BeanUtils工具类copyProperties方法缺点及解决
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2022-05-22 17:05:47
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。 ......
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。
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