ssm文件上传下载比较详细的案例

背景：ssm框架

接下来，我会介绍单文件上传，下载，多文件的上传，下载，使用ajax进行文件的上传下载，和普通的表单提交的文件上传下载。

只要做项目，总是少不了文件的操作，好了废话不多说，直接上代码！

前提：需要在springmvc的配置文件里面加一个文件解析器，这个必须要有！！！

 <!-- 定义文件解释器 -->  
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">    
        <!-- 设置默认编码 -->  
        <property name="defaultEncoding" value="utf-8"></property>  
        <!-- 上传图片最大大小5M-->   
        <property name="maxUploadSize" value="5242440"></property>    
    </bean>  

随便提下：需要的jar包，我项目使用的maven构建，直接添加的依赖，jar包是下面两个：

　　commons-fileupload-1.3.2.jar
　　commons-io-2.2.jar

一、单文件的文件上传、下载

　　上传：前台

<form  id ="form2" action="load/upload2" enctype="multipart/form-data" method="post">
    <input type = "file" name= 'file' />
    <input type="text" name="name" value="dzf"/>
    <input type="button" id = "button2" value="ajax上传" onclick="fileupload2()">
    <input type ="submit" value="直接上传">
</form> 

function fileupload2(){
    var formData = new FormData($("#form2")[0]);
    $.ajax({
            url:'load/upload2',
            type:'post',
            data:formData,
            //必须false才会自动加上正确的Content-Type
            contentType: false,
            //必须false才会避开jQuery对 formdata 的默认处理
            //XMLHttpRequest会对 formdata 进行正确的处理
            processData: false,
            success:function(data){
                alert(data);
            },
            error:function(data){
                alert(data);
                alert("后台发生异常");
            },
            cache:false,
            async:true
        }); 
}

后台：

/**
     * 单个文件上传
     * @param request
     * @return
     */
    @RequestMapping(value="/upload2",produces="text/html;charset=utf-8")
    @ResponseBody
    private String upload2(@RequestParam("file")CommonsMultipartFile partFile,HttpServletRequest request) {
        try {
            String path = request.getServletContext().getRealPath("/upload");
            String name = request.getParameter("name");
            log.info("其他的参数{}",name);
            log.info("upload2---------------start---------------------");
            log.info("这个临时文件的路径是[{}]", path);
            String filename = partFile.getOriginalFilename();
            log.info("文件的名字：{}",filename);
            File file = new File(path+"/"+filename);
            InputStream inputStream = partFile.getInputStream();
            FileUtils.copyInputStreamToFile(inputStream, file);
            if(inputStream!=null){
                inputStream.close();
            }
            return "文件上传成功！";
        } catch (Exception e) {
            e.printStackTrace();
            return "文件上传失败！";
        } 
    }

下载：前台

<form action="load/down1" name="form3" id = "form3" method="post">
    <input type = "submit" value="普通文件下载">
</form>

后台：

/**
     * 文件下载
     * 单个文件下载
     * @param request
     * @return
     * @throws IOException 
     */
    @RequestMapping("/down1")
    private void down(HttpServletRequest request,HttpServletResponse response) throws IOException {
        String path = request.getServletContext().getRealPath("/upload");
        File file = new File(path);
        File[] files = file.listFiles();
        String name = files[0].getName();//随机获取一个文件，实际中按需编写代码
        System.out.println("文件的名字："+name);
        response.addHeader("content-disposition", "attachment;filename="+name);
        FileUtils.copyFile(files[0], response.getOutputStream());
    }

二、多文件的上传和下载

上传-前台：

<form  id ="form5" action="load/upload3" enctype="multipart/form-data" method="post">
    <input type = "file" name= 'file' />
    <input type = "file" name= 'file' />
    <input type = "file" name= 'file' />
    <input type="text" name="name" value="dzf"/>
    <input type="button" id = "button2" value="多文件ajax上传" onclick="fileupload3()">
    <input type ="submit" value="多文件直接上传">
</form> 

function fileupload3(){
    var formData = new FormData($("#form5")[0]);
        $.ajax({
                url:'load/upload3',
                type:'post',
                data:formData,
                //必须false才会自动加上正确的Content-Type
                contentType: false,
                //必须false才会避开jQuery对 formdata 的默认处理
                //XMLHttpRequest会对 formdata 进行正确的处理
                processData: false,
                success:function(data){
                    alert(data);
                },
                error:function(data){
                    alert(data);
                    alert("后台发生异常");
                },
                cache:false,
                async:true
            }); 
}

上传-后台：

/**
     * 多个文件上载
     * @param request
     * @return
     */
    @RequestMapping(value="/upload3",produces="text/html;charset=utf-8")
    @ResponseBody
    private String upload3(@RequestParam("file")CommonsMultipartFile[] partFiles,HttpServletRequest request) {
        InputStream inputStream = null;    
        try {
            String path = request.getServletContext().getRealPath("/upload");
            String name = request.getParameter("name");
            log.info("其他的参数{}",name);
            log.info("upload2---------------start---------------------");
            log.info("这个临时文件的路径是[{}]", path);
            for (int i = 0; i < partFiles.length; i++) {
                String filename = partFiles[i].getOriginalFilename();
                log.info("文件的名字：{}",filename);
                File file = new File(path+"/"+filename);
                inputStream = partFiles[i].getInputStream();
                FileUtils.copyInputStreamToFile(inputStream, file);
            }
            if(inputStream!=null){
                inputStream.close();
            }
            return "文件上传成功！";
        } catch (Exception e) {
            e.printStackTrace();
            return "文件上传失败！";
        } 
    }

一次性下载多个文件，我们需要把文件放到一个压缩包里去

下载-前台：

<form action="load/down2" name="form4" id = "form4" method="post">
    <input type = "submit" value="压缩文件下载">
</form>

下载-后台：

/**
     * 文件下载，一下次下载多个文件
     * 思路：先将多个文件压缩到一个压缩包里去，然后传到前台
     * @param request
     * @return
     * @throws IOException 
     */
    @RequestMapping("/down2")
    private void down2(HttpServletRequest request,HttpServletResponse response) throws IOException {
        String path = request.getServletContext().getRealPath("/upload");
        File file = new File(path);
        File[] files = file.listFiles();
        File zipFile =new File("test.zip");
        if(!zipFile.exists()){
            zipFile.createNewFile();
        }
        String zipName = zipFile.getName();
        log.info("压缩文件的名字：{}",zipName);
        response.addHeader("Content-Disposition", "attachment;filename="+zipName);
        //定义输出类型
//        response.setContentType("application/zip");
        ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(zipFile));
        BufferedInputStream in  =null;
        log.info("文件的个数{}",files.length);
        for(int i = 0;i<files.length;i++){
            String name = files[i].getName();
            System.out.println("文件的名字："+name);
            ZipEntry zipEntry = new ZipEntry(name);
            zip.putNextEntry(zipEntry);
            in = new BufferedInputStream(new FileInputStream(files[i]));
            int len = 0;
            byte [] btyes = new byte[1024*4];
            while((len=in.read(btyes))!=-1){
                zip.write(btyes, 0, len);
            }
        }
        zip.flush();
        zip.close();
        in.close();
        FileUtils.copyFile(zipFile, response.getOutputStream());
        if(zipFile.exists()){
            if(zipFile.delete()){
                log.info("压缩包删成功！！");
            }else{
                log.info("压缩包产出失败！！");
            }
            
        }
    }

到此，文件的上传、下载实例代码已经全部结束！