SpringMVC 注解实现操作

一、SpringMVC基础入门，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

<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">                        <!-- 扫描这个包下的bean -->    <context:component-scan base-package="test.SpringMVC"/>    <!-- 不处理静态资源 -->    <mvc:default-servlet-handler />    <!-- 使用注解必须配置-->    <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 即可

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

public class Person {    private String name;    private int age;    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;    }     }

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"@InitBinderpublic 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";}

• 前台可在Request域中取到”p”

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";}

前台用下面的Jquery代码调用:

$(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>

在前台可以用以下代码产生请求

<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

@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）

@ExceptionHandlerpublic 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）

@ControllerAdvicepublic 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>

• 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;}

• @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>

• 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";    }}

• 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 emptyPast.user.birth=birth should be a past valueDateTimeFormat.user.birth=the format of input is wrongtypeMismatch.user.birth=the format of input is wrongtypeMismatch.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=user namepassword=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