jQuery.ajax servlet返回文件 [英] jQuery.ajax servlet return a file

问题描述

我对jQuery和ajax还是很陌生，我有一个问题. 在一个jsp中，我叫

I'm pretty new to jQuery and ajax and i have a question. In a jsp I call

function downloadDocument(documentId){
    var action = "attachment.do";
    var method = "downloadDocument";
    var url = action + "?actionType="+method+"&documentId=" + documentId;
    $.ajax({
          url: url,
          dataType: "json",
          type: 'POST',
          success: function(data){
              alert("downloaded!");
          },
          error: function (request, status, error) {
              alert(request.responseText);
            }
    });

然后在servlet中完成

then in the servlet I do

public void downloadDocument(ActionMapping mapping, ActionForm actionForm, HttpServletRequest request, HttpServletResponse response) throws IOException{

    AttachmentActionForm form = (AttachmentActionForm)actionForm;

    ServletOutputStream out = response.getOutputStream();

    try{
        // Get the downloadFileName, the name of the file when it will be downloaded by user
        String downloadFileName = "hello.txt";

        String  mimetype = "application/x-download"

        // Get the byte stream of the file
        FileInputStream in = new FileInputStream(Global.ATTACHMENTS_SHARED_FOLDER_PATH + downloadFileName);

        // Print out the byte stream
        byte[] buffer = new byte[4096];
        int length;
        while ((length = in.read(buffer)) > 0){
            out.write(buffer, 0, length);
        }

        response.addHeader("Content-Disposition", "attachment; filename="+downloadFileName);
        response.setHeader("Content-Length", Integer.toString(length));
        response.setContentType(mimetype);  

        in.close();
    }
    catch(Exception e){
        response.setContentType("text/text;charset=utf-8");
        response.setHeader("cache-control", "no-cache");
        System.out.println(e.getMessage());
        out.println(e.getMessage());
    }finally{
        out.flush();
    }
}

但是在ajax函数中，即使消息由文件内部的字符串组成，我也始终无法获得成功.我该怎么办?

But in the ajax function, I never get a success, all the time I get the error message, even if the message is composed by the string inside of the file. What can I do?

推荐答案

不要使用Ajax调用，//不要使用隐藏表单方法

dont use Ajax call use //use hidden form approach

<form action='../servletname' method='POST' id='formid'>
                <input type='hidden' value='' name='name' id='id'/>
                <input type='hidden' value=' ' name='name'  id='id' />
            </form>

点击按钮提交表单

$('#formid').submit(); 

在servlet中

response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment; filename=filnemae.fileformat");

 ServletOutputStream out = res.getOutputStream();

写输出流，然后关闭或刷新

write on ouput stream then close or flush

如果您通过server.xml中的post update postsize发送大数据

if you are sending large data through post update postsize in server.xml

这篇关于jQuery.ajax servlet返回文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！