SpringBoot學習之SpringBoot整合JPA

建立實體類Book

package org.hx.springboot_jpa_demo30.model;

import javax.persistence.*;

@Entity(name = "t_book")
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    @Column(name = "b_name")
    private String name;
    private String author;

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", author='" + author + '\'' +
                '}';
    }

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }
}

           

建立接口類BookDao

package org.hx.springboot_jpa_demo30.dao;

import org.hx.springboot_jpa_demo30.model.Book;
import org.springframework.data.jpa.repository.JpaRepository;

public interface BookDao extends JpaRepository<Book,Integer> {

}

           

配置application.properties

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.database-platform=mysql
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL55Dialect
           

在測試類中進行測試

package org.hx.springboot_jpa_demo30;

import org.hx.springboot_jpa_demo30.dao.BookDao;
import org.hx.springboot_jpa_demo30.model.Book;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;

import java.util.List;
import java.util.Optional;

@SpringBootTest
class SpringbootJpaDemo30ApplicationTests {

    @Autowired
    BookDao bookDao;
    @Test
    void contextLoads() {
        Book book = new Book();
        book.setName("紅樓夢");
        book.setAuthor("曹雪芹");
        bookDao.save(book);
    }
    @Test
    void test(){
        List<Book> bookList = bookDao.findAll();
        System.out.println(bookList);
        Optional<Book> byId = bookDao.findById(2);
        System.out.println("byId: "+byId);
        bookDao.deleteById(1);

    }
    @Test
    void test2(){
        //頁碼從0開始記，1表示第2頁
        PageRequest pageRequest = PageRequest.of(1, 3, Sort.by(Sort.Order.desc("id")));
        Page<Book> page= bookDao.findAll(pageRequest);
        System.out.println("總記錄數："+page.getTotalElements());
        System.out.println("總頁數："+page.getTotalPages());
        System.out.println("查到的資料："+page.getContent());
        System.out.println("每頁的記錄數："+page.getSize());
        System.out.println("是否還有下一頁："+page.hasNext());
        System.out.println("是否還有上一頁："+page.hasPrevious());
        System.out.println("是否是最後一頁："+page.isLast());
        System.out.println("是否是第一頁："+page.isFirst());
        System.out.println("目前頁數："+page.getNumber());
        System.out.println("目前面記錄數："+page.getNumberOfElements());
    }

}