jsp文件下载代码示例,jsp 源码 下载

本文目录一览：

• 1、jsp实现文件的下载
• 2、用jsp怎么编写文件下载代码
• 3、jsp页面如何实现下载文档
• 4、JSP通过超链接下载文件

jsp实现文件的下载

%@pagelanguage=”java” import=”java.io.*,java.net.*” contentType=”application/x-msdownload” pageEncoding=”UTF-8″%%

//关于文件下载时采用文件流输出的方式处理：

//加上response.reset()，并且所有的％后面不要换行，包括最后一个；

String url = request.getParameter(“url”);

System.out.print(url);

int k = url.lastIndexOf(“\\”);

String url1=url.substring(k+1,url.length());

response.reset();//可以加也可以不加

response.setContentType(“application/x-download”);

String filedownload = url;

String filedisplay = url1;

filedisplay = URLEncoder.encode(filedisplay,”UTF-8″);

response.addHeader(“Content-Disposition”,”attachment;filename=” + filedisplay);

OutputStream outp = null;

FileInputStream in = null;

try

{

outp = response.getOutputStream();

in = new FileInputStream(filedownload);

byte[] b = new byte[1024];

int i = 0;

while((i = in.read(b)) 0)

{

outp.write(b, 0, i);

}

out.clear();

out = pageContext.pushBody();

outp.flush();

}

catch(Exception e)

{

System.out.println(“Error!”);

}

finally

{

if(in != null)

{

in.close();

in = null;

}

if(outp != null)

{

outp.close();

outp = null;

}

}

%

用jsp怎么编写文件下载代码

下面是我写的一个小例子,下载远程文件urlString,到本地文件localFile.

成功返回True,不成功返回False.

把这代码插入到你JSP中用到的地方就OK了:)

public boolean downLoadFile(String urlString, String localFile) {

URL url;

byte[] buffer = new byte[512];

int size = 0;

boolean success = false;

try {

url = new URL(urlString);

BufferedInputStream stream = new BufferedInputStream(url.openStream());

FileOutputStream fos = new FileOutputStream(localFile);

while ((size = stream.read(buffer)) != -1) {

fos.write(buffer, 0, size);

}

fos.close();

stream.close();

success = true;

}

catch (MalformedURLException e) {

e.printStackTrace();

}

catch (IOException e) {

e.printStackTrace();

}

return success;

}

jsp页面如何实现下载文档

jsp页面下载文档是在jsp中有一个a标签 ，当用户点击a标签的时候下载文件。

一般采用href属性直接指向一个服务器地址，只要链接的文件存在,就会给出弹出保存对话框.

点击a标签 先执行onclick事件，再请求href中指向的地址。

前端jsp：

a href=”#” onclick=”javascript:downloadtest(‘${app.id}’)” id=”pluginurl” style=”color: #83AFE2;text-decoration:underline;”/a

然后在js中：

function downloadtest(id){

var url = “%=request.getContextPath()%/app/download” + “/” + id;

$(“#pluginurl”).attr(“href”,url);

}

后台处理下载逻辑的java代码：

/**

* 下载文件

* @param id appid

* @param response

*/

@RequestMapping(value=”/download/{id}”)

public void download(@PathVariable String id, HttpServletResponse response){

String filepath = “”;

Result result = appService.getAppById(id);

App app = (App) result.getMap().get(“app”);

if(app == null){

return;

}

filepath = app.getUrl();

File file = new File(filepath);

InputStream inputStream = null;

OutputStream outputStream = null;

byte[] b= new byte[1024];

int len = 0;

try {

inputStream = new FileInputStream(file);

outputStream = response.getOutputStream();

response.setContentType(“application/force-download”);

String filename = file.getName();

filename = filename.substring(36, filename.length());

response.addHeader(“Content-Disposition”,”attachment; filename=” + URLEncoder.encode(filename, “UTF-8”));

response.setContentLength( (int) file.length( ) );

while((len = inputStream.read(b)) != -1){

outputStream.write(b, 0, len);

}

} catch (Exception e) {

e.printStackTrace();

}finally{

if(inputStream != null){

try {

inputStream.close();

inputStream = null;

} catch (IOException e) {

e.printStackTrace();

}

}

if(outputStream != null){

try {

outputStream.close();

outputStream = null;

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

JSP通过超链接下载文件

JSP页面点击超链接弹出文件下载，代码如下：

%

String path = request.getContextPath();

String basePath = request.getScheme()+”://”+request.getServerName()+”:”+request.getServerPort()+path+”/”;

%

//然后

a href =”%= basePath %/upload/aa.doc }” target=”_blank”下nbsp;nbsp;载/a

注：%= basePath %获取部署JSP项目的根目录，/upload/aa.doc/是根目录uploadaa.doc文件，根据需求修改即可。