如果你有俩个具有很多相同属性的JavaBean，而你又不想手动的用get()set()方法来COPY。这时候copyProperties()方法的作用就体现出来了。例如经常用到的和hibernate绑定的实体，和另一个实体属性值的copy
public class APDto {
private String ssid;
private String deviceMac;
private String bssid;
private String deviceNo;
private String deviceModel;
private String bandWidth;
private String bandOpr;
private String storeId;
private String storeName;
private String brandName;
private String storeProvince;
private String storeCity;
private String storeAddress;
private String storeField;
private String storeMail;
private String storePhone;
private String storeContact;
private String storeLongitude;
private String storeLatitude;
//get，set方法省略
}
@Entity
@Table(name = "wx_ap", catalog = "db_freeradius")
public class WeiXinAP extends BaseEntity implements java.io.Serializable {
/**
*
*/
private static final long serialVer sionUID = -227365820215202729L;
private Long id;
private Long hid;
private String ssid;
private String deviceMac;
private String bssid;
private Long deviceNo;
private String deviceModel;
private String bandWidth;
private String bandOpr;
private Integer storeId;
private String storeName;
private String brandName;
private String storeProvince;
private String storeCity;
private String storeAddress;
private String storeField;
private String storeMail;
private String storePhone;
private String storeContact;
private double storeLongitude;
private double storeLatitude;
private int status;
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "id", unique = true)
//省略get，set方法
}
使用BeanUtils.copyProperties(apDto,weiXinAP);方法就能把weixinAP对应的属性值赋给apDto,而weixinAP多余的字段不会对它作任何处理。
（PS当有的字段为null属性时，使用此方法会出现问题。例如int型的null使用此方法后对应的字段会变为0，如果你之后的业务逻辑有用null判断的情况，就会出现问题，这时候需要你去重写他的方法对为null的情况进行修改，建议使用spring中的BeanUtils）