java


(1) 用new语句创建对象,这是最常见的创建对象的方法。
(2) 运用反射手段,调用java.lang.Class或者java.lang.reflect.Constructor类的newInstance()实例方法。
(3) 调用对象的clone()方法。
(4) 运用反序列化手段,调用java.io.ObjectInputStream对象的 readObject()方法。

 

一.用new语句创建对象

User user = new User()

 

二.运用反射手段
(1)调用java.lang.Class.newInstance()

Class.forName(classname).newInstance()
Wife wife = (Wife) Class.forName("com.java.clone.Wife").newInstance();

 

 (2)调用java.lang.reflect.Constructor类的newInstance()

Constructor<Wife> constructor = Wife.class.getDeclaredConstructor(int.class,String.class);
Wife wife = (Wife) constructor.newInstance(1,"nihao");

 

三.调用对象的clone()方法
详情参考:http://ncs123.iteye.com/blog/1775631

 

Wife wife = new Wife(1,"wang");
Wife wife2 = null;
wife2 = (Wife) wife.clone();//运用clone()方法产生新对象

 

四.运用反序列化手段
被序列化的对象必须implements Serializable

public class BeanUtil {

	@SuppressWarnings("unchecked")
	public static <T> T cloneTo(T src) throws RuntimeException {
		ByteArrayOutputStream memoryBuffer = new ByteArrayOutputStream();
		ObjectOutputStream out = null;
		ObjectInputStream in = null;
		T dist = null;

		try {
			out = new ObjectOutputStream(memoryBuffer);
			out.writeObject(src);
			out.flush();
			in = new ObjectInputStream(new ByteArrayInputStream(
					memoryBuffer.toByteArray()));
			dist = (T) in.readObject();

		} catch (Exception e) {
			throw new RuntimeException(e);
		} finally {
			if (out != null)
				try {
					out.close();
					out = null;
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			if (in != null)
				try {
					in.close();
					in = null;
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
		}

		return dist;
	}

	public static void main(String[] args){
		Husband husband = new Husband(1);
		Wife wife = new Wife(1,"jin");
		husband.setWife(wife);
		Husband husband2 = cloneTo(husband);//运用反序列生成了一个对象
	}
}

 

 

 

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