Spring MVC学习08文件上传

在POM文件中添加文件处理和文件上传的依赖

<!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.3</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.servlet</groupId>
                    <artifactId>jstl</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

编写Controller：

package com.yas.controller;

import org.apache.commons.io.FilenameUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.File;
import java.io.IOException;
import java.util.UUID;

@Controller
@RequestMapping("/upload")
public class UploadController {

    @RequestMapping("/test1")
    public String test1(MultipartFile source, HttpSession session, HttpServletRequest request, HttpServletResponse response) throws IOException {
        //获取文件信息
        String filename = source.getOriginalFilename();
        String contentType = source.getContentType();
        System.out.println(filename);
        System.out.println(contentType);

        String uniqueFilename = UUID.randomUUID().toString();
        String ext = FilenameUtils.getExtension(filename);

        //保存文件
        String realPath = session.getServletContext().getRealPath("/upload");
        source.transferTo(new File(realPath+"\\"+uniqueFilename+"."+ext));
        return "hello";

    }
}

编写自定义拦截器：

package com.yas.interceptor;

import org.apache.commons.fileupload.servlet.ServletRequestContext;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyFileUploadInterceptor implements HandlerInterceptor {
    private Long maxFileuploadSize;

    public Long getMaxFileuploadSize() {
        return maxFileuploadSize;
    }

    public void setMaxFileuploadSize(Long maxFileuploadSize) {
        this.maxFileuploadSize = maxFileuploadSize;
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //
        ServletRequestContext serverRequestConext = new ServletRequestContext(request);
        long l = serverRequestConext.contentLength();
        if (l > maxFileuploadSize) {
            throw new MaxUploadSizeExceededException(maxFileuploadSize);
        }
        return true;
    }
}

修改异常解析器：

package com.yas.resolver;

import com.yas.ex.MyException1;
import com.yas.ex.MyException2;
import com.yas.ex.MyException3;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//异常解析器
//任何一个hanlder中抛出异常时
public class MyExeceptionResolver implements HandlerExceptionResolver {
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        ModelAndView modelAndView = new ModelAndView();
        if(e instanceof MyException1){
            modelAndView.setViewName("error1");
        }else if(e instanceof MyException2){
            modelAndView.setViewName("error2");
        }else if (e instanceof MyException3){
            modelAndView.setViewName("error3");
        }else if(e instanceof MaxUploadSizeExceededException){
            modelAndView.setViewName("uploaderror");
        }
        return modelAndView;
    }
}

在mvc.xml中进行配置：

    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/upload/test1"></mvc:mapping>
            <bean class="com.yas.interceptor.MyFileUploadInterceptor">
                <property name="maxFileuploadSize" value="1048576"></property>
            </bean>
        </mvc:interceptor>
    </mvc:interceptors>

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
            <!-- 在tomcat 8中，此属性设置无效-->
            <!-- <property name="maxUploadSize" value="1048576"></property>-->
    </bean>

编写上传测试页面和错误提示页面：

upload.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <form action="${pageContext.request.contextPath}/upload/test1" method="post" enctype="multipart/form-data">
        <input type="file" name="source"><br>
        <input type="submit" value="上传">
    </form>
</body>
</html>

uploaderror.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    文件上传失败
</body>
</html>