什麼是 BeanUtils？

官方解釋

Commons BeanUtils
Most Java developers are used to creating Java classes that conform to the JavaBeans naming patterns for property getters and setters. It is natural to then access these methods directly, using calls to the corresponding getXxx and setXxx methods. However, there are some occasions where dynamic access to Java object properties (without compiled-in knowledge of the property getter and setter methods to be called) is needed. Example use cases include:

Building scripting languages that interact with the Java object model (such as the Bean Scripting Framework).
Building template language processors for web presentation and similar uses (such as JSP or Velocity).
Building custom tag libraries for JSP and XSP environments (such as Jakarta Taglibs, Struts, Cocoon).
Consuming XML-based configuration resources (such as Ant build scripts, web application deployment descriptors, Tomcat’s server.xml file).
The Java language provides Reflection and Introspection APIs (see the java.lang.reflect and java.beans packages in the JDK Javadocs). However, these APIs can be quite complex to understand and utilize. The BeanUtils component provides easy-to-use wrappers around these capabilities.

個人理解

Apache的Commons包中的BeanUtils工具類，提供了對於JavaBean進行各種操作， 比如物件,屬性複製等。

• 克隆JavaBean
  cloneBean(final Object bean)
  傳入需要克隆的JavaBean，會返回一個克隆後的JavaBean，且原JavaBean不變。
• JavaBean2Map
  describe(final Object bean)
  傳入需要轉換的JavaBean，會返回一個Map<String, String>的集合，原JavaBean不變；
  P.S.：該方法會將JavaBean的所有屬性進行轉換，包括父類的屬性。