SpringBoot 增删改查

public interface CrudRepository<T,ID> extends Repository<T,ID>

public interface StudentRepository extends CrudRepository<Student, Integer>
{
}

public interface BookDAO extends JpaRepository 
{
}

package com.nhooo.model;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
//mark class as an Entity 
@Entity
//defining class name as Table name
@Table
public class Books
{
//Defining book id as primary key
@Id
@Column
private int bookid;
@Column
private String bookname;
@Column
private String author;
@Column
private int price;
public int getBookid() 
{
return bookid;
}
public void setBookid(int bookid) 
{
this.bookid = bookid;
}
public String getBookname()
{
return bookname;
}
public void setBookname(String bookname) 
{
this.bookname = bookname;
}
public String getAuthor() 
{
return author;
}
public void setAuthor(String author) 
{
this.author = author;
}
public int getPrice() 
{
return price;
}
public void setPrice(int price) 
{
this.price = price;
}
}

package com.nhooo.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import com.nhooo.model.Books;
import com.nhooo.service.BooksService;
//将类标记为 Controller
@RestController
public class BooksController 
{
    //自动装配BooksService类
    @Autowired
    BooksService booksService;
    //创建从数据库检索所有图书详细信息的get映射
    @GetMapping("/book")
    private List<Books> getAllBooks() 
    {
    return booksService.getAllBooks();
    }
    //创建检索特定书籍详细信息的get映射
    @GetMapping("/book/{bookid}")
    private Books getBooks(@PathVariable("bookid") int bookid) 
    {
    return booksService.getBooksById(bookid);
    }
    //创建删除映射，删除指定的书
    @DeleteMapping("/book/{bookid}")
    private void deleteBook(@PathVariable("bookid") int bookid) 
    {
    booksService.delete(bookid);
    }
    //创建在数据库中发布书籍详细信息的post映射
    @PostMapping("/books")
    private int saveBook(@RequestBody Books books) 
    {
    booksService.saveOrUpdate(books);
    return books.getBookid();
    }
    //创建更新图书详细信息的put映射
    @PutMapping("/books")
    private Books update(@RequestBody Books books) 
    {
    booksService.saveOrUpdate(books);
    return books;
    }
}

package com.nhooo.service;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.nhooo.model.Books;
import com.nhooo.repository.BooksRepository;
//定义业务逻辑
@Service
public class BooksService 
{
    @Autowired
    BooksRepository booksRepository;
    //使用 cruddrepository 的 findaAll ()方法获取所有书籍记录
    public List<Books> getAllBooks() 
    {
    List<Books> books = new ArrayList<Books>();
    booksRepository.findAll().forEach(books1 -> books.add(books1));
    return books;
    }
    //通过使用 cruddrepository 的 findById ()方法获取特定的记录
    public Books getBooksById(int id) 
    {
    return booksRepository.findById(id).get();
    }
    //使用CrudRepository的save()方法保存特定记录
    public void saveOrUpdate(Books books) 
    {
    booksRepository.save(books);
    }
    //使用CrudRepository的deleteById()方法删除特定记录
    public void delete(int id) 
    {
    booksRepository.deleteById(id);
    }
    //更新记录
    public void update(Books books, int bookid) 
    {
    booksRepository.save(books);
    }
}

package com.nhooo.repository;
import org.springframework.data.repository.CrudRepository;
import com.nhooo.model.Books;
//repository that extends CrudRepository
public interface BooksRepository extends CrudRepository<Books, Integer>
{
}

spring.datasource.url=jdbc:h2:mem:books_data
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect#enabling the H2 consolespring.h2.console.enabled=true

package com.nhooo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringBootCrudOperationApplication 
{
public static void main(String[] args) 
{
SpringApplication.run(SpringBootCrudOperationApplication.class, args);
}
}

{
    "bookid": "5433",
    "bookname": "Core and Advance Java",
    "author": "R. Nageswara Rao",
    "price": "800"
}

{"bookid": "0982","bookname": "Programming with Java","author": "E. Balagurusamy","price": "350"
} 
{
    "bookid": "6321",
    "bookname": "Data Structures and Algorithms in Java",
    "author": "Robert Lafore",
    "price": "590"
} 
{
    "bookid": "5433",
    "bookname": "Effective Java",
    "author": "Joshua Bloch",
    "price": "670"
}

{
    "bookid": "6321",
    "bookname": "Data Structures and Algorithms in Java",
    "author": "Robert Lafore",
    "price": "500"
}