maven 构建spring boot + mysql 的基础项目

Posted 2020-09-04 oftenlin

一、maven 依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

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

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

    </dependencies>

二、配置文件 application.properties

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/sbtest
spring.datasource.username=root
spring.datasource.password=1234
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming.strategy=org.hibernate.cfg.ImprovedNamingStrategy

三、建立Entity和Repository

1、Book 实体类

package com.casic.entity;

import javax.persistence.*;
import java.util.List;

@Entity
public class Book {
    @Id
    @GeneratedValue
    private Long id;
    private String isbn;
    private String title;
    private String description;

    @ManyToOne
    private Author author;
    @ManyToOne
    private Publisher publisher;

    @ManyToMany
    private List<Reviewer> reviewers;

    protected Book() { }

    public Book(Author author, String isbn, Publisher publisher, String title) {
        this.author = author;
        this.isbn = isbn;
        this.publisher = publisher;
        this.title = title;
    }
}

2、Author 实体类

package com.casic.entity;

import javax.persistence.*;
import java.util.List;

@Entity
public class Author {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;
    @OneToMany(mappedBy = "author")
    private List<Book> books;

    protected Author() {

    }

    public Author(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

3、Publisher 实体类

package com.casic.entity;

import javax.persistence.*;
import java.util.List;

@Entity
public class Publisher {
    @Id
    @GeneratedValue
    private Long id;
    private String name;

    @OneToMany(mappedBy = "publisher")
    private List<Book> books;

    protected Publisher() { }

    public Publisher(String name) {
        this.name = name;
    }

}

4、Reviewer

package com.casic.entity;
import javax.persistence.*;
@Entity
public class Reviewer {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;

    protected Reviewer() { }

    public Reviewer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

5、BookRepository 

package com.casic.repository;


import com.casic.entity.Book;
        import org.springframework.data.repository.CrudRepository;
        import org.springframework.stereotype.Repository;

@Repository
public interface BookRepository extends CrudRepository<Book, Long> {
    Book findBookByIsbn(String isbn);
}

6、MyStartupRunner 命令行启动类

package com.casic.service;

import com.casic.repository.BookRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;

/**
 * 服务启动执行
 * @author   oftenlin
 */
@Component
public class MyStartupRunner implements CommandLineRunner {

    @Autowired
    private BookRepository bookRepository;
    @Override
    public void run(String... args) throws Exception {
        System.out.print("book count:"+bookRepository.count());
    }

}

7、启动类 MyApp 

package com.casic;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;

@SpringBootApplication
public class MyApp{

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