更新
根据反馈和 John 的 answer，我更新了答案，不再使用 @Tolerate 或 @Data，而是通过 @Getter 和 @Setter 创建访问器和修改器，创建默认值构造函数通过@NoArgsConstructor，最后我们通过@AllArgsConstructor创建构建器需要的全参数构造函数。
由于您想使用构建器模式，我想您想限制构造函数和修改器方法的可见性。
为了实现这一点，我们通过@NoArgsConstructor 和@AllArgsConstructor 注释上的access 属性以及value 注释上的value 属性将可见性设置为package private。
重要
请记住正确覆盖toString、equals 和hashCode。
有关详细信息，请参阅 Vlad Mihalcea 的以下帖子：
package com.stackoverflow.SO34299054;
import static org.junit.Assert.*;
import java.util.Random;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import org.junit.Test;
import lombok.AccessLevel;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
@SuppressWarnings("javadoc")
public class Answer {
@Entity
@Builder(toBuilder = true)
@AllArgsConstructor(access = AccessLevel.PACKAGE)
@NoArgsConstructor(access = AccessLevel.PACKAGE)
@Setter(value = AccessLevel.PACKAGE)
@Getter
public static class Person {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
/*
* IMPORTANT:
* Set toString, equals, and hashCode as described in these
* documents:
* - https://vladmihalcea.com/the-best-way-to-implement-equals-hashcode-and-tostring-with-jpa-and-hibernate/
* - https://vladmihalcea.com/how-to-implement-equals-and-hashcode-using-the-jpa-entity-identifier/
* - https://vladmihalcea.com/hibernate-facts-equals-and-hashcode/
*/
}
/**
* Test person builder.
*/
@Test
public void testPersonBuilder() {
final Long expectedId = new Random().nextLong();
final Person fromBuilder = Person.builder()
.id(expectedId)
.build();
assertEquals(expectedId, fromBuilder.getId());
}
/**
* Test person constructor.
*/
@Test
public void testPersonConstructor() {
final Long expectedId = new Random().nextLong();
final Person fromNoArgConstructor = new Person();
fromNoArgConstructor.setId(expectedId);
assertEquals(expectedId, fromNoArgConstructor.getId());
}
}
使用@Tolerate 和@Data 的旧版本：
使用 @Tolerate 允许添加 noarg 构造函数。
由于您想使用构建器模式，我想您想控制 setter 方法的可见性。
@Data 注释使生成的 setter 成为public，将@Setter(value = AccessLevel.PROTECTED) 应用于字段使它们成为protected。
请记住正确覆盖toString、equals 和hashCode。
有关详细信息，请参阅 Vlad Mihalcea 的以下帖子：
package lombok.javac.handlers.stackoverflow;
import static org.junit.Assert.*;
import java.util.Random;
import javax.persistence.GenerationType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import lombok.AccessLevel;
import lombok.Builder;
import lombok.Data;
import lombok.Setter;
import lombok.experimental.Tolerate;
import org.junit.Test;
public class So34241718 {
@Builder
@Data
public static class Person {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Setter(value = AccessLevel.PROTECTED)
Long id;
@Tolerate
Person() {}
/* IMPORTANT:
Override toString, equals, and hashCode as described in these
documents:
- https://vladmihalcea.com/the-best-way-to-implement-equals-hashcode-and-tostring-with-jpa-and-hibernate/
- https://vladmihalcea.com/how-to-implement-equals-and-hashcode-using-the-jpa-entity-identifier/
- https://vladmihalcea.com/hibernate-facts-equals-and-hashcode/
*/
}
@Test
public void testPersonBuilder() {
Long expectedId = new Random().nextLong();
final Person fromBuilder = Person.builder()
.id(expectedId)
.build();
assertEquals(expectedId, fromBuilder.getId());
}
@Test
public void testPersonConstructor() {
Long expectedId = new Random().nextLong();
final Person fromNoArgConstructor = new Person();
fromNoArgConstructor .setId(expectedId);
assertEquals(expectedId, fromNoArgConstructor.getId());
}
}