BeanUtils工具类copyProperties方法缺点及解决

使⽤类为spring-beans:4.3.13release包中的 org.springframework.beans.BeanUtilsBeanUtils.copyProperties(Object source, Object target);

该⽅法会将source中同名属性的值赋值给target中的同名属性。（前提是source中的改属性类型属于target中该属性类型【即为相同类或其⼦类，否则⽬标属性还是为原默认值】）import com.alibaba.fastjson.JSON;import lombok.Data;import org.junit.Test;

import org.springframework.beans.BeanUtils;import java.util.Arrays;import java.util.List;

/**

* @author

* @date 2019/10/26 */

public class BeanUtil {

public static void main(String[] args) { Bean2 bean2 = new Bean2(); bean2.setIntField(1); bean2.setStrField(\"str\"); bean2.setObjField(\"obj\");

bean2.setListIntegerField(Arrays.asList(\"1\ bean2.setObjField1(\"1\");

Bean1 bean1 = new Bean1();

//属性中有元素不满⾜⽬标属性时依旧赋值成功Bean1.listIntegerField），未对能强转成功的属性做赋值处理(Bean1.objField1) BeanUtils.copyProperties(bean2,bean1);

System.out.println(\"bean2:\\"+bean2); System.out.println(\"bean1:\\"+bean1);

System.out.println(\"bean1.getListIntegerField:\\"+bean1.getListIntegerField().get(0));//调⽤到具体异常元素再抛出异常 System.out.println(\"--------------------分割线--------------------\"); Bean1 bean11 = new Bean1(); bean11.setIntField(1); bean11.setStrField(\"str\"); bean11.setObjField(\"obj\");

bean11.setListIntegerField(Arrays.asList(1,2,3)); bean11.setObjField1(1);

Bean2 bean21 = new Bean2();

//Bean2.objField1 类型⼤于Bean1.objField1类型，赋值成功 BeanUtils.copyProperties(bean11,bean21);

System.out.println(\"bean11:\\"+bean11); System.out.println(\"bean21:\\"+bean21);

System.out.println(\"bean21.getListIntegerField:\\"+bean21.getListIntegerField());　　　/*

运⾏结果：

bean2: BeanUtil.Bean2(intField=1, strField=str, objField=obj, objField1=1, listIntegerField=[1, 2assdsdsf, 3]) bean1: BeanUtil.Bean1(intField=1, strField=str, objField=obj, objField1=null, listIntegerField=[1, 2assdsdsf, 3]) bean1.getListIntegerField: 1

--------------------分割线-------------------- bean11: BeanUtil.Bean1(intField=1, strField=str, objField=obj, objField1=1, listIntegerField=[1, 2, 3]) bean21: BeanUtil.Bean2(intField=1, strField=str, objField=obj, objField1=1, listIntegerField=[1, 2, 3]) bean21.getListIntegerField: [1, 2, 3]*/ }

@Test

public void optimizeCopyProperties(){ Bean2 bean2 = new Bean2(); bean2.setIntField(1); bean2.setStrField(\"str\"); bean2.setObjField(\"obj\");

// bean2.setListIntegerField(Arrays.asList(\"1assdsdsf\ bean2.setListIntegerField(Arrays.asList(\"1\ bean2.setObjField1(\"1\");

//借助json⼯具类，底层以字符串实现强转。对能强转成功的属性做赋值并赋值成功，若同名属性值强转赋值失败则抛出异常

Bean1 bean1 = JSON.parseObject(JSON.toJSONBytes(bean2), Bean1.class); System.out.println(\"bean2:\\"+bean2); System.out.println(\"bean1:\\"+bean1);

System.out.println(\"bean1.getListIntegerField:\\"+bean1.getListIntegerField());

/*　　运⾏结果：

bean2: BeanUtil.Bean2(intField=1, strField=str, objField=obj, objField1=1, listIntegerField=[1, 2, 3]) bean1: BeanUtil.Bean1(intField=1, strField=str, objField=obj, objField1=1, listIntegerField=[1, 2, 3]) bean1.getListIntegerField: [1, 2, 3]*/}

@Data

public static class Bean1{ private int intField; private String strField; private Object objField; private Integer objField1;

private List listIntegerField; }

@Data

public static class Bean2{ private int intField; private String strField; private Object objField; private Object objField1;

private List listIntegerField; }}

总结：可⽤阿⾥的json转换⼯具处理类似的属性赋值。其强转赋值对能⽤字符串强转的类型赋值更智能，属性元素的异常赋值检查也更严格。