一、Lettuce
Redis这里就不多说,服务端的启动之前的博客里面也有提到,这里略过。Lettuce和Jedis都是连接Redis Server的客户端程序,Jedis在实现上是直连redis server,多线程环境下非线程安全,除非使用连接池,为每个Jedis实例线程间并发访问,且线程安全,满足多线程环境下的并发访问,同时它是可伸缩的设计,一个连接实例不够的情况也可以按需增加连接实例。
二、maven依赖
还是按照原来的步骤,先是导入依赖,然后配置属性,最后实例,其实使用springboot都是差不多的步骤。
<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>
三、属性配置
这里使用的是lettuce,如果使用Jedis,把下面的lettuce改成Jedis就好。
spring.redis.host=127.0.0.1
spring.redis.password=
spring.redis.port= 6379
spring.redis.timeout=1000
spring.redis.database=0
spring.redis.lettuce.pool.min-idle=0
spring.redis.lettuce.pool.max-idle=8
spring.redis.lettuce.pool.max-wait=-1ms
spring.redis.lettuce.pool.max-active=8
四、实例
这里还是在之前demo的基础上进行修改.默认情况下的模板只能支持StringRedisTemplate<String,String>,只能存字符串。这时需要自定义模板,当自定义模板后又想存储String字符串时,可以使用RedisTemplate的方式,他们俩并不冲突。在RedisCacheAutoConfiguration中自定义了一个RedisTemplate。
package com.example.config;
import java.io.Serializable;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@Configuration
@AutoConfigureAfter(RedisAutoConfiguration.class)
public class RedisCacheAutoConfiguration {
@Bean
public RedisTemplate<String, Serializable> redisCacheTemplate(LettuceConnectionFactory redisConnectionFactory) {
RedisTemplate<String, Serializable> template = new RedisTemplate<>();
template.setKeySerializer(new StringRedisSerializer());
template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
template.setConnectionFactory(redisConnectionFactory);
return template;
}
}
在User类中增加了构造函数。
package com.example.model;
import java.io.Serializable;
public class User implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
@Override
public String toString() {
// TODO Auto-generated method stub
return "User [id=" + Id + ", name=" + Name + ", age=" + Age + "]";
}
public User(String id, String name, int age, UserSexEnum sex) {
super();
Id = id;
Name = name;
Age = age;
Sex = sex;
}
public User() {
super();
// TODO Auto-generated constructor stub
}
public String getId() {
return Id;
}
public void setId(String id) {
Id = id;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public int getAge() {
return Age;
}
public void setAge(int age) {
Age = age;
}
private String Id;
private String Name;
private int Age;
private UserSexEnum Sex;
public UserSexEnum getSex() {
return Sex;
}
public void setSex(UserSexEnum sex) {
Sex = sex;
}
}
View Code
修改之前demo中的UserController,在里面注入StringRedisTemplate和RedisTemplate用来测试。增加的主要代码是39-46行处。
package com.example.demo;
import java.io.Serializable;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.example.model.User;
import com.example.model.UserSexEnum;
import com.example.read.mapper.ReadUserMapper;
import com.example.write.mapper.WriteUserMapper;
@Controller
@RequestMapping("/user")
public class UserController {
@Autowired
private WriteUserMapper userMapperWrite;
@Autowired
private ReadUserMapper userMapperRead;
@Autowired
private StringRedisTemplate stringRedisTemplate;
@Autowired
private RedisTemplate<String, Serializable> redisCacheTemplate;
@RequestMapping(value = "/alluser.do",method = RequestMethod.GET)
public String getallusers(Model model) {
List<User> users=userMapperRead.getAll();
model.addAttribute("users", users);
stringRedisTemplate.opsForValue().set("keytest", "cuiyw");
final String keytest = stringRedisTemplate.opsForValue().get("keytest");
model.addAttribute("keytest", keytest);
String key = "1857XXXX040";
redisCacheTemplate.opsForValue().set(key, new User(key, "cuiyw", 18, UserSexEnum.MAN));
// TODO 对应 String(字符串)
final User user = (User) redisCacheTemplate.opsForValue().get(key);
model.addAttribute("user", user);
return "userlist";
}
@RequestMapping(value = "/insert.do",method = RequestMethod.GET)
public String adduser(Model model) {
User user=new User();
user.setName("cuiyw");
user.setAge(27);
userMapperWrite.insert(user);
List<User> users=userMapperWrite.getAll();
model.addAttribute("users", users);
return "userlist";
}
}
View Code
打开url:http://localhost:8080/user/alluser.do,可以看到从redis获取的String类型的key和User对象。
五、错误
这里在打开url时报了一个redis连接超时的错误io.lettuce.core.RedisCommandTimeoutException: Command timed out,我开始以为是设置的timeout太小导致的,可我设置到10000时还是报错,后来又回顾了下之前redis server启动的方法,启动时增加redis.windows.conf,使用redis-server.exe redis.windows.conf启动后居然可以了,可能是我之前双击启动有问题导致的。
这里只是实现Redis的简单使用,在实际项目中还要有集群以及结合cache来一起使用的场景,后续再慢慢补充。