Java中如何操作Redis

这篇文章主要为大家展示了“Java中如何操作Redis”，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下“Java中如何操作Redis”这篇文章吧。

1.准备操作

 1.1 新建工程

1.2 sca-jedis工程依赖

  <dependencies>        <dependency>            <groupId>redis.clients</groupId>            <artifactId>jedis</artifactId>            <version>3.5.2</version>        </dependency>        <dependency>            <groupId>junit</groupId>            <artifactId>junit</artifactId>            <version>4.12</version>            <scope>test</scope>        </dependency>        <dependency>            <groupId>com.google.code.gson</groupId>            <artifactId>gson</artifactId>            <version>2.8.6</version>        </dependency>    </dependencies>

1.3 sca-tempalte工程依赖

 <dependencyManagement>        <dependencies>            <dependency>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-dependencies</artifactId>                <version>2.3.2.RELEASE</version>                <scope>import</scope>                <type>pom</type>            </dependency>        </dependencies>    </dependencyManagement>    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-redis</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>

1.4 测试是否可以连接Redis

package com.jt;import org.junit.Test;import redis.clients.jedis.Jedis;public class JedisTests {    @Test    public void testGetConnection(){        //假如不能连通,要注释掉redis.conf中 bind 127.0.0.1,        //并将protected-mode的值修改为no,然后重启redis再试        Jedis jedis=new Jedis("192.168.126.129",6379);        //jedis.auth("123456");//假如在redis.conf中设置了密码        String ping = jedis.ping();        System.out.println(ping);    }}

测试结果

注意保持一致：

1.5 修改redis.conf文件

/usr/local/docker/redis01/conf/目录下

修改配置文件之后需要重启，然后再测试连接 拓展:设定编译版本

2. 基于Jedis实现对redis中字符串的操作

@Test    public void testString01(){        //1.创建连接对象        Jedis jedis=new Jedis(ip,port);        //2.执行redis读写操作        //2.1想redis中存储字符串数据        jedis.set("id", "100");        jedis.expire("id", 2);        jedis.set("token", UUID.randomUUID().toString());        jedis.incr("id");        Map<String,Object> map=new HashMap<>();        map.put("code", "201");        map.put("name", "redis");        Gson gson=new Gson();        String jsonStr = gson.toJson(map);//将map对象转换为json字符串        jedis.set("lession",jsonStr);        //2.2删除数据        jedis.del("id");        //2.3获取数据        String id=jedis.get("id");        jsonStr=jedis.get("lession");        System.out.println(id);        System.out.println(jsonStr);        //3.释放资源        jedis.close();    }

3. 模式总结

==享元模式：==设计思想，通过池减少对象的创建次数，实现对象的可重用性，所有池的设计都有这个设计模式的应用
=例如整数池、字符串池、线程池、连接池

• AOP 代理模式

• Singleton 单例 HikariPool

• xxxAdapter 适配器模式

• Ribbon 策略

• RestTemplate 模板方法模式

• SL4J 门面

• Interceptor 执行链模式

• 工厂模式

4. 连接池JedisPool应用

package com.jt;import org.junit.                                                Test;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;import redis.clients.jedis.JedisPoolConfig;public class JedisPoolTests {    @Test    public void testJedisPool(){        //定义连接池配置        JedisPoolConfig config=new JedisPoolConfig();        //最大连接数        config.setMaxTotal(1000);        //最大空闲时间        config.setMaxIdle(60);        //创建连接池        JedisPool jedisPool=new JedisPool(config,"192.168.126.129",6379);        //从池中获取一个连接        Jedis resource = jedisPool.getResource();        //通过redis连接获取数据        resource.set("class", "cgb2107");        String aClass = resource.get("class");        System.out.println(aClass);        //释放资源        resource.close();//把连接还回去        jedisPool.close();    }}

连接池配置也可以不写，因为有默认的

5. 单例模式创建连接池

package com.jt;import com.jt.redis.JedisDataSource;import org.junit.Test;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;import redis.clients.jedis.JedisPoolConfig;public class JedisPoolTests {    @Test    public void testJedisPool(){        //单例模式创建连接池        Jedis resource = JedisDataSource.getConnection2();//        //定义连接池配置 可不写，有默认的//        JedisPoolConfig config=new JedisPoolConfig();//        //最大连接数//        config.setMaxTotal(1000);//        //最大空闲时间//        config.setMaxIdle(60);//        //创建连接池//        JedisPool jedisPool=new JedisPool(config,"192.168.126.129",6379);//        //从池中获取一个连接//        Jedis resource = jedisPool.getResource();//        通过redis连接获取数据        resource.set("class", "cgb2107");        String aClass = resource.get("class");        System.out.println(aClass);        //释放资源        resource.close();//把连接还回去        JedisDataSource.getJedisPool().close();    }}

package com.jt.redis;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;import redis.clients.jedis.JedisPoolConfig;public class JedisDataSource {    private static  volatile JedisPool jedisPool;    private static final String HOST="192.168.126.129";//将来写到配置中心    private static final Integer PORT=6379;    //饿汉式    static {        JedisPoolConfig jedisPoolConfig=new JedisPoolConfig();        jedisPoolConfig.setMaxTotal(16);        jedisPoolConfig.setMaxIdle(60);        jedisPool=new JedisPool(jedisPoolConfig,HOST,PORT);    }    public static Jedis getConnection(){        return jedisPool.getResource();    }    public static JedisPool getJedisPool(){        return jedisPool;    }    //懒汉式    public static Jedis getConnection2(){        if(jedisPool==null){            synchronized (JedisDataSource.class){                if(jedisPool==null){                    JedisPoolConfig jedisPoolConfig=new JedisPoolConfig();                    jedisPoolConfig.setMaxTotal(16);                    jedisPoolConfig.setMaxIdle(60);                    jedisPool=new JedisPool(jedisPoolConfig,HOST,PORT);//                    return jedisPool.getResource();                }            }        }        return jedisPool.getResource();    }}

拓展：volatile关键字

•  用来修饰属性、保证缓存一致性，但是不安全

• 保证其线程可见性 一个线程改了值，其他线程立刻可见

• 不能保证其原子性 不保证线程安全 不保证原子性

• 禁止指令重排序（例如count++…）

• 加锁synchronized可以保证原子性

• 在多线程的环境下会出现指令重排序的问题

6. 项目工程实践

6.1 分布式id

在分布式系统中，数据量将越来越大时，就需要对数据进行分表操作,但是,分表后，每个表中的数据都会按自己的节奏进行自增，很有可能出现ID冲突。这时就需要一个单独的机制来负责生成唯一ID，生成出来的ID也可以叫做 分布式ID

package com.jt.redis;import redis.clients.jedis.Jedis;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class IdGeneratorDemo1 {    public static Long getId(){//        Jedis jedis=new Jedis("192.168.126.129",6379);        Jedis jedis=JedisDataSource.getConnection();        Long id = jedis.incr("id");        jedis.close();        return id;    }    public static void main(String[] args) {        //构建最多只有3个线程的线程池        ExecutorService es= Executors.newFixedThreadPool(3);        for(int i=1;i<=10;i++){            //从池中取线程执行任务            es.execute(new Runnable() {//这个任务会存储到阻塞式任务队列中  阻塞队列.                @Override                public void run() {                    System.out.println(getId());                }            });        }    }}

6.2 单点登陆

package com.jt.redis;import redis.clients.jedis.Jedis;import java.util.UUID;public class SSODemo01 {    static  String token;    static Object doResource(String token){        //校验token是否为空        if(token==null){            throw new RuntimeException("请先登录");        }        //基于token查询redis数据,假如有对应数据说明用户登录了        Jedis jedis=JedisDataSource.getConnection();        String username = jedis.hget(token,"username");        if(username==null){            throw new RuntimeException("登录超时，请重新登录");        }        String permission = jedis.hget(token,"permission");        jedis.close();        if(!"sys-jedis-create".equals(permission)){            throw new RuntimeException("你没有权限访问");        }        return permission;    }    //执行登录认证、这样的业务写到认证服务器    static String doLoginin(String username,String password){        //1.校验数据的合法性（判定用户名、密码是否为空、密码长度...）       if(username==null||"".equals(username)) {           throw new RuntimeException("请输入用户名");       }       if(password==null||"".equals(password)) {           throw new RuntimeException("请输入密码");       }        //2.基于用户名查询用户信息，并判定密码是否正确        if(!"jack".equals(username)){            throw new RuntimeException("用户不存在");        }        if(!"123456".equals(password)){            throw new RuntimeException("密码不正确");        }        //3.用户存在且密码正确，将用户信息写入到redis        Jedis jedis=JedisDataSource.getConnection();        String token= UUID.randomUUID().toString();        jedis.hset(token,"username",username);        jedis.hset(token,"permission","sys-jedis-create");        jedis.close();        //4.将token信息返回给客户端        return token;    }    public static void main(String[] args) {        //1.登陆操作（用户身份认证）        token = SSODemo01.doLoginin("jack", "123456");        System.out.println(token);        //2.携带token访问资源服务器        Object o = doResource(token);        System.out.println(o);    }}

6.3 投票系统

package com.jt.redis;import redis.clients.jedis.Jedis;import javax.swing.text.html.HTMLEditorKit;import java.util.Set;public class VoteDemo01 {    //指定活动投票总数    static Long getCount(String activiryId ){        //1.建立连接        Jedis jedis=new Jedis("192.168.126.129",6379);        Long scard = jedis.scard(activiryId);        return scard;    }    //获取哪些人参与活动投票    static Object doGetMembers(String activiryId){        //1.建立连接        Jedis jedis=new Jedis("192.168.126.129",6379);        Set<String> smembers = jedis.smembers(activiryId);        return smembers;    }    //投票操作    static void doVote(String activiryId,String userId){        //1.建立连接        Jedis jedis=new Jedis("192.168.126.129",6379);        //2.执行投票        Boolean flag = jedis.sismember(activiryId, userId);        if(flag){            //投票过了再点就取消投票            jedis.srem(activiryId,userId);            System.out.println("取消投票");        }else {            //没投过票            jedis.sadd(activiryId,userId);            System.out.println("投票成功");        }        //3.释放资源        jedis.close();    }    public static void main(String[] args) {        String activiryId="101";        String userId="1";        String userId1="2";        String userId2="3";        doVote(activiryId,userId);        doVote(activiryId,userId1);        doVote(activiryId,userId2);        Long count = getCount(activiryId);        System.out.println(count);        Object o = doGetMembers(activiryId);        System.out.println(o);    }}

实现效果

7. StringRedisTemplate 应用

 7.1 修改yml文件

7.2 创建启动类

package com.jt;import org.junit.jupiter.api.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.data.redis.connection.RedisConnection;import org.springframework.data.redis.core.StringRedisTemplate;@SpringBootTestpublic class StringRedisTemplateTests {    @Autowired    private StringRedisTemplate redisTemplate;    @Test    void testGetConnection(){        RedisConnection connection = redisTemplate.getConnectionFactory().getConnection();        String ping = connection.ping();        System.out.println(ping);    }}

==StringRedisTemplate==

此对象可以实现与redis数据库的交互，存取数据的特点
会以字符串序列化的方式存储key/value
序列化/反序列化
狭义：序列化：1.将对象转化为字节 ；反序列化：将字节转化为对象
广义：序列化：对象→json式字符串或字节 反序列化：将字符串/字节→对象
实现效果

7.3 测试字符串读写

@Test//测试字符串读写    void testString01(){        //获取字符串对象        ValueOperations<String, String> vo = redisTemplate.opsForValue();        //2.读写rerdis数据        vo.set("name", "redis");        vo.set("author", "tony", Duration.ofSeconds(10));        String name = vo.get("name");        System.out.println(name);        String author = vo.get("author");        System.out.println(author);    }

拓展：lettuce

7.4 Hash类型读写

@Test//测试字符串读写    void testHash(){        //获取hash对象        HashOperations<String, Object, Object> vo = redisTemplate.opsForHash();        //2.读写rerdis数据        vo.put("blog", "id", "100");        vo.put("blog", "time", new Date().toString());        Object o = vo.get("blog", "id");        System.out.println(o);    }

8. RedisTemplate 应用

RedisTemplate是StringRedisTemplate 的父类
默认采用JDK的序列化、反序列化方式存取数据

package com.jt;import org.junit.jupiter.api.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.data.redis.core.RedisTemplate;import org.springframework.data.redis.core.ValueOperations;import java.time.Duration;@SpringBootTestpublic class RedisTemplateTests {    @Autowired    private RedisTemplate redisTemplate;    @Test    void testString01(){        //1.获取字符串对象        ValueOperations<String, String> vo = redisTemplate.opsForValue();        //2.读写rerdis数据        vo.set("name", "redis");        vo.set("author", "tony", Duration.ofSeconds(10));        String name = vo.get("name");        System.out.println(name);        String author = vo.get("author");        System.out.println(author);    }}

修改序列化方式

redisTemplate.setKeySerializer(RedisSerializer.string());

以上是“Java中如何操作Redis”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注编程网行业资讯频道！