SpringMVC入门

配置web.xml文件

前端控制器

DispatcherServlet:org.springframework.web.servlet.DispatcherServlet

<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

参数
类路径下的：classpath:springmvc.xml

    <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>
    <!--初始化参数-->
    <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>

配置springmvc.xml文件

开启注解的扫描

<context:component-scan base-package="cn"></context:component-scan>

视图解析器

<bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

自定义类型转换器

<bean id="conversionServiceFactoryBean" class="org.springframework.context.support.ConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="cn.utils.StringToConverter"></bean>
            </set>
        </property>
    </bean>

转换器类

public class StringToConverter implements Converter<String, Date> {
    /**
     *
     * @param source  传入的字符串
     * @return
     */
    @Override
    public Date convert(String source) {
        //判断
        if(source == null){
            throw new RuntimeException("请传入数据");
        }
        SimpleDateFormat dataFormat = new SimpleDateFormat("yyyy-MM-dd");

        try {
            //把字符串传换成日期
            return dataFormat.parse(source);
        } catch (ParseException e) {
           throw new RuntimeException(e);
        }
    }
}

前端控制器，哪些静态资源不拦截

    <mvc:resources location="/css/" mapping="/css/**"/>
    <mvc:resources location="/images/" mapping="/images/**"/>
    <mvc:resources location="/js/" mapping="/js/**"/>

开起springMVC框架注解的支持

 <mvc:annotation-driven conversion-service="conversionServiceFactoryBean"></mvc:annotation-driven>

注解

控制器
@Controller
路径的注解
@RequestMapping("/user")
@RequestMapping(path = "/hello")
@RequestMapping("/testRequestMapping")

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

    @RequestMapping(path = "/hello")
    public String sayHello(){
        System.out.println("hello springMVC");
        return "success";
    }
    // @RequestMapping(path = "/testRequestMapping")
    @RequestMapping("/testRequestMapping")
    //@RequestMapping(value = "/testRequestMapping",params = {"username==heihei"})
    //@RequestMapping(value = "/testRequestMapping",params = {"username"})
    //@RequestMapping(value = "/testRequestMapping",method = {RequestMethod.POST,RequestMethod.GET})
    public String testRequestMapping(){
        System.out.println("RequestMapping");
        return "success";
    }
}

常用注解

@Controller
@RequestMapping("/annotation")
@SessionAttributes(value = {"msg"})//存入Session中
public class AnnoController {
    /**
     * 当名字对应不上的时候  对应
     * @param name
     * @return
     */
    @RequestMapping("/testRequestParam")
    public String testRequestParam(@RequestParam("username") String name){
        System.out.println("ok");
        System.out.println(name);
        return "success";
    }

    /**
     * 获取到请求体的内容
     * @return
     */
    @RequestMapping("/testRequestBody")
    public String testRequestBody(@RequestBody String body){
        System.out.println("ok");
        System.out.println(body);
        return "success";
    }

    /**
     * PathVariable
     * @return
     */
    @RequestMapping(value = "/testPathVariable/{sid}")
    public String testPathVariable(@PathVariable(name = "sid") String id){
        System.out.println("ok");
        System.out.println(id);
        return "success";
    }

    /**
     * 获取请求头的值
     * @param header
     * @return
     */
    @RequestMapping("/testRequestHeader")
    public String testRequestHeader(@RequestHeader("Accept") String header){
        System.out.println("ok");
        System.out.println(header);
        return "success";
    }

    /**
     * 获取Cookie中的值
     * @param cookie
     * @return
     */
    @RequestMapping("/testCookieValue")
    public String testCookieValue(@CookieValue("JSESSIONID") String cookie){
        System.out.println("ok");
        System.out.println(cookie);
        return "success";
    }

    /**
     * testModelAttribute  放在有返回值方法上  或者  放在没有返回值方法上的
     * @return
     */
    @RequestMapping("/testModelAttribute")
    public String testModelAttribute(@ModelAttribute("abc") User user){
        System.out.println("testModelAttribute is ok");
        System.out.println(user);
        return "success";
    }

    /**
     * ModelAttribute
     * 方法优先执行
     * @return
     */
    /*
    @ModelAttribute
    public User ShowUser(String uname){
        System.out.println("showUser is ok");
        User user = new User();
        user.setUname(uname);
        user.setAge(10);
        user.setDate(new Date());
        return user;
    }
     */
    @ModelAttribute
    public void ShowUser(String uname, Map<String,User> map){
        System.out.println("showUser is ok");
        User user = new User();
        user.setUname(uname);
        user.setAge(10);
        user.setDate(new Date());
        map.put("abc",user);
    }

    /**
     * SessionAttributes  放在类上  把数据存如Session中   @SessionAttributes(value = {"msg"})
     * @return
     */
    @RequestMapping("/testSessionAttributes")
    public String testSessionAttributes(Model model){
        System.out.println("testSessionAttributes is ok");
        //底层存储到Request域中
        model.addAttribute("msg","美美");
        return "success";
    }
    @RequestMapping("/getSessionAttribute")
    public String getSessionAttribute(ModelMap modelMap,HttpServletRequest request){
        String msg = (String) modelMap.get("msg");
        System.out.println("modelMap:"+msg);
        String attribute = (String) request.getSession().getAttribute("msg");
        System.out.println("session:"+attribute);
        return "success";
    }

    /**
     * 清除Session中的数据
     * @param sessionStatus
     * @return
     */
    @RequestMapping("/deleteSessionAttribute")
    public String deleteSessionAttribute(SessionStatus sessionStatus){
       sessionStatus.setComplete();
        return "success";
    }

}

Response

请求转发

 @RequestMapping("/testVoid")
    public void testVoid(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("testVoid方法执行了...");
        // 编写请求转发的程序
        // request.getRequestDispatcher("/WEB-INF/pages/success.jsp").forward(request,response);

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

        // 设置中文乱码
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");

        // 直接会进行响应
        response.getWriter().print("你好");

        return;
    }

ModelAndView

 @RequestMapping("/testModelAndView")
    public ModelAndView testModelAndView(){
        // 创建ModelAndView对象
        ModelAndView mv = new ModelAndView();
        System.out.println("testModelAndView方法执行了...");
        // 模拟从数据库中查询出User对象
        User user = new User();
        user.setUsername("小凤");
        user.setPassword("456");
        user.setAge(30);

        // 把user对象存储到mv对象中，也会把user对象存入到request对象
        mv.addObject("user",user);

        // 跳转到哪个页面
        mv.setViewName("success");

        return mv;
    }

使用关键字的方式进行转发或者重定向

@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";
    }

文件上传
配置springmvc.xml文件解析对象
配置文件解析器对象，要求id名称必须是multipartResolver
三种文件上传的格式

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="10485760"></property>
    </bean>

/**
     * 文件上传
     * @return
     */
    @RequestMapping("/fileLoad1")
    public String fileLoad1(HttpServletRequest request) throws Exception {
        System.out.println("文件上传");
        //使用fileUpload组件
        String realPath = request.getSession().getServletContext().getRealPath("/uploads/");
        File file = new File(realPath);
        if(!file.exists()){
            file.mkdirs();
        }
        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);

        List<FileItem> fileItems = upload.parseRequest(request);
        for (FileItem fileItem : fileItems) {
            if(fileItem.isFormField()){
                //普通表单
            }else{
                //说明上传文件
                String fileItemName = fileItem.getName();
                fileItem.write(new File(realPath,fileItemName));
                fileItem.delete();
            }
        }

        return "success";
    }

    /**
     * SpringMVC文件上传
     * @return
     */
    @RequestMapping("/fileLoad2")
    public String fileLoad2(HttpServletRequest request, MultipartFile upload) throws IOException {
        System.out.println("SpringMVC方式的文件上传...");
        // 先获取到要上传的文件目录
        String path = request.getSession().getServletContext().getRealPath("/uploads");
        // 创建File对象，一会向该路径下上传文件
        File file = new File(path);
        // 判断路径是否存在，如果不存在，创建该路径
        if(!file.exists()) {
            file.mkdirs();
        }
        String filename = upload.getOriginalFilename();
        String uuid = UUID.randomUUID().toString().replaceAll("-", "").toUpperCase();
        // 把文件的名称唯一化
        filename = uuid+"_"+filename;
        // 上传文件
        upload.transferTo(new File(file,filename));
        return "success";

    }

    @RequestMapping("/fileLoad3")
    public String fileLoad3(HttpServletRequest request, MultipartFile upload) throws IOException {
        System.out.println("跨服务器方式的文件上传...");
        // 定义图片服务器的请求路径
        String path = "http://localhost:9090/day02_springmvc5_02image/uploads/";
        // 获取到上传文件的名称
        String filename = upload.getOriginalFilename();
        String uuid = UUID.randomUUID().toString().replaceAll("-", "").toUpperCase();
        // 把文件的名称唯一化
        filename = uuid+"_"+filename;
        // 向图片服务器上传文件
         // 创建客户端对象
        Client client = Client.create();
        // 连接图片服务器
        WebResource webResource = client.resource(path+filename);
        // 上传文件
        webResource.put(upload.getBytes());
        return "success";
    }

配置异常处理器
配置springmvc.xml的配置文件

    <bean id="sysExceptionResolver" class="cn.itcast.exception.SysExceptionResolver"></bean>

设置异常类

public class SysException extends Exception{
    private String message;

    @Override
    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public SysException(String message) {
        this.message = message;
    }
}

编写异常处理器
用ModelAndView对象把异常信息存储到域中

public class SysExceptionResolver implements HandlerExceptionResolver {
    /**
     * 处理异常的业务逻辑
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o
     * @param e
     * @return
     */
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        SysException exception = null;
        if(e instanceof SysException){
            exception = (SysException) e;
        }else {
            exception = new SysException("系统整在维护");
        }
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("errorMsg",exception.getMessage());
        modelAndView.setViewName("error");
        return modelAndView;
    }
}

配置拦截器
配置springmvc.xml的配置文件

<mvc:interceptors>
       <mvc:interceptor>
           <mvc:mapping path="/user/*"/>
           <bean class="cn.itcast.controller.demo1.MyInterceptor1"></bean>
       </mvc:interceptor>
       <mvc:interceptor>
           <mvc:mapping path="/**"/>
           <bean class="cn.itcast.controller.demo1.MyInterceptor2"></bean>
       </mvc:interceptor>
   </mvc:interceptors>

/**
 * 自定义拦截器1
 */
public class MyInterceptor1 implements HandlerInterceptor {
    /**
     * 预处理
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("拦截器执行了......前1");
        //response.sendRedirect(request.getContextPath()+"/error.jsp");
        return true;
    }

    /**
     * 后处理的方法   controller方法执行后执行  success.jsp执行之前
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("拦截器执行了......后1");
        //response.sendRedirect(request.getContextPath()+"/error.jsp");
    }

    /**
     * 在success.jsp方法后执行
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
   @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("拦截器执行了......最后1");
    }
}

/**
 * 自定义拦截器2
 */
public class MyInterceptor2 implements HandlerInterceptor {
    /**
     * 预处理
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("拦截器执行了......前2");
        //response.sendRedirect(request.getContextPath()+"/error.jsp");
        return true;
    }

    /**
     * 后处理的方法   controller方法执行后执行  success.jsp执行之前
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("拦截器执行了......后2");
        //response.sendRedirect(request.getContextPath()+"/error.jsp");
    }

    /**
     * 在success.jsp方法后执行
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
   @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("拦截器执行了......最后2");
    }
}