创建对象的4种方式

Posted 2020-08-26 明天，你好--飞翔的鱼

/**
* <p>
* Title: 创建对象的四种方式
* </p>
*
*
* @author lwx
* @version 1.0
* @create 2013 1 17 14:03:35
*/
public class CreateObj implements Cloneable,Serializable{
private static String filename = CreateObj.class.getResource("").getPath()
+ "/obj.txt";
static File file = new File(filename);
static {
if (!file.exists())
try {
file.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public static void main(String[] args) throws Exception {
// 1.第一种常用方式
CreateObj s1 = new CreateObj();
System.out.println(s1);
// 2.第二种方式 静态方式 java.lang.InstantiationException
CreateObj s2 = (CreateObj) Class.forName(
"com.newland.commons.collectionutil.CreateObj").newInstance();
System.out.println(s2);
//第三种方式 用对象流来实现 前提是对象必须实现 Serializable
ObjectOutputStream objectOutputStream = new ObjectOutputStream(
new FileOutputStream(filename));
objectOutputStream.writeObject(s2);
ObjectInput input=new ObjectInputStream(new FileInputStream(filename));
CreateObj s3 = (CreateObj) input.readObject();
System.out.println(s3);
//第四种 clone 必须 实现Cloneable接口 否则抛出CloneNotSupportedException
CreateObj obj=new CreateObj();
CreateObj s4= (CreateObj) obj.clone();
System.out.println(s4);
}
}