [id=" + id + ", name=" + name + ", birth=" + birth + "]";
     }
     private int id;
     @NotEmpty
     private String name;
     @Past
     @DateTimeFormat(pattern="yyyy-MM-dd")
     private Date birth;
 }

3.UserService类

 @Component
 public class UserService {
     public UserService(){
         System.out.println("UserService Constructor...\n\n\n\n\n\n");
     }

     public void save(){
         System.out.println("save");
     }
 }

4.UserController类

 @Controller
 @RequestMapping("/integrate")
 public class UserController {
     @Autowired
     private UserService userService;

     @RequestMapping("/user")
     public String saveUser(@RequestBody @ModelAttribute User u){
         System.out.println(u);
         userService.save();
         return "hello";
     }
 }

5.Spring配置文件

　　在src目录下创建SpringIOC的配置文件applicationContext.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     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/util
         http://www.springframework.org/schema/util/spring-util-4.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd
         "
         xmlns:util="http://www.springframework.org/schema/util"
         xmlns:p="http://www.springframework.org/schema/p"
         xmlns:context="http://www.springframework.org/schema/context"
         >
     <context:component-scan base-package="test.SpringMVC.integrate">
         <context:exclude-filter type="annotation"
             expression="org.springframework.stereotype.Controller"/>
         <context:exclude-filter type="annotation"
             expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
     </context:component-scan>

 </beans>

　　在web.xml中添加配置

   <!-- configure the springIOC -->
   <listener>
       <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>
   <context-param>
     <param-name>contextConfigLocation</param-name>
     <param-value>classpath:applicationContext.xml</param-value>
   </context-param>

6.在SpringMVC中进行一些配置，防止SpringMVC和SpringIOC对同一个对象的管理重合

     <!-- scan the package and the sub package -->
     <context:component-scan base-package="test.SpringMVC.integrate">
         <context:include-filter type="annotation"
             expression="org.springframework.stereotype.Controller"/>
         <context:include-filter type="annotation"
             expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
     </context:component-scan>

十八、SpringMVC详细运行流程图

十九、SpringMVC运行原理

1. 客户端请求提交到DispatcherServlet
2. 由DispatcherServlet控制器查询一个或多个HandlerMapping，找到处理请求的Controller
3. DispatcherServlet将请求提交到Controller
4. Controller调用业务逻辑处理后，返回ModelAndView
5. DispatcherServlet查询一个或多个ViewResoler视图解析器，找到ModelAndView指定的视图
6. 视图负责将结果显示到客户端

二十、SpringMVC与struts2的区别

1、springmvc基于方法开发的，struts2基于类开发的。springmvc将url和controller里的方法映射。映射成功后springmvc生成一个Handler对象，对象中只包括了一个method。方法执行结束，形参数据销毁。springmvc的controller开发类似web service开发。
2、springmvc可以进行单例开发，并且建议使用单例开发，struts2通过类的成员变量接收参数，无法使用单例，只能使用多例。
3、经过实际测试，struts2速度慢，在于使用struts标签，如果使用struts建议使用jstl。