play framework 下載圖片和pdf

在js中直接使用window.location.href 或者 window.open打開url 會在瀏覽器中直接開到文件（文件已經存在，不需要生成）
要實現在瀏覽器中下載的效果
java代碼

public static void downloadFile(Long id){
        DisposalUser disposalUser=DisposalUser.findById(id);
        String url=disposalUser.attachment_file.substring(1, disposalUser.attachment_file.length());
        String name=disposalUser.attachment_file.substring(disposalUser.attachment_file.lastIndexOf("/")+1, disposalUser.attachment_file.length());
        String[] type=name.split("\\.");
        File ff=new File(url);
        try {
            response.setHeader("Content-Disposition", "attachment;fileName="+URLEncoder.encode(type[0], "UTF-8")+"."+type[1]);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        renderBinary(ff);
    }

js代碼

$(".download-btn").die().live("click", function() {
    var attachment_file=$(this).attr("data-attachment-file");
    if(attachment_file==""){
        alert("文件不存在！");
        return;
    }
    var id=$(this).attr("data-id");
    window.location.href="/dispose/downloadFile?id="+id;
//  window.open("/dispose/downloadFile?id="+id)
});

另外一種 導出excel文件
在服務器上生成文件，然後下載到本地

public static void exportAllBlackList(Integer time,@Required @Min(1) Long ti, String query, @DateWithTime String st,
            @DateWithTime String et, @Min(1) Integer ps, @Min(1) Integer p, String sb,Integer so,Integer status,String ch,String fname
            ,String weibotype,String weiboname){
        if(time!=null&&time!=-1&&time!=0){
            JSONObject range = util.DateUtil.timeRanges(time);
            st = range.getString("st");
            et = range.getString("et");
        }
        if(sb==null){
            sb = "real_time";
        }
        if(so==null){
            so = -1;
        }
        String path = "public/check/";
        // 創建素材保存目錄
        File toSave = new File(path);
        if (!toSave.exists()) {
            toSave.mkdirs();
        }

        List<Map> result=new ArrayList<Map>();
        Groups group=Groups.findById(ti);
        String taskName=group.groupName;
        String fileName = path + sdf.format(new Date())+taskName.replace("#", "") + "-"+fname+".xls";

        HSSFWorkbook wb = new HSSFWorkbook();
        result=models.Account.getBlackDocList(query, st, et, ti, p, ps, sb, so,status,false);
        ForExcelWB(wb,result,weibotype,weiboname);
        try {
            FileOutputStream fout = new FileOutputStream(fileName);
            wb.write(fout);
            fout.flush();
            fout.close();
            fileName = "/" + fileName; // 修正下載路徑
            Operate.saveOperate(5, "導出全部的黑名單文章列表-["+ti+"]-"+fileName,getIp());
            renderJSON(ResultInfo.success(fileName, ""));
        } catch (Exception e) {
            e.printStackTrace();
            Logger.error(e.getMessage(),e);
            renderJSON(ResultInfo.error("導出失敗"));
        }
    }

js代碼

 export_all(ti,time,st,et,so,sb,"0,1,2",5,weibotype,weixintype,weiboname,weixinname,function(data){
                            $("body").removeClass("fcyshow");
                            if(data.result=="success"){
                                window.location.href=data.info.substring(0,data.info.lastIndexOf("/")+1)+encodeURIComponent(data.info.substring(data.info.lastIndexOf("/")+1,data.info.length));
                            }else{
                                alert(data.msg);
                            }
                      });