SpringBoot整合Spring Data JPA和redis

添加Spring Data JPA的起步依赖

<!-- 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>

添加Junit的起步依赖

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

添加数据库驱动依赖

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

在application.properties中配置数据库和jpa的相关属性

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

创建实体配置实体

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 +
                '}';
    }
}

编写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();

}

编写测试类

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整合Redis

添加redis的起步依赖

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

配置redis的连接信息

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

注入RedisTemplate测试redis操作
首先从redis中查询所需数据，如果没有则去数据库查询，并将查询到的数据存入redis，方便下次查询

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);
    }
}