servlet跳转更新

package cn.csdn.servlet;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
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 DemoServlet extends HttpServlet {

//发送的是get请求 ,交给这个Servlet的 doGet方法处理
//发送的是post请求,交给这个Servlet的doPost方法处理
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("你发送的是get请求处理");

}

//下载数据
public void download(HttpServletResponse response)
throws FileNotFoundException, IOException {
//设置响应的头信息 使响应的数据位图片的类型的操作
//http_imgload.jpg
//读取图片
//InputStream is = new FileInputStream(this.getServletContext().getRealPath("./images/http_imgload.jpg"));
InputStream is = new FileInputStream("D:\\NCode\\myeclipse\\workspace\\20111013\\WebRoot\\images\\http_imgload.jpg");
//设置响应的头信息
response.setHeader("Content-Disposition", "attachment;filename=a.jpg");
//得到输出流
OutputStream os = response.getOutputStream();
//怎么样写
byte n[]=new byte[1024];
int flag=0;
while( (flag = is.read(n))!=-1){
os.write(n, 0, flag);
}
os.close();
is.close();
}

//回送数据的类型
public void contentType(HttpServletResponse response)
throws FileNotFoundException, IOException {
//设置响应的头信息 使响应的数据位图片的类型的操作
//http_imgload.jpg
//读取图片
System.out.println();
//InputStream is = new FileInputStream(this.getServletContext().getRealPath("./images/http_imgload.jpg"));
InputStream is = new FileInputStream("D:\\NCode\\myeclipse\\workspace\\20111013\\WebRoot\\images\\http_imgload.jpg");
System.out.println(is);
//设置响应的头信息
response.setHeader("Content-Type", "image/jpeg");
//得到输出流
OutputStream os = response.getOutputStream();
//怎么样写
byte n[]=new byte[1024];
int flag=0;
while( (flag = is.read(n))!=-1){
os.write(n, 0, flag);
}
os.close();
is.close();
}

public void refresh(HttpServletResponse response) {
//定时刷新界面
response.setHeader("Refresh", "2;url=http://www.baidu.com");
}

public void redirect(HttpServletResponse response) {
//重定向
response.setStatus(302);
response.setHeader("location", "./index.html");
}

}