package com.ada.data.entity;import java.io.Serializable;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.MappedSuperclass;@MappedSuperclasspublic class NumEntity
    
      implements Serializable {	@Id	@GeneratedValue(strategy = GenerationType.AUTO)	private NUM id;	public NUM getId() {		return id;	}	public void setId(NUM id) {		this.id = id;	}	@Override	public int hashCode() {		final int prime = 31;		int result = 1;		result = prime * result + ((id == null) ? 0 : id.hashCode());		return result;	}	@Override	public boolean equals(Object obj) {		if (this == obj)			return true;		if (obj == null)			return false;		if (getClass() != obj.getClass())			return false;		NumEntity other = (NumEntity) obj;		if (id == null) {			if (other.id != null)				return false;		} else if (!id.equals(other.id))			return false;		return true;	}}
    

package com.tongna.rest.apps;import com.ada.data.entity.NumEntity;public class A extends NumEntity
    
      {}
    

A a = new A();		a.setId(1l);		Class
     ccc = a.getClass().getMethod("getId").getReturnType();		System.out.println(ccc);		System.out.println(a.getId().getClass());

java泛型不是计算运行时的数据类型。

所以在使用BeanUtils.copyProperties(source, result);的时候id不能拷贝。