org.springframework.beans.BeanUtils与org.apache.commons.beanutils.BeanUtils的copyP
知识点org.springframework.beans.BeanUtils与org.apache.commons.beanutils.BeanUtils都提供了copyProperties方法，作用是将一个Bean对象中的数据封装到另一个属性结构相似的Bean对象中
1）两者的copyProperties方法参数位置不同
org.springframework.beans.BeanUtils: copyProperties(sourceDemo, targetDemo)
org.apache.commons.beanutils.BeanUtils: copyProperties(targetDemo, sourceDemo)
2）要求两个Bean的属性名相同，且有对应的setXxx方法和getXxx方法。其实底层原理是使用sourceDemo的getXxx方法和targetDemo的setXxx方法
3）sourceDemo有的属性而targetDemo没有的属性，不会封装到targetDemo对象中；
targetDemo有的属性而sourceDemo没有的属性，会封装到targetDemo中，数据为默认值（注意基本类型默认值与引用类型默认值不同）
4）类型转换问题
a）基本类型与其对应的封装类型可以相互转换
b）org.springframework.beans.BeanUtils与org.apache.commons.beanutils.BeanUtils对于String和Date类型转换的情况是不同的，具体看以下案例
案例一
SourceDemo
package com.fortis.customer.test;
import java.util.Date;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private int>
private String name;
private String address;
private Date createTime;
public int getId() {
return>
}
public void setId(int>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
TargetDemo
package com.fortis.customer.test;
import java.util.Date;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private Integer>
private String name;
private String email;
private Date createTime;
public Integer getId() {
return>
}
public void setId(Integer>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.util.Date;
public>
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException {
SourceDemo sourceDemo
= new SourceDemo();
sourceDemo.setId(
10);
sourceDemo.setName(
"姓名");
sourceDemo.setAddress(
"地址");
sourceDemo.setCreateTime(
new Date());
TargetDemo targetDemo
= new TargetDemo();
org.springframework.beans.BeanUtils.copyProperties(sourceDemo, targetDemo);
System.
out.println(targetDemo);
org.apache.commons.beanutils.BeanUtils.copyProperties(targetDemo, sourceDemo);
System.
out.println(targetDemo);
}
}
测试效果：
[id
=10,name=姓名,email=<null>,createTime=Fri Jun 30 16:19:31 CST 2017]
结论：基本类型与其对应的封装类型是可以相互转换的
案例二
SourceDemo
package com.fortis.customer.test;
import java.util.Date;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private int>
private String name;
private String address;
private Date createTime;
public int getId() {
return>
}
public void setId(int>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
TargetDemo
package com.fortis.customer.test;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private Integer>
private String name;
private String email;
private String createTime;
public Integer getId() {
return>
}
public void setId(Integer>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getCreateTime() {
return createTime;
}
public void setCreateTime(String createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.util.Date;
public>
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException {
SourceDemo sourceDemo
= new SourceDemo();
sourceDemo.setId(
10);
sourceDemo.setName(
"姓名");
sourceDemo.setAddress(
"地址");
sourceDemo.setCreateTime(
new Date(0));
TargetDemo targetDemo
= new TargetDemo();
org.springframework.beans.BeanUtils.copyProperties(sourceDemo, targetDemo);
System.
out.println(targetDemo);
//org.apache.commons.beanutils.BeanUtils.copyProperties(targetDemo, sourceDemo);
//System.out.println(targetDemo);
}
}
测试效果：
Exception in thread "main" org.springframework.beans.FatalBeanException: Could not copy properties from source to target; nested exception is java.lang.IllegalArgumentException: argument type mismatch
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
599)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
509)
at com.fortis.customer.test.Test.main(Test.java:
17)
Caused by: java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
596)
...
2 more
结论：org.springframework.beans.BeanUtils.copyProperties不可以将java.util.Date类型转换成String类型
同时：也不可将java.sql.Date类型转换成String类型（因为网上搜的说可以支持java.sql.Date类型，我自己测试了一下发现不可以，还是信自己靠谱）
Exception in thread "main" org.springframework.beans.FatalBeanException: Could not copy properties from source to target; nested exception is java.lang.IllegalArgumentException: argument type mismatch
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
599)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
509)
at com.fortis.customer.test.Test.main(Test.java:
17)
Caused by: java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
596)
...
2 more
案例三
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.util.Date;
public>
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException {
SourceDemo sourceDemo
= new SourceDemo();
sourceDemo.setId(
10);
sourceDemo.setName(
"姓名");
sourceDemo.setAddress(
"地址");
sourceDemo.setCreateTime(
new Date(0));
TargetDemo targetDemo
= new TargetDemo();
//org.springframework.beans.BeanUtils.copyProperties(sourceDemo, targetDemo);
//System.out.println(targetDemo);
org.apache.commons.beanutils.BeanUtils.copyProperties(targetDemo, sourceDemo);
System.out.println(targetDemo);
}
}
注：SourceDemo和TargetDemo与案例二相同
测试效果：java.util.Date
结论：org.apache.commons.beanutils.BeanUtils.copyProperties可以将java.util.Date类型转换成String类型
测试效果：java.sql.Date
结论：org.apache.commons.beanutils.BeanUtils.copyProperties可以将java.sql.Date类型转换成String类型
注意：虽然都可以转换，但发现两者的日期格式还是不同的
案例四：
SourceDemo
package com.fortis.customer.test;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private int>
private String name;
private String address;
private String createTime;
public int getId() {
return>
}
public void setId(int>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getCreateTime() {
return createTime;
}
public void setCreateTime(String createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
TargetDemo
package com.fortis.customer.test;
import java.util.Date;
import org.apache.commons.lang3.builder.ToStringBuilder;
public>
private Integer>
private String name;
private String email;
private Date createTime;
public Integer getId() {
return>
}
public void setId(Integer>
this.id =>
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.text.SimpleDateFormat;
import java.util.Date;
public>
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException {
SourceDemo sourceDemo
= new SourceDemo();
sourceDemo.setId(
10);
sourceDemo.setName(
"姓名");
sourceDemo.setAddress(
"地址");
sourceDemo.setCreateTime(
new SimpleDateFormat("yyyyMMddHHmmss").format(new Date(0)));
TargetDemo targetDemo
= new TargetDemo();
org.springframework.beans.BeanUtils.copyProperties(sourceDemo, targetDemo);
System.out.println(targetDemo);
//org.apache.commons.beanutils.BeanUtils.copyProperties(targetDemo, sourceDemo);
//System.out.println(targetDemo);
}
}
测试效果：
Exception in thread "main" org.springframework.beans.FatalBeanException: Could not copy properties from source to target; nested exception is java.lang.IllegalArgumentException: argument type mismatch
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
599)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
509)
at com.fortis.customer.test.Test.main(Test.java:
18)
Caused by: java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.beans.BeanUtils.copyProperties(BeanUtils.java:
596)
...
2 more
结论：org.springframework.beans.BeanUtils.copyProperties不可以将String类型转换成java.util.Date类型
同时：也不可将String类型转换成java.sql.Date类型
案例五
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.text.SimpleDateFormat;
import java.util.Date;
public>
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException {
SourceDemo sourceDemo = new SourceDemo();
sourceDemo.setId(10);
sourceDemo.setName("姓名");
sourceDemo.setAddress("地址");
sourceDemo.setCreateTime(new SimpleDateFormat("yyyyMMddHHmmss").format(new Date(0)));
TargetDemo targetDemo = new TargetDemo();
//org.springframework.beans.BeanUtils.copyProperties(sourceDemo, targetDemo);
//System.out.println(targetDemo);
org.apache.commons.beanutils.BeanUtils.copyProperties(targetDemo, sourceDemo);
System.out.println(targetDemo);
}
}
测试效果：java.util.Date
log4j:WARN No appenders could be found for logger (org.apache.commons.beanutils.converters.BooleanConverter).
log4j:WARN Please initialize the log4j system properly.
Exception
in thread "main" org.apache.commons.beanutils.ConversionException: DateConverter does not support default String to 'Date' conversion.
at org.apache.commons.beanutils.converters.DateTimeConverter.toDate(DateTimeConverter.java:
468)
at org.apache.commons.beanutils.converters.DateTimeConverter.convertToType(DateTimeConverter.java:
343)
at org.apache.commons.beanutils.converters.AbstractConverter.convert(AbstractConverter.java:
156)
at org.apache.commons.beanutils.converters.ConverterFacade.convert(ConverterFacade.java:
60)
at org.apache.commons.beanutils.BeanUtilsBean.convert(BeanUtilsBean.java:
1078)
at org.apache.commons.beanutils.BeanUtilsBean.copyProperty(BeanUtilsBean.java:
437)
at org.apache.commons.beanutils.BeanUtilsBean.copyProperties(BeanUtilsBean.java:
286)
at org.apache.commons.beanutils.BeanUtils.copyProperties(BeanUtils.java:
137)
at com.fortis.customer.test.Test.main(Test.java:
21)
结论：org.apache.commons.beanutils.BeanUtils
看错误日志，发现说是默认的转换器是不可以将String类型转换成java.util.Date，可能自己配置一个转换器就可以转了吧，我没有测试过
测试效果：java.sql.Date
log4j:WARN No appenders could be found for logger (org.apache.commons.beanutils.converters.BooleanConverter).
log4j:WARN Please initialize the log4j system properly.
Exception
in thread "main" org.apache.commons.beanutils.ConversionException: String must be in JDBC format to create a java.sql.Date
at org.apache.commons.beanutils.converters.DateTimeConverter.toDate(DateTimeConverter.java:
436)
at org.apache.commons.beanutils.converters.DateTimeConverter.convertToType(DateTimeConverter.java:
343)
at org.apache.commons.beanutils.converters.AbstractConverter.convert(AbstractConverter.java:
156)
at org.apache.commons.beanutils.converters.ConverterFacade.convert(ConverterFacade.java:
60)
at org.apache.commons.beanutils.BeanUtilsBean.convert(BeanUtilsBean.java:
1078)
at org.apache.commons.beanutils.BeanUtilsBean.copyProperty(BeanUtilsBean.java:
437)
at org.apache.commons.beanutils.BeanUtilsBean.copyProperties(BeanUtilsBean.java:
286)
at org.apache.commons.beanutils.BeanUtils.copyProperties(BeanUtils.java:
137)
at com.fortis.customer.test.Test.main(Test.java:
21)
结论：org.apache.commons.beanutils.BeanUtils
看错误日志，发现说是需要将String类型转成java.sql.Date，使用simpleDateFormat是将String类型转成java.util.Date，可能转成java.sql.Date就可以了吧，我没测试过
注意：我这里说的转换，单纯是指这一行代码sourceDemo.setCreateTime(new SimpleDateFormat("yyyyMMddHHmmss").format(new Date(0)));而不是两个Bean的类型转换
总之，无论是org.springframework.beans.BeanUtils还是org.apache.commons.beanutils.BeanUtils，默认情况下都不能将String类型转成Date类型
案例六：
SourceDemo：
private String name;
TargetDemo：
private String name = “马超”;
private String email = "张飞";
复制之后的结果：name = null，email = “张飞”
SourceDemo：
private String name = “诸葛亮”;
TargetDemo：
private String name = “马超”;
private String email = "张飞";
复制之后的结果：name = “诸葛亮”，email = “张飞”
注：使用两种BeanUtils效果相同
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