springboot与h2database实践

原文链接： https://github.com/longfeizheng

一、h2database是一个开源的嵌入式数据库引擎，采用java语言编写，不受平台的限制，同时H2提供了一个十分方便的web控制台用于操作和管理数据库内容。H2还提供兼容模式，可以兼容一些主流的数据库，因此采用H2作为开发期的数据库非常方便。
二、h2database与springboot结合、首先是目录结构如下：

三、pom.xml文件

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.9.RELEASE
         
    
    com.citydo
    h2database
    0.0.1-SNAPSHOT
    h2database
    Demo project for Spring Boot

    
        1.8
    

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

        
            com.h2database
            h2
            runtime
        
        
            org.projectlombok
            lombok
            true
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

四、配置文件与sql脚本

spring:
  datasource:
    url: jdbc:h2:mem:h2test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
    platform: h2
    username: sa
    password:
    driverClassName: org.h2.Driver
  jpa:
    database-platform: org.hibernate.dialect.H2Dialect
    hibernate:
      ddl-auto: update
    properties:
      hibernate:
        show_sql: true
        use_sql_comments: true
        format_sql: true
  h2:
    console:
      enabled: true
      path: /console
      settings:
        trace: false
        web-allow-others: false
logging:
  level:
    root: INFO

data.sql

insert into user(id,username, name, age, balance) values(1,'user1', '张三', 20, 100.00);
insert into user(id,username, name, age, balance) values(2,'user2', '李四', 20, 100.00);
insert into user(id,username, name, age, balance) values(3,'user3', '王五', 20, 100.00);
insert into user(id,username, name, age, balance) values(4,'user4', '马六', 20, 100.00);

schema.sql

drop table user if exists;
create table user(
	id bigint generated by default as identity,
	username varchar(40),
	name varchar(20),
	age int(3),
	balance decimal(10,2),
	primary key(id)
);

五、代码片段
H2databaseController.java

package com.citydo.h2database.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class H2databaseController {

    @GetMapping("/")
    public String test() {
        return "你好";
    }
}

User.java

package com.citydo.h2database.domain;

import lombok.Data;

import javax.persistence.*;


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

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String username;

    private String name;

    private Integer age;

    private Double balance;

}

UserRepository.java

package com.citydo.h2database.repository;

import com.citydo.h2database.domain.User;
import org.springframework.data.jpa.repository.JpaRepository;

/**
 * Created on 2018/3/23.
 *
 * @author zlf
 * @since 1.0
 */
public interface UserRepository extends JpaRepository{
}

Springboot启动类

package com.citydo.h2database;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class H2databaseApplication {

    public static void main(String[] args) {
        SpringApplication.run(H2databaseApplication.class, args);
    }

}

测试类

package com.citydo.h2database;

import com.citydo.h2database.domain.User;
import com.citydo.h2database.repository.UserRepository;
import lombok.extern.slf4j.Slf4j;
import org.junit.Assert;
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
@Slf4j
public class H2databaseApplicationTests {

    @Test
    public void contextLoads() {
    }

    @Autowired
    private UserRepository userRepository;

    @Test
    public void saveTest() throws Exception {
        User user = new User();
        user.setName("你好");
        user.setUsername("user5");
        user.setAge(10);
        user.setBalance(100.00d);
        User result = userRepository.save(user);
        System.out.println("---------"+result.getId());
        Assert.assertNotNull(user.getId());
    }

    @Test
    public void findOneTest() throws Exception{
        List all = userRepository.findAll();
        System.out.println("----------"+all.size());
        for (User user:all){
            System.out.println(user.getName());
        }
        User one = userRepository.getOne(1l);
        Assert.assertNotNull(one);
        Assert.assertTrue(1L==one.getId());
    }


}

验证h2数据库是否连接成功

注意：这是连接数据库界面同时要查看这3个红色标记的地方是否与springboot配置文件一致。