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1. SpringMVC使用流程

1. 引入依赖

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <!--版本锁定-->
    <spring.version>5.0.2.RELEASE</spring.version>
</properties>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-web</artifactId>
  <version>${spring.version}</version>
</dependency>

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc</artifactId>
  <version>${spring.version}</version>
</dependency>

<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>servlet-api</artifactId>
  <version>2.5</version>
  <scope>provided</scope>
</dependency>

<dependency>
  <groupId>javax.servlet.jsp</groupId>
  <artifactId>jsp-api</artifactId>
  <version>2.0</version>
  <scope>provided</scope>
</dependency>

1. springmvc.xml配置文件

<?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.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描-->
    <context:component-scan base-package="cn.zh"></context:component-scan>

    <!--视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--文件的路径-->
        <property name="prefix" value="/WEB-INF/pages/"/>
        <!--需要解析的后缀名-->
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--配置自定义类型转换器-->
    <bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="cn.zh.utils.StringToDateConverter"></bean>
            </set>
        </property>
    </bean>

    <!--开启springMVC框架注解的支持-->
    <mvc:annotation-driven conversion-service="conversionService"/>

</beans>

1. web.xml配置

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>

  <servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--加载springMVC配置文件-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

  <!--配置解决中文乱码的过滤器-->
  <filter>
    <filter-name>characterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>


</web-app>

1. 注解方式使用springMVC

* RequestMapping注解
	* method:接收什么类型的请求
	* params:接收的参数中要有指定的属性
	* headers:必须包含对应的请求头

/**
 * 常用的注解
 */
@Controller
@RequestMapping("/anno")
@SessionAttributes(value = {"msg"}) //把msg=美美存入到session域对中
public class AnnoController {
    /**
     * 前台内容：
     * <a href="anno/testRequestParam?name=hehe">RequestParam</a>
     * @param username
     * @return
     */
    @RequestMapping("/testRequestParam")
    public String testRequestParam(@RequestParam(name = "name") String username){
        System.out.println("执行了。。。。。");
        return "success";
    }

    /**
     * 前台内容：
     *     <form action="anno/testRequestBody" method="post">
     *       用户姓名：<input type="text" name="username"><br>
     *       用户年龄：<input type="text" name="age"><br>
     *       <input type="submit" value="提交">
     *     </form>
     * 
     * 获取请求体
     * @param body
     * @return
     */
    public String testRequestBody(@RequestBody String body){
        System.out.println(body);
        return "success";
    }

    /**
     * 前台内容
     * <a href="anno/testPathVariable/10">testRequestParam</a>
     * PathVariable注解
     * @param id
     * @return
     */
    @RequestMapping(value = "/testPathVariable/{sid}",method = RequestMethod.POST)
    public String testPathVariable(@PathVariable(name = "sid") String id){
        System.out.println(id);
        return "success";
    }

    /**
     * 前台内容
     * <a href="anno/testRequestHeader">testRequestHeader</a>
     * 获取请求头
     * @param header
     * @return
     */
    @RequestMapping(value = "/testRequestHeader")
    public String testRequestHeader(@RequestHeader(value = "Accept") String header){
        System.out.println(header);
        return "success";
    }

    /**
     * 前台内容
     * <a href="anno/testCookieValue">testCookieValue</a>
     * 获取Cookie的值
     * @param cookieValue
     * @return
     */
    @RequestMapping(value = "/testCookieValue")
    public String testCookieValue(@CookieValue(value = "JSESSIONID") String cookieValue){
        System.out.println(cookieValue);
        return "success";
    }

    /**
     * 前台内容：
     *     <form action="anno/testModelAttribute" method="post">
     *       用户姓名：<input type="text" name="uname"><br>
     *       用户年龄：<input type="text" name="age"><br>
     *       <input type="submit" value="提交">
     *     </form>
     * ModelAttribute注解
     * @return
     */
    @RequestMapping(value = "/testModelAttribute")
    public String testModelAttribute(User user){
        System.out.println("testModelAttribute执行了.........");
        System.out.println(user);
        return "success";
    }

    /**
     * 该方法会先执行
     */
    @ModelAttribute
    public User showUser(String uname){
        System.out.println("showUser执行了..........");
        User user = new User();
        user.setUname(uname);
        user.setAge(20);
        user.setDate(new Date());
        return user;
    }

    /**
     * 前台内容
     * <a href="anno/testSessionAttributes">SessionAttributes</a>
     * SessionAttributes的注解
     * @return
     */
    @RequestMapping(value = "/testSessionAttributes")
    public String testSessionAttributes(Model model){
        System.out.println("testSessionAttributes...........");
        model.addAttribute("msg","cc");
        return "success";
    }

    /**
     * 前台内容
     * <a href="anno/getSessionAttributes">getSessionAttributes</a>
     * @param modelMap
     * @return
     */
    @RequestMapping(value = "/getSessionAttributes")
    public String getSessionAttributes(ModelMap modelMap){
        System.out.println("testSessionAttributes...........");
        Model msg = (Model) modelMap.get("msg");
        return "success";
    }

    /**
     * 前台内容
     *  <a href="anno/delSessionAttributes">delSessionAttributes</a>
     * @param status
     * @return
     */
    @RequestMapping(value = "/delSessionAttributes")
    public String delSessionAttributes(SessionStatus status){
        System.out.println("testSessionAttributes...........");
        status.setComplete();
        return "success";
    }
	
	/**
     * 前台页面
     * <a href="anno/testServlet">Servlet原生的api</a>
     * 获取原生的Servlet的api
     * @return
     */
    @RequestMapping("/testServlet")
    public String testServlet(HttpServletRequest request, HttpServletResponse response){
        System.out.println(request);
        HttpSession session = request.getSession();
        System.out.println(session);
        return "success";
    }
}

1. 自定义的类型转换器

public class StringToDateConverter implements Converter<String, Date> {
    /**
     * 将字符串转换为Date
     * @param s
     * @return
     */
    @Override
    public Date convert(String s) {
        //判断
        if (s == null){
            throw new RuntimeException("请您传入数据");
        }
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
        try {
            return df.parse(s);
        } catch (Exception e) {
            throw new RuntimeException("有错误！");
        }
    }
}

2. 响应方法

1. 配置前端控制器

<?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.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描-->
    <context:component-scan base-package="cn.zh"/>

    <!--视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--文件的路径-->
        <property name="prefix" value="/WEB-INF/pages/"/>
        <!--需要解析的后缀名-->
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--前端控制器，哪些静态资源不拦截-->
    <mvc:resources mapping="/js/**" location="/js/"/>
    <mvc:resources mapping="/images/**" location="/images/"/>
    <mvc:resources mapping="/css/**" location="/css/"/>

    <!--开启springMVC框架注解的支持-->
    <mvc:annotation-driven/>

</beans>

1. response的多种方式

@Controller
@RequestMapping("/user")
public class UserController {
    /**
     * 返回String
     * @param model
     * @return
     */
    @RequestMapping("/testString")
    public String testString(Model model){
        System.out.println("testString方法执行了........");

        User user = new User();
        user.setUsername("cc");
        user.setPassword("123");
        user.setAge(22);

        model.addAttribute("user",user);

        return "success";
    }

    /**
     * 无返回值
     * 请求转发一次请求，不用编写项目的名称
     * @param
     */
    @RequestMapping("/testVoid")
    public void testVoid(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("testVoid方法执行了........");
        //request.getRequestDispatcher("/WEB-INF/pages/success.jsp").forward(request,response);


        //response.sendRedirect(request.getContextPath()+"index.jsp");

        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        response.getWriter().print("你好，hello");

        return;
    }

    /**
     *
     * @return
     */
    @RequestMapping("/testModelAndView")
    public ModelAndView testModelAndView(){
        ModelAndView mv = new ModelAndView();

        System.out.println("testModelAndView方法执行了........");

        User user = new User();
        user.setUsername("cc");
        user.setPassword("123");
        user.setAge(22);

        mv.addObject("user",user);
        mv.setViewName("success");

        return mv;
    }

    /**
     * 使用关键字的方式进行转发或者重定向
     * @return
     */
    @RequestMapping("/testForwardOrRedirect")
    public String testForwardOrRedirect(){
        System.out.println("testForwardOrRedirect方法执行了........");


        //请求的转发
        //return "forward:/WEB-INF/pages/success.jsp";

        //重定向
        return "redirect:/index.jsp";
    }

    /**
     * 模拟异步请求和相应
     * @return
     */
    @RequestMapping("/testAjax")
    public @ResponseBody User testAjax(@RequestBody User user){
        System.out.println(user);
        //模拟查询数据库
        user.setUsername("ha");
        user.setAge(33);
        return user;
    }
}

3. 文件上传

1. springMVC.xml

<?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.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描-->
    <context:component-scan base-package="cn.zh"/>

    <!--视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--文件的路径-->
        <property name="prefix" value="/WEB-INF/pages/"/>
        <!--需要解析的后缀名-->
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--配置文件解析器-->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="10485760"></property>
    </bean>

    <!--前端控制器，哪些静态资源不拦截-->
    <mvc:resources mapping="/js/**" location="/js/"/>
    <mvc:resources mapping="/images/**" location="/images/"/>
    <mvc:resources mapping="/css/**" location="/css/"/>

    <!--开启springMVC框架注解的支持-->
    <mvc:annotation-driven/>

</beans>

1. 实现文件上传

@Controller
@RequestMapping("/user")
public class UserController {

    /**
     * 文件上传
     * @return
     */
    @RequestMapping("/fileUpload1")
    public String fileUpload1(HttpServletRequest request) throws Exception {
        System.out.println("文件上传");

        //使用fileupload组件完成文件上传
        //上传的位置
        String path = request.getSession().getServletContext().getRealPath("/uploads/");
        //判断该路径是否存在
        File file = new File(path);
        if (!file.exists()){
            file.mkdirs();
        }
        //解析request对象，获取文件上传
        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        //解析request
        List<FileItem> items = upload.parseRequest(request);
        //遍历
        for (FileItem item : items) {
            //判断当前的item对象是否是上传文件项
            if (item.isFormField()){
                //普通项
            }else {
                //文件项
                //获取上传文件的名称
                String filename = item.getName();
                String uuid = UUID.randomUUID().toString().replace("-", "");
                filename= uuid+"_"+filename;
                //完成文件上传
                item.write(new File(path,filename));
                //删除临时文件
                item.delete();
            }
        }

        return "success";
    }

    /**
     * spingMVC实现文件上传
     * @return
     */
    @RequestMapping("/fileUpload2")
    public String fileUpload2(HttpServletRequest request,MultipartFile upload) throws IOException {//upload和表单中的name要一样
        //上传的位置
        String path = request.getSession().getServletContext().getRealPath("/uploads/");
        //判断该路径是否存在
        File file = new File(path);
        if (!file.exists()){
            file.mkdirs();
        }
        //获取上传文件名称
        String filename = upload.getOriginalFilename();
        String uuid = UUID.randomUUID().toString().replace("-", "");
        filename= uuid+"_"+filename;
        //完成上传
        upload.transferTo(new File(path,filename));

        return "success";
    }

    /**
     * 跨服务器上传
     * @param upload
     * @return
     * @throws IOException
     */
    @RequestMapping("/fileUpload3")
    public String fileUpload3(MultipartFile upload) throws IOException {//upload和表单中的name要一样
        //定义上传文件服务器的路径
        String path = "http://localhost:9090/uploads/";

        //获取上传文件名称
        String filename = upload.getOriginalFilename();
        String uuid = UUID.randomUUID().toString().replace("-", "");
        filename= uuid+"_"+filename;
        //完成上传
        //创建客户端对象
        Client client = Client.create();
        //和图片服务器进行连接
        WebResource webResource = client.resource(path + filename);
        //上传文件
        webResource.put(upload.getBytes());
        return "success";
    }
}

4. 异常处理

1. springmvc.xml

<?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.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描-->
    <context:component-scan base-package="cn.zh"/>

    <!--视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--文件的路径-->
        <property name="prefix" value="/WEB-INF/pages/"/>
        <!--需要解析的后缀名-->
        <property name="suffix" value=".jsp"/>
    </bean>


    <!--前端控制器，哪些静态资源不拦截-->
    <mvc:resources mapping="/js/**" location="/js/"/>
    <mvc:resources mapping="/images/**" location="/images/"/>
    <mvc:resources mapping="/css/**" location="/css/"/>

    <!--配置异常处理器-->
    <bean id="sysExceptionResolver" class="cn.zh.exception.SysExceptionResolver"></bean>

    <!--开启springMVC框架注解的支持-->
    <mvc:annotation-driven/>

</beans>

1. 定义异常处理器

public class SysExceptionResolver implements HandlerExceptionResolver {

    /**
     * 处理异常业务逻辑
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @return
     */
    @Override
    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        SysException e = null;
        if (ex instanceof SysException){
            e = (SysException) ex;
        }else {
            e = new SysException("系统正在维护........");
        }
        //创建ModelAndView对象
        ModelAndView mv = new ModelAndView();
        mv.addObject("errorMsg",e.getMessage());
        mv.setViewName("error");
        return mv;
    }
}

5. 拦截器

1. springmvc.xml配置拦截器

<?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.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描-->
    <context:component-scan base-package="cn.zh"/>

    <!--视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--文件的路径-->
        <property name="prefix" value="/WEB-INF/pages/"/>
        <!--需要解析的后缀名-->
        <property name="suffix" value=".jsp"/>
    </bean>


    <!--前端控制器，哪些静态资源不拦截-->
    <mvc:resources mapping="/js/**" location="/js/"/>
    <mvc:resources mapping="/images/**" location="/images/"/>
    <mvc:resources mapping="/css/**" location="/css/"/>

    <!--配置拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--要拦截具体方法-->
            <mvc:mapping path="/user/*"/>
            <!--不要拦截的方法-->
            <!--<mvc:exclude-mapping path=""/>-->
            <!--配置拦截器对象-->
            <bean class="cn.zh.interceptor.MyInterceptor1"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

    <!--开启springMVC框架注解的支持-->
    <mvc:annotation-driven/>

</beans>

1. 拦截器实现

/**
 * 自定义拦截器
 */
public class MyInterceptor1 implements HandlerInterceptor {
    /**
     * 预处理,controller方法执行前
     * return true 放行，执行下一个拦截器，如果没有，执行controller中的方法
     * return false 不放行
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("执行了...");
        return true;
    }
}