系统2

package com.example.accessingdatajpa;

import jakarta.persistence.Entity;

import jakarta.persistence.GeneratedValue;

import jakarta.persistence.GenerationType;

import jakarta.persistence.Id;

@Entity

public class Customer {

@Id @GeneratedValue(strategy=GenerationType.AUTO

)

private Long id;

private String firstName; private String lastName;

protected Customer() {} public Customer(String firstName, String lastName)

{ this.firstName = firstName; this.lastName = lastName; }

@Override

public String toString() {

return String.format( "Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);

} public Long getId() { return id; }

public String getFirstName() {

return firstName; } public String getLastName() { return lastName;

} }