有4种显式地创建对象的方式：
1.用);
System.out.println("call default constructor");
}
public Customer(String name,int age){
this.name=name;
this.age=age;
System.out.println("call second constructor");
}
public Object clone()throws CloneNotSupportedException{
return super.clone();
}
public boolean equals(Object o){
if(this==o)return true;
if(! (o instanceof Customer)) return false;
final Customer other=(Customer)o;
if(this.name.equals(other.name) && this.age==other.age)
return true;
else
return false;
}
public String toString(){
return "name="+name+",age="+age;
}
public static void main(String args[])throws Exception{
//运用反射手段创建Customer对象
Class objClass=Class.forName("Customer");
Customer c1=(Customer)objClass.newInstance(); //会调用Customer类的默认构造方法
System.out.println("c1: "+c1); //打印name=unknown,age=0
//用new语句创建Customer对象
Customer c2=new Customer("Tom",20);
System.out.println("c2: "+c2); //打印name=tom,age=20
//运用克隆手段创建Customer对象
Customer c3=(Customer)c2.clone(); //不会调用Customer类的构造方法
System.out.println("c2==c3 : "+(c2==c3)); //打印false
System.out.println("c2.equals(c3) : "+c2.equals(c3)); //打印true
System.out.println("c3: "+c3); //打印name=tom,age=20
}
}