• SpringMVC 示例实战教程

    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

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    <!--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

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    <?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

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    @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

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    //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

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    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

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    //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

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    //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

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    //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

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    //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

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    $(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

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    //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

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

    　　3.方法代码

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    @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

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    <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

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    @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

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    @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

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    <!-- 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

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    <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

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    @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）

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    @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）

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    @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

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    <!-- 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

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    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

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    <!-- 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

    (未选中不用导入)

    　　2.编写实体类User并加上验证注解

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    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;
    }

    　　ps:@Past表示时间必须是一个过去值

    　　3.在jsp中使用SpringMVC的form表单

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    <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>

    　　ps:path对应name

    　　4.Controller中代码

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    @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";
        }
    }

    　　ps:

    　　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

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    <!-- 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 name
password=password

    　　创建一个locale.jsp

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

    　　在SpringMVC中配置

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    <!-- 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、压轴大戏--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

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    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

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

    　　4.UserController

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    @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

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    <?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

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    <!-- 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

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    <!-- 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。
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  • 原文地址：https://www.cnblogs.com/zhangshitong/p/5341478.html
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