servlet学习笔记（二）-Cookie

package com.tsinghua;

import java.io.*;

import javax.servlet.http.*;

public class CookieTest1 extends HttpServlet{

public void doGet(HttpServletRequest req,HttpServletResponse res){
try {
res.setContentType("text/html;charset=gbk");
PrintWriter pw=res.getWriter();
//当用户访问该servlet时，就将信息存储到cookie中

//1.先在服务器段创建一个cookie
Cookie myCookie=new Cookie("color1","red");

//2.该cookie存在的时间(如果不设置存在时间，Cookie将不会被保存)
myCookie.setMaxAge(30);

//3.将该cookie写回到客户端
res.addCookie(myCookie);

pw.println("已经创建了Cookie");

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public void doPose(HttpServletRequest req,HttpServletResponse res){
this.doGet(req,res);
}
}

package com.tsinghua;import java.io.*;import javax.servlet.http.*;public class CookieTest2 extends HttpServlet{public void doGet(HttpServletRequest req,HttpServletResponse res){try {res.setContentType("text/html;charset=gbk");PrintWriter pw=res.getWriter();//从客户端得到cookie信息Cookie
[]allCookie=req.getCookies();//如果Cookie不为空...if(allCookie!=null){//从中取出所有Cookiefor(int i=0;i<allCookie.length;i++){Cookie temp=allCookie[i];if(temp.getName().equals("color1")){String val=temp.getValue();pw.println("color1="+val);break;}if(i==allCookie.length)pw.println("不存在color1这个Cookie或者该Cookie已失效");}}else{pw.println("不存在color1这个Cookie或者该Cookie已失效");}}
catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public void doPose(HttpServletRequest req,HttpServletResponse res){this.doGet(req, res);}}