@Embedded 和 @Embeddable

[@Embedded 和 @Embeddable]
指定其值为可嵌入类实例的实体的持久字段或属性。
    可嵌入类必须标注为Embeddable。
 @Embedded 用来修饰 对象属性(引用类型 -- 类对象 -- 属性注解)
 @Embeddable 用来修饰 类(类注解)
 用来复用类对象的属性 可使用 @AttributeOverrides 来进行重写
  如 AttributeOverride，AttributeOverrides， 
  AssociationOverride，和AssociationOverrides 
  注释可以用于覆盖声明或嵌入类默认映射。 
    
/**
 * @AttributeOverrides
 *  用于重新定义列名
 *   @AttributeOverride
 *      name == 代表类的属性名
 *      column 代表 @Column 并重写相应的参数即可
*/
@Embedded
@AttributeOverrides({
        @AttributeOverride(name="view1",column = 
                            @Column(name="view_1")),
        @AttributeOverride(name="view2",column =
                            @Column(name="view_2",length = 100))
})
private ViewProperty viewProperty; 
      其中view1 和 view2 是 ViewProperty的属性

package sun.rain.amazing.javax.anno.domain.embedded;

import lombok.Data;

import javax.persistence.Embeddable;
import java.io.Serializable;

/**
 * @author  sunRainAmazing
 */
@Data
@Embeddable
public class ViewProperty implements Serializable {
    private String view1;
    private String view2;
}

package sun.rain.amazing.javax.anno.domain.embedded;

import lombok.Data;

import javax.persistence.Embeddable;
import java.io.Serializable;

/**
 * @author  sunRainAmazing
 */
@Data
@Embeddable
public class DtoProperty  implements Serializable {
    private String desc1;
    private String desc2;
    private ViewProperty viewProperty;
}

package sun.rain.amazing.javax.anno.domain.embedded;

import lombok.Data;
import sun.rain.amazing.core.eums.ErrorPropertyMustCancel;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

/**
 * @author Reese
 */
@Data
@Entity
public class UserEmbedded {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    private String name;

    // Persistent component using defaults
    private DtoProperty dtoProperty;
    /**
     * 报错 Repeated column in mapping for entity:
     *   sun.rain.amazing.javax.anno.domain.embedded.UserEmbedded column
     * 因此将其注销
  *
     */
//    @ErrorPropertyMustCancel
//    private ViewProperty viewProperty;

}

/*

CREATE TABLE `user_embedded` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `desc1` varchar(255) DEFAULT NULL,
  `desc2` varchar(255) DEFAULT NULL,
  `view1` varchar(255) DEFAULT NULL,
  `view2` varchar(255) DEFAULT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8


 */