[JAVA] Apache Commons BeanUtils fit point

A note of what happened when using Apache Commons BeanUtils

Confirmed version
verification code

Bean.java

public class Bean {
	private Timestamp timestamp;

	public Timestamp getTimestamp() {
		return timestamp;
	}
	public void setTimestamp(Timestamp timestamp) {
		this.timestamp = timestamp;
	}
}

Main.java

public class Main {
	public static void main(String[] args) throws Exception {
		Bean bean = new Bean();

		// 1.9.Prior to 3, Object.getClass()Is interpreted as an accessor"class"Is included in the property list.
		BeanUtils.describe(bean);
		// => 1.9.Before 3:{class=class test.Bean, timestamp=null}
		//    1.9.4:{timestamp=null}
		// ※ PropertyUtils.describe(bean)Will give the same result.

		// 1.9.Before 3, the behavior when setting an inaccessible property with setProperty and copyProperty is different.
		BeanUtils.setProperty(bean, "class", Bean.class);
		// =>Nothing is done.
		BeanUtils.copyProperty(bean, "class", Bean.class);
		// => 1.9.Before 3: java.lang.reflect.InvocationTargetException:Cannot set class occurs.
		//    1.9.4: Nothing is executed.(BEANUTILS-Has the behavior changed due to the influence of 520? )

		//The behavior when trying to set null for some types of properties is different between setProperty and copyProperty.
		BeanUtils.setProperty(bean, "timestamp", null);
		// => org.apache.commons.beanutils.ConversionException: No value specified for 'java.sql.Timestamp'Occurs.
		BeanUtils.copyProperty(bean, "timestamp", null);
		// => 1.8.Before 3: A ConversionException occurred like copyProperty.
		//    1.9.After 0: Nothing is executed.(BEANUTILS-Fixed in 454)
	}
}
reference

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