protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//使用response获得字节输出流
ServletOutputStream out=response.getOutputStream();
//获得服务器上面的图片
String realpath=this.getServletContext().getRealPath("456.png");
InputStream in=new FileInputStream(realpath);
int len=0;
byte[] buffer=new byte[1024];
while((len=in.read(buffer))>0){
out.write(buffer,0,len);
}
in.close();
out.close();
}
注意代码中采用了循环,是为了防止文件过大,而采用循环的方式逐步输出