BeanUtils.copyProperties()拷贝id属性失败的原因及解决

public abstract class AbstractEntity<ID extends Serializable> implements Serializable { 
    protected ID id;
    
    protected ID createdBy;
    
    protected Date createdTime;
 
    
    protected ID lastModifiedBy;
    
    protected Date lastModifiedTime; 
    public void setId(ID id) {
        this.id = id;
    }
 
    public ID getId() {
        return this.id;
    }

if (readMethod != null && ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], readMethod.getReturnType())) 

BeanUtils.copyProperties(A,B);

BeanUtils.copyProperties(A,B);