• SpringMVC 详解


    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/huskyking/p/5724939.html
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