使用java代码操作redis
使用 java 代码操作 Redis
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>
1 <?xml version="1.0" encoding="UTF-8"?> 2 3 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <modelVersion>4.0.0</modelVersion> 6 7 <groupId>com.yuan</groupId> 8 <artifactId>redis01</artifactId> 9 <version>1.0-SNAPSHOT</version> 10 <packaging>war</packaging> 11 12 <name>redis01 Maven Webapp</name> 13 <!-- FIXME change it to the project's website --> 14 <url>http://www.example.com</url> 15 16 <properties> 17 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 18 <maven.compiler.source>1.7</maven.compiler.source> 19 <maven.compiler.target>1.7</maven.compiler.target> 20 </properties> 21 22 <dependencies> 23 <dependency> 24 <groupId>junit</groupId> 25 <artifactId>junit</artifactId> 26 <version>4.12</version> 27 <scope>test</scope> 28 </dependency> 29 <dependency> 30 <groupId>redis.clients</groupId> 31 <artifactId>jedis</artifactId> 32 <version>2.9.0</version> 33 </dependency> 34 </dependencies> 35 36 <build> 37 <finalName>redis01</finalName> 38 <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> 39 <plugins> 40 <plugin> 41 <artifactId>maven-clean-plugin</artifactId> 42 <version>3.1.0</version> 43 </plugin> 44 <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> 45 <plugin> 46 <artifactId>maven-resources-plugin</artifactId> 47 <version>3.0.2</version> 48 </plugin> 49 <plugin> 50 <artifactId>maven-compiler-plugin</artifactId> 51 <version>3.8.0</version> 52 </plugin> 53 <plugin> 54 <artifactId>maven-surefire-plugin</artifactId> 55 <version>2.22.1</version> 56 </plugin> 57 <plugin> 58 <artifactId>maven-war-plugin</artifactId> 59 <version>3.2.2</version> 60 </plugin> 61 <plugin> 62 <artifactId>maven-install-plugin</artifactId> 63 <version>2.5.2</version> 64 </plugin> 65 <plugin> 66 <artifactId>maven-deploy-plugin</artifactId> 67 <version>2.8.2</version> 68 </plugin> 69 </plugins> 70 </pluginManagement> 71 </build> 72 </project>
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
package com.yuan;import redis.clients.jedis.Jedis;
import java.util.Map;
/**
- 讲解 java 代码操作 redis
- String、hash、list
- 1、加载驱动
- 2、建立连接（url/uname/pwd）
- 3、preparestatement
- 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) {
//连接 redis
Jedis jedis = new Jedis("192.168.238.129",6379);
jedis.auth("123456");
System.out.println(jedis.ping());}}
2.3 Java 操作 redis
string（字符串）hash（哈希）
list（列表）
注 1：不需要记得 API 的方法，只需要查 redis 命令
package com.yuan;import redis.clients.jedis.Jedis;
import java.util.Map;
/**
- 讲解 java 代码操作 redis
- String、hash、list
- 1、加载驱动
- 2、建立连接（url/uname/pwd）
- 3、preparestatement
- 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) {
//连接 redis
Jedis jedis = new Jedis("192.168.238.129",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","sex","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());
// }<span style="color: rgba(0, 128, 0, 1)">/*</span><span style="color: rgba(0, 128, 0, 1)"> list </span><span style="color: rgba(0, 128, 0, 1)">*/</span>// jedis.lpush("hobby","a","b","c","d","e","f","g");
// System.out.println(jedis.lpop("hobby"));
// System.out.println(jedis.rpop("hobby"));
}
}
1 package com.yuan; 2 3 import redis.clients.jedis.Jedis; 4 5 import javax.servlet.ServletException; 6 import javax.servlet.annotation.WebServlet; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10 import java.io.IOException; 11 12 13 @WebServlet("/list") 14 public class DemoServlet extends HttpServlet { 15 @Override 16 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 17 doPost(req,resp); 18 } 19 20 @Override 21 protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 22 // 首页第一次是读取数据库，后面读取缓存（在没有增删改的情况） 23 //首页第一次是读取数据库，后面读取缓存 24 Jedis jedis=new Jedis("192.168.47.129",6379); 25 jedis.auth("123456"); 26 27 String booklist = jedis.get("booklist"); 28 if(booklist==null || "".equals(booklist)){ 29 //查询数据库 30 String mysqlData="data"; 31 //将 mysqldata 转成 json 数组串 32 jedis.set("booklist",mysqlData); 33 booklist = jedis.get("booklist"); 34 //第一次登录，访问数据库 35 req.setAttribute("mag","从数据库拿数据"); 36 req.setAttribute("booklist",booklist); 37 req.getRequestDispatcher("/booklist.jsp").forward(req,resp); 38 }else{ 39 //从缓存获取当前信息 40 req.setAttribute("mag","直接从 redis 中取得数据"); 41 req.setAttribute("booklist",booklist); 42 req.getRequestDispatcher("/booklist.jsp").forward(req,resp); 43 } 44 } 45 }
booklist.jsp 代码
1 <%-- 2 Created by IntelliJ IDEA. 3 User: 刘源 4 Date: 2019/10/14 5 Time: 1:52 6 To change this template use File | Settings | File Templates. 7 --%> 8 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 9 <%@ page isELIgnored="false" %> 10 <html> 11 <head> 12 <title>Title</title> 13 </head> 14 <body> 15 ${mag}:${booklist} 16 </body> 17 </html>