Java copyProperties

最新推荐文章于 2025-07-28 15:55:58 发布

最新推荐文章于 2025-07-28 15:55:58 发布 · 339 阅读

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本文介绍了一种自定义的Bean拷贝方法，该方法不依赖于第三方库，通过反射机制实现了源Bean到目标Bean的属性复制。适用于属性类型相同的JavaBean对象。

自己写了个copyProperties方法，虽没apache与spring的强大，但功能自己够用就好，而且不用引入第三方库。

package bean;

import java.lang.reflect.Method;

/**
 * @version 1.0
 * @author fireinjava
 * @data Dec 11, 2009
 * @描述: 存放字段及其要用到的对应get(来自sourceBean)与set(来自targetBean)方法
 */
public class PropertyMethod {

	private String propertyName;
	private Method methodRead;
	private Method methodWrite;
	
	public String getPropertyName() {
		return propertyName;
	}
	public void setPropertyName(String propertyName) {
		this.propertyName = propertyName;
	}
	public Method getMethodRead() {
		return methodRead;
	}
	public void setMethodRead(Method methodRead) {
		this.methodRead = methodRead;
	}
	public Method getMethodWrite() {
		return methodWrite;
	}
	public void setMethodWrite(Method methodWrite) {
		this.methodWrite = methodWrite;
	}
	
}

package bean;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * @version 1.0
 * @author fireinjava
 * @data Dec 11, 2009
 * @描述:拷贝Bean(适用于标准JavaBean,且拷贝的属性类型必须一致)
 */
public class BeanUtils {
	
	public static void copyProperties(Object source, Object target) throws IllegalArgumentException,
			IllegalAccessException, InvocationTargetException {
		copyProperties(source, target, null);
	}

	/**
	 * 当某个属性不必复制或两个Bean属性名称一样且类型不一样时用(得另外设值)
	 */
	public static void copyProperties(Object source, Object target, String[] ignoreProperties)
			throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
		if (source == null)
			throw new IllegalArgumentException("Source must not be null");
		else if (target == null)
			throw new IllegalArgumentException("Target must not be null");

		List<String> ignoreList = null;
		if (ignoreProperties != null)
			ignoreList = Arrays.asList(ignoreProperties);

		List<PropertyMethod> listPm = new ArrayList<PropertyMethod>();
		Map<String, Method> mapMethodWrite = new HashMap<String, Method>();
		Map<String, Method> mapMethodRead = new HashMap<String, Method>();

		Method[] methodTarget = target.getClass().getMethods();
		for (Method mt : methodTarget)
			if (mt.getName().startsWith("set")) {
				String propertyName = mt.getName().substring(3, 4).toLowerCase() + mt.getName().substring(4);
				if (ignoreList == null || !ignoreList.contains(propertyName))
					mapMethodWrite.put(propertyName, mt);
			}

		Method[] methodSource = source.getClass().getMethods();
		for (Method ms : methodSource)
			if (ms.getName().startsWith("get"))
				mapMethodRead.put(ms.getName().substring(3, 4).toLowerCase() + ms.getName().substring(4), ms);
			else if (ms.getName().startsWith("is"))
				mapMethodRead.put(ms.getName().substring(2, 3).toLowerCase() + ms.getName().substring(3), ms);

		Iterator<String> iter = mapMethodWrite.keySet().iterator();
		while (iter.hasNext()) {
			String propertyName = iter.next();
			if (mapMethodRead.get(propertyName) != null) {
				PropertyMethod pm = new PropertyMethod();
				pm.setPropertyName(propertyName);
				pm.setMethodRead(mapMethodRead.get(propertyName));
				pm.setMethodWrite(mapMethodWrite.get(propertyName));
				listPm.add(pm);
			}
		}

		for (PropertyMethod pm : listPm) {
			Object[] obj = new Object[1];
			obj[0] = pm.getMethodRead().invoke(source, new Object[0]);
			pm.getMethodWrite().invoke(target, obj);
		}

	}
}

其中List<PropertyMethod> listPm = new ArrayList<PropertyMethod>();用来存放完整的属性及属性Get/set方法，不借助 PropertyMethod而直接用两个Map也可。

另外两种copyProperties:

org.apache.commons.beanutils.BeanUtils.copyProperties(target, source);

//source中的Timestamp类型属性值不可为null 否则会报错

org.springframework.beans.BeanUtils.copyProperties(source, target);