1:属性类型不一致导致拷贝失败
public class BeanUtilsTest {
public static void main(String[] args) {
SourcePoJo sourcePoJo = new SourcePoJo("jingdong", (long) 35711);
TargetPoJo targetPoJo = new TargetPoJo();
BeanUtils.copyProperties(sourcePoJo,targetPoJo);
System.out.println(targetPoJo);
}
}
@Data
@AllArgsConstructor
class SourcePoJo{
private String username;
private Long id;
}
@Data
class TargetPoJo{
private String username;
private String id;
}
public class BeanUtilsTest {
public static void main(String[] args) {
SourcePoJo sourcePoJo = new SourcePoJo();
sourcePoJo.setUsername("joy");
TargetPoJo targetPoJo = new TargetPoJo();
BeanUtils.copyProperties(sourcePoJo,targetPoJo);
System.out.println(targetPoJo);
}
}
@Data
class SourcePoJo{
private String username;
private Long id;
}
@Data
class TargetPoJo{
private String username;
private long id;
}
2:null值覆盖导致数据异常
public class BeanUtilsTest {
public static void main(String[] args) {
SourcePoJo sourcePoJo = new SourcePoJo();
sourcePoJo.setId("35711");
TargetPoJo targetPoJo = new TargetPoJo();
targetPoJo.setUsername("Joy");
BeanUtils.copyProperties(sourcePoJo,targetPoJo);
System.out.println(targetPoJo);
}
}
@Data
class SourcePoJo{
private String username;
private String id;
}
@Data
class TargetPoJo{
private String username;
private String id;
}
3:导包错误导致拷贝数据异常
//org.springframework.beans.BeanUtils(源对象在左边,目标对象在右边)
public static void copyProperties(Object source, Object target) throws BeansException
//org.apache.commons.beanutils.BeanUtils(源对象在右边,目标对象在左边)
public static void copyProperties(Object dest, Object orig) throws IllegalAccessException, InvocationTargetException
4:查找不到字段引用,修改内容难以溯源
5:内部类数据无法成功拷贝
public class BeanUtilsTest {
public static void main(String[] args) {
SourcePoJo sourcePoJo = new SourcePoJo();
sourcePoJo.setUsername("joy");
SourcePoJo.InnerClass innerClass = new SourcePoJo.InnerClass("sourceInner");
sourcePoJo.innerClass=innerClass;
System.out.println(sourcePoJo.toString());
TargetPoJo targetPoJo = new TargetPoJo();
BeanUtils.copyProperties(sourcePoJo,targetPoJo);
System.out.println(targetPoJo.toString());
}
}
//下面是类的信息,这里就直接放到一块展示了
@Data
@ToString
public class SourcePoJo{
private String username;
private Long id;
public InnerClass innerClass;
@Data
@ToString
@AllArgsConstructor
public static class InnerClass{
public String innerName;
}
}
@Data
@ToString
public class TargetPoJo{
private String username;
private Long id;
public InnerClass innerClass;
@Data
@ToString
public static class InnerClass{
public String innerName;
}
}
6:BeanUtils.copyProperties是浅拷贝
public class BeanUtilsTest {
public static void main(String[] args) {
Person sourcePerson = new Person("sunyangwei",new Card("123456"));
Person targetPerson = new Person();
BeanUtils.copyProperties(sourcePerson, targetPerson);
sourcePerson.getCard().setNum("35711");
System.out.println(targetPerson);
}
}
class Card {
private String num;
}
class Person {
private String name;
private Card card;
}
7:底层实现为反射拷贝效率低
public class BeanUtilsTest {
public static void main(String[] args) {
long copyStartTime = System.currentTimeMillis();
User sourceUser = new User("sunyangwei");
User targetUser = new User();
for(int i = 0; i < 10000; i++) {
BeanUtils.copyProperties(sourceUser, targetUser);
}
System.out.println("copy方式:"+(System.currentTimeMillis()-copyStartTime));
long setStartTime = System.currentTimeMillis();
for(int i = 0; i < 10000; i++) {
targetUser.setUserName(sourceUser.getUserName());
}
System.out.println("set方式:"+(System.currentTimeMillis()-setStartTime));
}
}
class User{
private String userName;
}
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