spring mvc 下载文件

spring mvc怎么下载图片呢?

有两种方式:

方式一:使用注解@responsebody

@responsebody  

    @requestmapping(value = "/download",produces="image/jpeg")  

    public byte[] downloadfile(httpservletrequest request, httpservletresponse response,string contenttype2,boolean isinline)  

            throws ioexception {  

        byte[]bytes=fileutils.getbytes4file("d:\\temp\\cc.jpg");  

//      response.addheader("content-disposition", downloadtype+";filename=\"a.jpg\"");  

        webservletutil.setdownloadcontentdisposition(isinline, "c.jpg", response);  

        return bytes;  

    }  

 webservletutil.setdownloadcontentdisposition 的实现如下:

/*** 

     * spring mvc下载文件设置的content-disposition 

     * @param isinline 

     * @param filename 

     * @return 

     */  

    public static string getcontentdisposition(boolean isinline,string filename){  

        string downloadtype=null;  

        if(isinline){  

            downloadtype=constant2.content_disposition_inline;  

        }else{  

            downloadtype=constant2.content_disposition_attachment;  

        }  

        if(valuewidget.isnullorempty(filename)){  

            filename="name_not_specified";  

        string format=downloadtype+";filename=\""+filename+"\"";  

        return format;  

    /*** 

     * 下载文件(或内联显示)时设置content-disposition 

     * @param response 

    public static void setdownloadcontentdisposition(boolean isinline,string filename, httpservletresponse response){  

        response.addheader(constant2.content_disposition, webservletutil.getcontentdisposition(isinline, filename));  

 注意:(1)一定要通过@requestmapping注解的produces 设置response 的content type;

(2)设置应答头时要使用addheader,而不是setheader

方式二:使用responseentity

@requestmapping(value = "/download3")  

    public responseentity<byte[]> download() throws ioexception {  

        httpheaders headers = new httpheaders();  

        headers.setcontenttype(mediatype.image_jpeg);  

//        headers.setcontentdispositionformdata("inline", "dict.jpg");//attachment  

        headers.set(constant2.content_disposition,webservletutil.getcontentdisposition(true, "dict.jpg"));  

        return new responseentity<byte[]>(fileutils.getbytes4file("d:\\temp\\cc.jpg"),  

                                          headers, httpstatus.created);  

     * favicon.ico  

     * @throws ioexception  

    @requestmapping(value = "/favicon.ico")  

    public responseentity<byte[]> faviconico(httpservletrequest request) throws ioexception {  

        headers.setcontenttype(mediatype.image_png);  

        string faviconiconame="sms-4.ico";  

        headers.set(constant2.content_disposition,webservletutil.getcontentdisposition(true, faviconiconame));  

        ///home/whuang/software/apache-tomcat-7.0.53/webapps/root/  

        string webapppath=null;  

        if(webservletutil.islocalip(request)){//服务器在本机(访问ip为127或localhost)  

            webapppath=webservletutil.getrealpath(request);  

            webapppath=dictionaryparam.get(constant2.dictionary_group_global_setting, "web-inf_loc");  

        return new responseentity<byte[]>(fileutils.getbytes4file(  

                webapppath  

                +"web-inf/static/img/"+faviconiconame),  

注意:不要使用headers.setcontentdispositionformdata 来设置content-disposition