SpringBoot integrates Spring Data JPA and redis

Add the initial dependency of Spring Data JPA

<!-- springBoot JPA的起步依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!--jdk9需要导入如下坐标-->
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.0</version>
</dependency>

Add the initial dependency of Junit

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

Add database driver dependency

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

Configure database and jpa related properties in application.properties

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql:///class_db?useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=qwe123

#JPA Configuration:
spring.jpa.database=MySQL
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.ImprovedNamingStrategy

Create entity configuration entity

import javax.persistence.*;

@Entity
@Table(name = "student")
public class User{
    
    

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String sex;
    private Integer age;

    public Long getId() {
    
    
        return id;
    }

    public void setId(Long id) {
    
    
        this.id = id;
    }

    public String getName() {
    
    
        return name;
    }

    public void setName(String name) {
    
    
        this.name = name;
    }

    public String getSex() {
    
    
        return sex;
    }

    public void setSex(String sex) {
    
    
        this.sex = sex;
    }

    public Integer getAge() {
    
    
        return age;
    }

    public void setAge(Integer age) {
    
    
        this.age = age;
    }

    @Override
    public String toString() {
    
    
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                '}';
    }
}

Write UserRepository

import com.sunyuqi.domain.User;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface UserRepository extends JpaRepository<User,Long>{
    
    

    public List<User> findAll();

}

Write test class

import com.sunyuqi.domain.User;
import com.sunyuqi.repository.UserRepository;
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.test.context.junit4.SpringRunner;

import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = DemoApplication.class)
public class JpaTest {
    
    

    @Autowired
    private UserRepository userRepository;

    @Test
    public void test(){
    
    
        List<User> users = userRepository.findAll();
        for (User user : users) {
    
    
            System.out.println(user);
        }
    }
}

SpringBoot integrates Redis

Add the starting dependency of redis

<!-- 配置使用redis启动器 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

Configure redis connection information

#Redis
spring.redis.host=127.0.0.1
spring.redis.port=6379

Inject RedisTemplate to test the redis operation.
First, query the required data from redis, if not, go to the database to query, and store the queried data in redis for the next query

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.sunyuqi.domain.User;
import com.sunyuqi.repository.UserRepository;
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.test.context.junit4.SpringRunner;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = DemoApplication.class)
public class RedisTest {
    
    

    @Autowired
    private RedisTemplate<String,String> redisTemplate;

    @Autowired
    private UserRepository userRepository;

    @Test
    public void test() throws JsonProcessingException {
    
    
        //从redis中获得数据 数据的形式json字符串
        String userListJson = redisTemplate.boundValueOps("user.findAll").get();
        //判断redis中是否存在数据
        if(null==userListJson){
    
    
            //不存在数据 从数据库查询
            List<User> all = userRepository.findAll();
            //将查询出的数据存储到redis缓存中
            //向将list集合转换成json格式的字符串  使用jackson进行转换
            ObjectMapper objectMapper = new ObjectMapper();
            userListJson = objectMapper.writeValueAsString(all);
            redisTemplate.boundValueOps("user.findAll").set(userListJson);
        }
        System.out.println(userListJson);
    }
}