Java代码实现文件下载

昨天晚上写了一篇文件上传的，今天上午把文件下载弄了一下，还是commons中的包

commons-fileupload.jar、commons-io.jar,下载位置就不说了,apache网站上找

这是一个web工程,下面有个截图

View Code

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DownLoadServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String path="D:/file";//资源位置
String fileName1 = request.getParameter("filename");
String fileName = new String(fileName1.getBytes("ISO-8859-1"),"utf-8");
File file = new File(path+"/"+fileName);//下载资源文件
//文件存在
if(file.exists()){
//设置响应类型及响应头
System.out.println(fileName);
response.setContentType("application/x-msdownload");
//防止输出文件名乱码以下两种均可
//response.setHeader( "Content-Disposition", "attachment;filename=\"" + new String( fileName.getBytes("gb2312"), "ISO8859-1" )+"\"");
response.addHeader("Content-Disposition", "attachment;filename=\""+URLEncoder.encode(fileName,"UTF-8")+"\"");
//读取文件
InputStream inputStream = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(inputStream);
byte[] bytes = new byte[1024];
ServletOutputStream outputStream = response.getOutputStream();//该对象可以在响应中写入二进制数据
BufferedOutputStream bos = new BufferedOutputStream(outputStream);
int readLength = 0;
while((readLength = bis.read(bytes))!=-1){
bos.write(bytes,0,readLength);
}
//释放资源
inputStream.close();
bis.close();
bos.flush();
outputStream.close();
bos.flush();
}
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}

}

好了，还有一点要注意，就是资源位置，我这里是在D盘创建了一个file文件夹，里面存存放几个测试文件就好了