书模型

package com.mcf7.spring.domain;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.io.Serializable;

@lombok.Getter
@lombok.Setter
@lombok.EqualsAndHashCode(of = "isbn")
@lombok.ToString(exclude="id")
@Entity
public class Book implements Serializable {

    public Book() {}

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private long id;

    @NotNull
    @Size(min = 1)
    private String isbn;

    @NotNull
    @Size(min = 1)
    private String title;

    @NotNull
    @Size(min = 1)
    private String author;

    @NotNull
    @Size(min = 1)
    private String description;
}

只是注意，因为这里发生了一些事情，我想快速分解它们。

@lombok 的所有注释都会产生一些我们类的锅炉板

@lombok.Getter  //Creates getter methods for our variables

@lombok.Setter  //Creates setter methods four our variables

@lombok.EqualsAndHashCode(of = "isbn") //Creates Equals and Hashcode methods based off of the isbn variable

@lombok.ToString(exclude="id") //Creates a toString method based off of every variable except id

我们还在此对象中使用了验证

@NotNull  //This specifies that when validation is called this element shouldn't be null

@Size(min = 1)  //This specifies that when validation is called this String shouldn't be smaller than 1