SpringBoot開發日記(二)——連接數據庫

 在application.properties中添加:

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/hzktest?serverTimezone=UTC
spring.datasource.username=******
spring.datasource.password=******
spring.datasource.max-idle=10
spring.datasource.max-wait=10000
spring.datasource.min-idle=5
spring.datasource.initial-size=5

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

寫Controller層

@RestController
public class UserController {

    @Autowired
    private UserRepository userRepo;

    @GetMapping(value = "/user")
    public List<User> userList(){
        return userRepo.findAll();
    }

}

寫Dao層

..
import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository<User,Integer> {
}

這裏要說一下pom.xml需要引入maven庫纔可以繼承JpaRepository：

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

寫entity：

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

@Entity
public class User {

    @Id
    @GeneratedValue
    private Integer id;
    private String age;
    private String name;

    public Integer getId() {
        return id;
    }

    public User() {
    }

    public User(Integer id, String age, String name) {
        this.id=id;
        this.age = age;
        this.name = name;
    }

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

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

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

最終的目錄結構爲：