jsp文件下載代碼示例,jsp 源碼 下載

本文目錄一覽：

• 1、jsp實現文件的下載
• 2、用jsp怎麼編寫文件下載代碼
• 3、jsp頁面如何實現下載文檔
• 4、JSP通過超鏈接下載文件

jsp實現文件的下載

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

//關於文件下載時採用文件流輸出的方式處理：

//加上response.reset()，並且所有的％後面不要換行，包括最後一個；

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怎麼編寫文件下載代碼

下面是我寫的一個小例子,下載遠程文件urlString,到本地文件localFile.

成功返回True,不成功返回False.

把這代碼插入到你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頁面如何實現下載文檔

jsp頁面下載文檔是在jsp中有一個a標籤 ，當用戶點擊a標籤的時候下載文件。

一般採用href屬性直接指向一個服務器地址，只要鏈接的文件存在,就會給出彈出保存對話框.

點擊a標籤 先執行onclick事件，再請求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

然後在js中：

function downloadtest(id){

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

$(“#pluginurl”).attr(“href”,url);

}

後台處理下載邏輯的java代碼：

/**

* 下載文件

* @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通過超鏈接下載文件

JSP頁面點擊超鏈接彈出文件下載，代碼如下：

%

String path = request.getContextPath();

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

%

//然後

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

註：%= basePath %獲取部署JSP項目的根目錄，/upload/aa.doc/是根目錄uploadaa.doc文件，根據需求修改即可。