SpringBoot学习笔记（五）—— SpringBoot整合SpringDataJPA、Redis

SpringBoot整合Spring Data JPA

• 添加Spring Data JPA的起步依赖

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

• 添加数据库驱动依赖

    mysql
    mysql-connector-java

• 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/test?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

---

• 创建实体配置实体

package com.demo.pojo;

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

@Entity
public class User {
    // 主键

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    // 用户名
    private String username;
    // 密码
    private String password;
    // 姓名
    private String name;

    @Id
    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 + '\'' +
                '}';
    }
}

• 编写UserRepository

package com.demo.mapper;

import com.demo.pojo.User;
import org.springframework.data.jpa.repository.JpaRepository;
import java.util.List;

public interface UserRepository extends JpaRepository{
    public List findAll();
}

• 编写测试类

package com.demo;

import com.demo.mapper.UserRepository;
import com.demo.pojo.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.test.context.junit4.SpringRunner;

import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest(classes=Demo1Application.class)
public class JpaTest {

    @Autowired
    private UserRepository userRepository;

    @Test
    public void test(){
        List users = userRepository.findAll();
        System.out.println(users);
    }

}

• 控制台打印信息

SpringBoot整合Redis

• 添加redis的起步依赖

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

• application.properties中配置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

package com.demo;

import com.demo.mapper.UserRepository;
import com.demo.pojo.User;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
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 = Demo1Application.class)
public class RedisTest {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private RedisTemplate redisTemplate;

    @Test
    public void test() throws JsonProcessingException {
        //从redis缓存中获得指定的数据
        String userListData = redisTemplate.boundValueOps("user.findAll").get();
        //如果redis中没有数据的话
        if(null==userListData){
            //查询数据库获得数据
            List all = userRepository.findAll();
            //转换成json格式字符串
            ObjectMapper om = new ObjectMapper();
            userListData = om.writeValueAsString(all);
            //将数据存储到redis中，下次在查询直接从redis中获得数据，不用再查询数据库
            redisTemplate.boundValueOps("user.findAll").set(userListData);
            System.out.println("===============从数据库获得数据===============");
        }else{
            System.out.println("===============从redis缓存中获得数据===============");
        }

        System.out.println(userListData);

    }

}