使用类为spring-beans:4.3.13release包中的 org.springframework.beans.BeanUtils
BeanUtils.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","2assdsdsf","3")); 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:\t"+bean2); System.out.println("bean1:\t"+bean1); System.out.println("bean1.getListIntegerField:\t"+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:\t"+bean11); System.out.println("bean21:\t"+bean21); System.out.println("bean21.getListIntegerField:\t"+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","2","3")); bean2.setListIntegerField(Arrays.asList("1","2","3")); 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:\t"+bean2); System.out.println("bean1:\t"+bean1); System.out.println("bean1.getListIntegerField:\t"+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<Integer> listIntegerField;
}
@Data
public static class Bean2{
private int intField;
private String strField;
private Object objField;
private Object objField1;
private List<String> 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。