BeanUtil 中copyProperties分析

1. BeanUtil 类继承了 PropertyUtils 类：源代码：

public class BeanUtil extends PropertyUtils

 

2. 源代码如下，有小部份中文注释：

	/**
	 * override BeanUtils method copyProperties, support not copy null or blank
	 * property
	 *
	 * @param dest
	 * @param src
	 * @throws IllegalAccessException
	 * @throws InvocationTargetException
	 * @throws IllegalArgumentException
	 */

	public static void copyProperties(Object dest, Object src) {
		// 为两个参数时，skipNull 默认为true
		copyProperties(dest, src, true);
	}

	/**
	 * override BeanUtils method copyProperties, support not copy null or blank
	 * property
	 *
	 * @param dest
	 * @param src
	 * @throws IllegalAccessException
	 * @throws InvocationTargetException
	 * @throws IllegalArgumentException
	 */
	public static void copyProperties(Object dest, Object src, boolean skipNull) {
		// Validate existence of the specified beans
		if (dest == null) {
			throw new IllegalArgumentException("No destination bean specified");
		}

		if (src == null) {
			throw new IllegalArgumentException("No origin bean specified");
		}
		// 获取所有src中的属性，存入于数组中
		PropertyDescriptor[] origDescriptors = PropertyUtils
				.getPropertyDescriptors(src);
		
		for (int i = 0; i < origDescriptors.length; i++) {
			// 取出src中属性名
			String name = origDescriptors[i].getName();

			if ("class".equals(name)) {
				continue; // No point in trying to set an object's class
			}

			if (PropertyUtils.isReadable(src, name)
					&& PropertyUtils.isWriteable(dest, name)) {

				Object value = null;
				try {
					// 取出属性的值
					value = PropertyUtils.getSimpleProperty(src, name);
				} catch (Exception e) {
					throw new RuntimeException();
				}

				if (skipNull) {
					if (value == null) {
						continue;
					}
				} else if (value == null){
						value = null;
				}

				try {
					//copyProperties(dest, name, value);
					setProperty(dest, name, value);
				} catch (Exception e) {
					throw new RuntimeException();
				}
			}
		}
	}

  使用方法很简单。

 

评论

1 楼 bo_hai 2011-11-07  

使用PropertyUtils时，需求又下jar文件：
1、log4j.jar、commons-beanutils.jar、commons-logging-commons-logging.jar；