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
SourceDemo
package com.fortis.customer.test; import java.util.Date; import org.apache.commons.lang3.builder.ToStringBuilder; public class SourceDemo { private int id; private String name; private String address; private Date createTime; public int getId() { return id; } public void setId(int id) { this.id = 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 class TargetDemo { private Integer id; private String name; private String email; private Date createTime; public Integer getId() { return id; } public void setId(Integer id) { this.id = 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 class Test { 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] [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
SourceDemo
package com.fortis.customer.test; import java.util.Date; import org.apache.commons.lang3.builder.ToStringBuilder; public class SourceDemo { private int id; private String name; private String address; private Date createTime; public int getId() { return id; } public void setId(int id) { this.id = 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 class TargetDemo { private Integer id; private String name; private String email; private String createTime; public Integer getId() { return id; } public void setId(Integer id) { this.id = 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 class Test { 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
Test
package com.fortis.customer.test; import java.lang.reflect.InvocationTargetException; import java.util.Date; public class Test { 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
[id=10,name=姓名,email=<null>,createTime=Thu Jan 01 08:00:00 CST 1970]
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
[id=10,name=姓名,email=,createTime=1970-01-01]
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
SourceDemo
package com.fortis.customer.test; import org.apache.commons.lang3.builder.ToStringBuilder; public class SourceDemo { private int id; private String name; private String address; private String createTime; public int getId() { return id; } public void setId(int id) { this.id = 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 class TargetDemo { private Integer id; private String name; private String email; private Date createTime; public Integer getId() { return id; } public void setId(Integer id) { this.id = 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 class Test { 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
Test
package com.fortis.customer.test;
import java.lang.reflect.InvocationTargetException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Test {
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 [yyyy-MM-dd] 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