Java连接Redis

Jedis连接Redis,Lettuce连接Redis

Jedis连接Redis

1. 创建maven项目

2. 引入依赖

  <dependencies>

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>4.11</version>

      <scope>test</scope>

    </dependency>

    <dependency>

      <groupId>redis.clients</groupId>

      <artifactId>jedis</artifactId>

      <version>2.9.0</version>

    </dependency>

    <dependency>

      <groupId>org.projectlombok</groupId>

      <artifactId>lombok</artifactId>

      <version>1.18.12</version>

    </dependency>

  </dependencies>

3. 测试

  @Test

  public void Test1() {

//    连接Redis

    Jedis jedis = new Jedis("localhost", 6379);

//    操作Redis - 因为Redis命令是什么,Jedis方法就是什么

    jedis.set("name", "李四");

//    释放资源

    jedis.close();

    System.out.println(jedis.get("name"));

  }

Jedis如何存储一个对象到Redis

准备一个User实体类

@Data

@AllArgsConstructor

@NoArgsConstructor

public class User  implements Serializable {

  private String name;

  private String Date;

}

导入spring-context依赖

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>4.12</version>

      <scope>test</scope>

    </dependency>

    <dependency>

      <groupId>redis.clients</groupId>

      <artifactId>jedis</artifactId>

      <version>2.9.0</version>

    </dependency>

    <dependency>

      <groupId>org.projectlombok</groupId>

      <artifactId>lombok</artifactId>

      <version>1.18.12</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-context</artifactId>

      <version>5.2.6.RELEASE</version>

    </dependency>

创建Demo测试类,编写内容

  @Test

  public void Test2() {

//    连接Redis

    Jedis jedis = new Jedis("localhost", 6379);

//    准备key(String) -value (user)

    String key = "user";

    User value = new User("张三", "1999");

//    将key和value转换为byte[]

    byte[] byteKey = SerializationUtils.serialize(key);

    byte[] byteValue = SerializationUtils.serialize(value);

//    将key和value存储到Redis

    jedis.set(byteKey, byteValue);

//    释放资源

    jedis.close();

Jedis如何从Redis读取一个对象

测试

@Test

  public void Test3() {

//    连接Redis

    Jedis jedis = new Jedis("localhost", 6379);

//    准备一个key

    String key = "user";

//    将key转换为字节数组类型

    byte[] byteKey = SerializationUtils.serialize(key);

//    jedis去redis中获取value

    byte[] value = jedis.get(byteKey);

//    将value反序列化

    User user = (User) SerializationUtils.deserialize(value);

    System.out.println(user);

//    释放资源

    jedis.close();

  }

如何将一个对象以字符串的形式存储到Redis

导入依赖

 <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>4.12</version>

      <scope>test</scope>

    </dependency>

    <dependency>

      <groupId>redis.clients</groupId>

      <artifactId>jedis</artifactId>

      <version>2.9.0</version>

    </dependency>

    <dependency>

      <groupId>org.projectlombok</groupId>

      <artifactId>lombok</artifactId>

      <version>1.18.12</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-context</artifactId>

      <version>5.2.6.RELEASE</version>

    </dependency>

    <dependency>

      <groupId>com.alibaba</groupId>

      <artifactId>fastjson</artifactId>

      <version>1.2.70</version>

    </dependency>

    <dependency>

      <groupId>org.junit.jupiter</groupId>

      <artifactId>junit-jupiter</artifactId>

      <version>RELEASE</version>

      <scope>compile</scope>

    </dependency>

测试

  @Test

  public void test1(){

//    连接Redis

    Jedis jedis = new Jedis("localhost",6379);

//    准备key(String) - value(User)

    String key = "stringUser";

    User value = new User("帅哥","19999");

//    使用fastJSON将value转换为json字符串

    String stringValue = JSON.toJSONString(value);

//    存储到Redis中

    jedis.set(key,stringValue);

//    释放资源

    jedis.close();

  }

如何得到Redis中以字符串(JSON)存在形式的对象

依赖同上

测试

 @Test

  public void test2(){

//    连接Redis

    Jedis jedis = new Jedis("localhost",6379);

//准备一个key

    String key = "stringUser";

    //去Redis中查询value

    String value = jedis.get(key);

    //将value反序列化一个对象

    User user = JSON.parseObject(value, User.class);

    System.out.println("user = "+ user);

//    释放资源

    jedis.close();

  }