首先要实现Cloneable接口,然后在重载clone方法,最后在clone()方法中调用了super.clone(),这也意味着无论clone类的继承结构是什么样的,super.clone()直接或间接调用了java.lang.Object类的clone()方法。
public class A implements Cloneable {
public String name;
public Object clone() {
A o = null;
try {
o = (A) super.clone();
} catch (CloneNotSupportedException e) {
e.printStackTrace();
}
return o;
}
}
public class A implements Cloneable {
public String name[];
public Vector<B> claB;
public A(){
name=new String[2];
claB=new Vector<B>();
}
public Object clone() {
A o = null;
try {
o = (A) super.clone();
o.name==(String[])name.clone();//深度clone
o.claB=new Vector<B>();//将clone进行到底
for(int i=0;i<claB.size();i++){
B temp=(B)claB.get(i).clone();//当然Class B也要实现相应clone方法
o.claB.add(temp);
}
} catch (CloneNotSupportedException e) {
e.printStackTrace();
}
return o;
}
}
ArrayLIst的clone():
public Object clone() {
try {
ArrayList<?> v = (ArrayList<?>) super.clone();
v.elementData = Arrays.copyOf(elementData, size);
v.modCount = 0;
return v;
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError(e);
}
}