SpringBoot整合SpringData Jpa 与Redis

1.导入起步依赖

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.1.RELEASE
         
    


    com.itheima
    mySpringBoot_SpringDataJpa
    1.0-SNAPSHOT

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
        
            org.springframework.boot
            spring-boot-starter-data-jpa
        

        
        
            mysql
            mysql-connector-java
        

       
        
        
            org.springframework.boot
            spring-boot-starter-data-redis
        


    

    

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

#DB Configuration:
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/jpa?useUnicode=true&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=root

#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

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

 

3.创建实体配置实体

package com.itheima.domain;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User{

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String password;
    private String name;

    public Long getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

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

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

 5.编写dao层接口

package com.itheima.dao;

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

import java.util.List;

public interface UserDao extends JpaRepository,JpaSpecificationExecutor {

}

package com.itheima.test;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.itheima.SpringbootJpaApplication;
import com.itheima.dao.UserDao;
import com.itheima.domain.User;
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 = SpringbootJpaApplication.class )
public class TestJpa {

     @Autowired
     private UserDao userDao;
      @Autowired
     private RedisTemplateredisTemplate;
    @Test
    public void testJpa(){

        List all = userDao.findAll();
        System.out.println(all);
    }
    @Test
    public void testRedis() throws JsonProcessingException {

        //先从缓存查
        String all = redisTemplate.boundValueOps("All").get();
        if(all==null){

            List userAll = userDao.findAll();

            System.out.println("从数据库查询");
            //转换成json格式字符串
            ObjectMapper om = new ObjectMapper();
            String value = om.writeValueAsString(userAll);
            redisTemplate.boundValueOps("All").set(value);

        }else {


            System.out.println("从缓存中查询");
        }
        System.out.println(all);

    }
}