负载均衡NGINX+redis实现SESSION共享

    网上的例子，没搜索到JAVA的，看到C#什么的，感觉挺奇怪的，就正好自己借助别人的思路用JAVA实现

   SESSION共享实现的方法，我选择了COOKIE，当然其他方法比如说，中间服务器，或者制定一个SESSION规则，将哪个SEESION分配到哪个服务器。选择COOKIE实现，最主要是方便，同时也有我现在做的是ERP系统，对于并发没有太多要求。

   NGINX的负载均衡，去官网http://nginx.org/  下载，现在对于很多开源JAR包或者工具下载，建议去官网，因为有最新的文档和介绍，比国内网盘存的东西，认识更加清晰

   负载均衡最基本的设置，在nginx.conf里面设置，我sheng'l

upstream mytomcats {

server 127.0.0.1:8080;

server 127.0.0.1:8081;

server 127.0.0.1:8082;
}

  server {
        listen       8088;
        server_name  localhost;shengl

...........
    }

   这是没有设置会话固定，设置了的话，SESSION的测试很难测试了。

   Redis是Key，Value的数据库，当成一个数据库就好了，主要是速度快。并且容易装和使用

   JAVA代码实现的核心就是判断是否已经有COOKIE的SESSIONID值，没有COOKIE中的值就SET进去，讲的很很粗糙，具体测试代码如下，测一下就很明白了。

   info.java

package htd;

import java.io.IOException;
import java.util.Set;

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

import redis.clients.jedis.Jedis;

/**
* Servlet implementation class hzm
*/
public class info extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* Default constructor.
*/
public info() {
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
Jedis jedis = new Jedis("localhost");
String sessionId=null;
//判断COOKIE是否存了SessionId
Cookie[] cookeArray=request.getCookies();
for(Cookie cookie:cookeArray){
if(cookie.getName().equals("sessionId")){
System.out.println("找到了"+sessionId);
sessionId=cookie.getValue();
}
}
if(sessionId==null){
System.out.println("找不到");
sessionId=request.getSession().getId();
}
Set<String> test=jedis.zrange(sessionId, 0, 3);
response.getWriter().write("{data:"+test.toString()+",seesionId:"+sessionId+"}");
response.getWriter().write("{place:"+request.getRealPath("\\")+"}");

jedis.close();
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}

   login.java

  

package htd;

import java.io.IOException;
import java.util.Set;

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

import redis.clients.jedis.Jedis;

/**
* Servlet implementation class login
*/
public class login extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public login() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub

String sessionId=null;
//判断COOKIE是否存了SessionId
Cookie[] cookeArray=request.getCookies();
for(Cookie cookie:cookeArray){
if(cookie.getName().equals("sessionId")){
sessionId=cookie.getValue();
}
}
if(sessionId==null){
sessionId=request.getSession().getId();
Cookie cookie = new Cookie("sessionId",sessionId);
cookie.setPath("/");
response.addCookie(cookie);
}
Jedis jedis = new Jedis("localhost");
Set<String> test=jedis.zrange(sessionId, 0, 3);
if(test==null||test.isEmpty()){
System.out.println("set一次=============");
String userName = request.getParameter("userName");
String password = request.getParameter("password");
String value = request.getParameter("value");
jedis.zadd(sessionId, 1,userName);
jedis.zadd(sessionId, 2,password);
jedis.zadd(sessionId, 3,value);
test=jedis.zrange(sessionId, 0, 3);
}

response.getWriter().write(test.toString()+"sessionID:"+sessionId);;
response.getWriter().write("{place:"+request.getRealPath("\\")+"}");
jedis.expire(sessionId,600);
jedis.close();

}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}

     web.xml配置SERVLET

      

<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>info</servlet-name>
<display-name>info</display-name>
<description></description>
<servlet-class>htd.info</servlet-class>
</servlet>
<servlet>
<servlet-name>login</servlet-name>
<display-name>login</display-name>
<description></description>
<servlet-class>htd.login</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>info</servlet-name>
<url-pattern>/info</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>

</web-app>

      index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="/htd/resources/jquery-3.1.1.min.js"></script>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<script>
function getCookie(name)
{
var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
if(arr=document.cookie.match(reg))
return unescape(arr[2]);
else
return null;
}
function getHt(){
$.ajax({
type: "GET",
url: "/htd/info",
success: function(data){
$("#t1").text("t1=="+data);
}
});
}
getHt();
function submit(){
$.ajax({
type: "GET",
url: "/htd/login",
data: {userName:$('#userName').val(),
password:$('#password').val(),
value:$('#value').val()},
success: function(data){
$("#t2").text("t2=="+data);
getHt();
}
});
}

</script>
<body>

<input id="userName" name="userName" id="userName" type="text">userId</input>
<input id="password" name="password" id="password" type="text">password</input>
<input id="value" name="value" id="value" type="text">value</input>
<input id="but1" type="button" value="sub" onclick="javascript:submit();"/>
<p id="t1"></p>
<p id="t2"></p>
</body>
</html>

       前台测试结果