代码里面有注释：

import java.io.*;
import java.lang.reflect.Constructor;public class Hello implements  Cloneable,Serializable{private String str;public Hello(String str){this.str = str;}public  Hello(){this.str = "class";}public static void main(String[] args) throws Exception{Hello hello = Hello.getInstanceByNew();System.out.println(hello.str);System.out.println("=============================");try{Hello instanceByClone = Hello.getInstanceByClone(hello);System.out.println(instanceByClone.str);System.out.println(hello == instanceByClone);}catch (Exception e){e.printStackTrace();}System.out.println("=============================");Hello instanceByClass = Hello.getInstanceByClass();System.out.println(instanceByClass.str);System.out.println("=============================");System.out.println("使用无参构造");Hello instanceByConstructor = Hello.getInstanceByConstructor();System.out.println(instanceByConstructor.str);System.out.println("使用有参构造");Hello instanceByConstructor2 = Hello.getInstanceByConstructor("有参构造");System.out.println(instanceByConstructor2.str);System.out.println("=============================");/*** 首先 设置一个序列化文件位置*/String path = "hello.obj";ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(path));Hello xlh = new Hello("序列化");objectOutputStream.writeObject(xlh);objectOutputStream.close();/*** 反序列化拿到对象*/Hello instanceBySerializable = Hello.getInstanceBySerializable(path);System.out.println(instanceBySerializable.hashCode()+"******************");System.out.println(xlh.str);System.out.println(instanceBySerializable.str);System.out.println("结束");}/*** 使用 new*/public static Hello  getInstanceByNew(){return new Hello("new");}/*** 使用 clone 使用此方法 class类需要继承 cloneable 接口*/public static  Hello getInstanceByClone(Hello hello) throws CloneNotSupportedException{Hello clone1 = (Hello) hello.clone();return clone1;}/*** 使用Class的 newInstance 这个newInstance方法调用无参的构造函数创建对象*/public static Hello getInstanceByClass() throws Exception{Hello hello = (Hello) Class.forName("Hello").newInstance();return hello;}/*** 使用 构造器 无参函数*/public static Hello getInstanceByConstructor() throws Exception{Constructor<Hello> constructor = Hello.class.getConstructor();Hello hello = constructor.newInstance();return hello;}/*** 使用 构造器 有参函数*/public static Hello getInstanceByConstructor(String str) throws Exception{Constructor<Hello> constructor = Hello.class.getConstructor(String.class);Hello hello = constructor.newInstance(str);return hello;}/*** 使用反序列化 获取实例化对象  对象的类要继承 Serializable 接口表示可以进行序列化*/public static Hello getInstanceBySerializable(String path) throws  Exception{ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(path));Object o = objectInputStream.readObject();objectInputStream.close();System.out.println(o.hashCode()+"******************");return  (Hello) o;}
}