使用java代码操作redis
查询中使用redis逻辑
redis在增删改查中的使用
1. Java访问redis
2.1 添加依赖 <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.9.0</version> </dependency>
2.2 Java连接redis
Jedis jedis = new Jedis(ip, port); jedis.auth("123456");//权限认证 jedis.ping(); jedis.select(0);//切换数据库
Demo01
package com.zl; import redis.clients.jedis.Jedis; /** * @author zhuling * @site www.xiaomage.com * @company xxx公司 * @create 2019-10-13 19:25 * * * 讲解java代码操作redis * 包括string、hash、list * * 1、加载驱动 * 2、建立连接（url、uname、pwd） * 3、prepatestatement * 4、执行sql * 5、处理结果 * 6、关闭资源 * * * redis连接步骤 * 1、建立连接、连接后授权 * 2、使用redis * */ public class Demo1 { public static void main(String[] args) { Jedis jedis=new Jedis("192.168.142.128",6379); jedis.auth("123456"); System.out.println(jedis.ping()); /** * string */ // jedis.set("name","zs"); // jedis.set("age","22"); // System.out.println(jedis.get("name")); /** * hash */ // jedis.hset("user1","uname","ls"); // jedis.hset("user1","pwd","123456"); // jedis.hset("user1","set","nv"); // System.out.println(jedis.hget("user1", "uname")); // Map<String, String> user1 = jedis.hgetAll("user1"); // for (Map.Entry<String, String> entry : user1.entrySet()) { // System.out.println("key:" + entry.getKey() + ",value:" + entry.getValue()); // } /** * list left */ // jedis.lpush("hobby","a","b","c","d","e","f","g"); // System.out.println(jedis.lpop("hobby")); } }
DemoServerlet
package com.zl; 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 zhuling * @site www.xiaomage.com * @company xxx公司 * @create 2019-10-13 23:08 * * * redis 在项目中的使用 * 查询 * 增删改 */ @WebServlet("/list") public class DemoServlet 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("192.168.142.128",6379); jedis.auth("123456"); String bookList = jedis.get("bookList"); if(null==bookList ||"".equals(bookList)){ //查询数据库 String mysqlData="data"; //将mysqldata转成json数组串 jedis.set("booList",mysqlData); bookList = jedis.get("bookList"); req.setAttribute("msg","走了数据库拿数据"); req.setAttribute("bookList","boohList"); req.getRequestDispatcher("/bookList.jsp").forward(req,resp); }else{ req.setAttribute("msg","直接聪redis中取数据"); req.setAttribute("bookList","boohList"); req.getRequestDispatcher("/bookList.jsp").forward(req,resp); } } }
bookList
注意这一段 <%@ page isELIgnored="false" %>
<%-- Created by IntelliJ IDEA. User: 2018111801 Date: 2019/10/13 Time: 23:33 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> ${msg}:${bookList} </body> </html>