springboot系列05：redis使用

Redis 介绍

redis 是目前使用最为广泛的内存数据存储，支持丰富的数据结构，如hashes, lists, sets 等，同时支持数据持久化。除此之外，Redis 还提供一些类数据库的特性，比如事务，HA，主从库。

Redis 在springboot中的使用

引入依赖包

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
</dependency> 
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

添加配置文件

# Redis数据库索引（默认为0）
spring.redis.database=0 
# Redis服务器地址
spring.redis.host=localhost
# Redis服务器连接端口
spring.redis.port=6379 
# Redis服务器连接密码（默认为空）
spring.redis.password=
# 连接池最大连接数（使用负值表示没有限制） 默认 8
spring.redis.lettuce.pool.max-active=8
# 连接池最大阻塞等待时间（使用负值表示没有限制） 默认 -1
spring.redis.lettuce.pool.max-wait=-1
# 连接池中的最大空闲连接 默认 8
spring.redis.lettuce.pool.max-idle=8
# 连接池中的最小空闲连接 默认 0
spring.redis.lettuce.pool.min-idle=0

添加cache配置类

package com.example.redis.config;
 
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
import java.lang.reflect.Method;
 
@Configuration
@EnableCaching  //开启缓存
public class RedisConfig extends CachingConfigurerSupport {
 
    @Bean
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }
}

测试类

package com.example.redis.test;
 
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
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.StringRedisTemplate;
import org.springframework.test.context.junit4.SpringRunner;
 
@RunWith(SpringRunner.class)
@SpringBootTest
public class TestRedis {
 
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private RedisTemplate redisTemplate;
 
    @Test
    public void testRedisSet() throws Exception {
        stringRedisTemplate.opsForValue().set("aaa", "111");
        Assert.assertEquals("111", stringRedisTemplate.opsForValue().get("aaa"));
    } 
 
}

启动redis，运行TestRedis.testRedisSet 测试类报错信息：

java.lang.IllegalStateException: Unable to find a @SpringBootConfiguration, you need to use @ContextConfiguration or @SpringBootTest(classes=...) with your test
 
  at org.springframework.util.Assert.state(Assert.java:73)
  at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.getOrFindConfigurationClasses(SpringBootTestContextBootstrapper.java:233)

package com.example.redis.test;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 
@SpringBootApplication
public class RedisApplicationTest {
 
    public static void main(String[] args) {
        SpringApplication.run(RedisApplicationTest.class,args);
    }
}

成功结果:

redis操作对象User

package com.example.domain;
 
import lombok.Data;
 
import java.io.Serializable;
import java.util.Date;
 
@Data
public class User implements Serializable {
        private static final long serialVersionUID = 1L;
 
        private Long id;
        private String userName;
        private String password;
        private String email;
        private String nickname;
        private Date regTime;

测试对象是否存在

@Test
    public void testUserExist() throws Exception {
        User user=new User(1L,"zhangl", "123456", "1796969389@qq.com", "zhangl",new Date());
        redisTemplate.opsForValue().set("User::"+ user.getId(), user);
        Assert.assertEquals(true, redisTemplate.hasKey("User::"+ user.getId()));
    }

测试获取对象属性

@Test
 public void testUserName() throws Exception {
     User user=new User(1L,"zhangl", "123456", "1796969389@qq.com", "zhangl",new Date());
     redisTemplate.opsForValue().set("User::"+ user.getId(), user);
     Assert.assertEquals("zhangl", ((User)redisTemplate.opsForValue().get("User::"+ user.getId())).getUserName());
 }

```
测试删除对象
```

@Test
 public void testUserDelete() throws Exception {
     User user=new User(1L,"zhangl", "123456", "1796969389@qq.com", "zhangl",new Date());
     redisTemplate.opsForValue().set("User::"+ user.getId(), user);
     redisTemplate.delete("User::"+ user.getId());
     Assert.assertEquals(false, redisTemplate.hasKey("User::"+ user.getId()));
 }

```
测试过期时间
```

@Test
public void testUserSetTime() throws Exception {
    User user=new User(1L,"zhangl", "123456", "1796969389@qq.com", "zhangl",new Date());
    redisTemplate.opsForValue().set("User::"+ user.getId(), user,1, TimeUnit.SECONDS);
    Assert.assertEquals(true, redisTemplate.hasKey("User::"+ user.getId()));
    //等待1s
    Thread.sleep(1000L);
    Assert.assertEquals(false, redisTemplate.hasKey("User::"+ user.getId())); 
}