使用Java代码操作 Redis
Jedis简介
实际开发中，我们需要用Redis的连接工具连接Redis然后操作Redis，
对于主流语言，Redis都提供了对应的客户端；
提供了很多客户端 官方推荐的是Jedis 托管地址：https://github.com/xetorthio/jedis
要使用redis首先得下载pom依赖
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.9.0</version>
</dependency>
连接redis
Jedis jedis = new Jedis("192.168.234.131",6379);
jedis.auth("123456");
//jedis.close(); //使用完关闭连
System.out.println(jedis.ping());
使用Jedis连接池之后，在每次用完连接对象后一定要记得把连接归还给连接池。Jedis对close方法进行了改造，如果是连接池中的连接对象，调用Close方法将会是把连接对象返回到对象池，若不是则关闭连接。
操作Redis常用的三种数据类型 ，还有两种不常用的就不介绍了
package com.wp;
import redis.clients.jedis.Jedis;
/**
* @author 小李飞刀
* @site www.xiaomage.com
* @company zhuojing
* @create 2019-10-13 10:43
*/
public class javaDome {
public static void main(String[] args) {
//链接操作
Jedis jedis = new Jedis("192.168.234.131",6379);
jedis.auth("123456");
System.out.println(jedis.ping());
//操作字符串
jedis.set("aaa","张三");
System.out.println(jedis.get("aaa"));
//对哈希进行操作
jedis.hset("user1","uname","李四");
jedis.hset("user1","sex","男");
System.out.println(jedis.hgetAll("user1"));
System.out.println(jedis.hget("user1", "uname"));
//对list进行操作
jedis.lpush("hobby","a","b","c","d","e","f");
System.out.println(jedis.lpop("hobby"));
System.out.println(jedis.lpop("hobby"));
System.out.println(jedis.rpop("hobby"));
}
}
项目中的应用演示例子
查询中使用redis的逻辑
如图所示：
bookservlet.java
代码如下：
package web;
import redis.clients.jedis.Jedis;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
* @author 小李飞刀
* @site www.xiaomage.com
* @company zhuojing
* @create 2019-10-13 10:43
*/
@WebServlet("/wp")
public class Bookservlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req,resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
Jedis jedis = new Jedis("192.168.234.131",6379);
jedis.auth("123456");
String booklist = jedis.get("booklist");
if(booklist==null || "".equals(booklist)){
//模拟实际项目开发需求，在项目中运用redis
//查询数据库
String mysqldata="data";
//将mysqldata数据源转成json数组串
jedis.set("booklist",mysqldata);
booklist = jedis.get("booklist");
req.setAttribute("mag","走了数据库数据");
req.setAttribute("booklist",booklist);
req.getRequestDispatcher("/booklist.jsp").forward(req,resp);
}else{
req.setAttribute("mag","直接从redis里面拿了数据");
req.setAttribute("booklist",booklist);
req.getRequestDispatcher("/index.jsp").forward(req,resp);
}
}
}
index.jsp
<html>
<body>
<h2>Hello World!</h2>
<%--
Created by IntelliJ IDEA.
User: machenike
Date: 2019/10/13
Time: 11:53
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %>
<html>
<head>
<title>Title</title>
</head>
<body>
${mag}:${booklist}
</body>
</html>