Spring Mvc 文件下载Demo-优快云博客

本文介绍了使用SpringMVC框架实现文件下载的两种方法：传统Servlet API方式与现代Restful风格API方式。通过示例代码展示了如何配置并实现文件的下载功能。

传统代码：

@RequestMapping("file/download")
    public void fileDownload(HttpServletResponse response, HttpServletRequest request) {
        response.setCharacterEncoding("utf-8");
        response.setContentType("multipart/form-data");
        String path = request.getServletContext().getRealPath("static/style.css");
        response.setHeader("Content-Disposition", "attachment;fileName=style.css");
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            File file = new File(path);
            inputStream = new FileInputStream(file);
            outputStream = response.getOutputStream();
            byte[] b = new byte[1024];
            int length;
            while ((length = inputStream.read(b)) > 0) {
                outputStream.write(b, 0, length);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (outputStream != null) outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

既然用了Spring Mvc 就不应该出现j2ee的reponse的接口代码

java:

@RequestMapping("download")
    public ResponseEntity<byte[]> download() throws IOException {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        headers.setContentDispositionFormData("attachment", "upload.zip");
        File file = new File("d://upload.zip");
        return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file), headers, HttpStatus.CREATED);
    }

xml：

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
    <property name="messageConverters">  
        <list>  
            //把ByteArray加在Json前面  
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>  
            <bean id="jsonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" >  
                <property name = "supportedMediaTypes">  
                    <list>  
                        <value>text/plain;charset=UTF-8</value>  
                    </list>  
                </property>  
            </bean>  
        </list>  
    </property>  
</bean>