SpringBoot整合Spring Data JPA

墨蓝 2022-01-27 02:29 251阅读 0赞

## 5.3 SpringBoot整合Spring Data JPA ##

**5.3.1 添加Spring Data JPA的起步依赖**

<dependency>
    	<groupId>org.springframework.boot</groupId>
    	<artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

**5.3.2 添加数据库驱动依赖**

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

**5.3.3 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://你自己的ip:3306/数据库名称?
    useUnicode=true&characterEncoding=utf8
    spring.datasource.username=你的用户名
    spring.datasource.password=你的密码
    #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

**5.3.4 创建实体配置实体**

@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;
    
        public User(Long id, String username, String password, String name) {
            this.id = id;
            this.username = username;
            this.password = password;
            this.name = name;
        }
    
        public User() {
        }
    
        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 + '\'' +
                    '}';
        }
    }

**5.3.5 编写UserRepository**

public interface UserRepository extends JpaRepository<User,Long>{
    	public List<User> findAll();
    	}
    }

**5.3.6 编写测试类**

@RunWith(SpringRunner.class)
    @SpringBootTest(classes=MySpringBootApplication.class)
    public class JpaTest {
    	@Autowired
    	private UserRepository userRepository;
    	
    	@Test
    	public void test(){
    	List<User> users = userRepository.findAll();
    	System.out.println(users);
    	}
    }

**5.3.7 控制台打印信息**

Hibernate: select user0_.id as id1_0_, user0_.name as name2_0_, user0_.password as password3_0_, user0_.username as username4_0_ from user user0_
    [User{id=1, username='zhangsan', password='123', name='张三'}, User{id=2, username='lisi', password='123', name='李四'}]