文章摘要
这篇文章描述了一个Java Servlet类`DownloadOfIServlet`，实现了文件下载功能。在`doPost`方法中，代码通过`InputStream`和`OutputStream`从远程服务器读取文件并将其输出到客户端。它还使用了`BufferedInputStream`和`BufferedOutputStream`来优化读写性能，确保资源能够被正确关闭。核心内容是实现了一个简单的文件下载功能，通过网络流操作完成数据传输。
package cn.jbit.download.servlet;
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.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DownloadOfIOServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String basePath=request.getSession().getServletContext().getRealPath(“/upload”);
String filedisplay=”helloworld.jpg”;
String filedownload=basePath + File.separator + “helloworld.jpg”;
response.setContentType(“applicaiton/x-download”);
response.addHeader(“Content-Disposition”, “attachment;filename=”+filedisplay);
InputStream is=null;
OutputStream os=null;
BufferedInputStream bis=null;
BufferedOutputStream bos=null;
is=new FileInputStream(new File(filedownload));
bis=new BufferedInputStream(is);
os=response.getOutputStream();
bos=new BufferedOutputStream(os);
byte[] b=new byte[1024];
int len=0;
while((len=bis.read(b)) !=-1){
bos.write(b,0,len);
}
bis.close();
is.close();
bos.close();
os.close();
}
}