Collection接口有多个方法。List接口扩展了Collection接口,并声明了与Collection接口相同的方法。为什么会这样呢?
举个例子:
interface Collection extends Iterable
{
public abstract int size();
public abstract boolean isEmpty();
public abstract boolean contains(java.lang.Object);
public abstract java.util.Iterator<E> iterator();
public abstract java.lang.Object[] toArray();
public abstract <T extends java/lang/Object> T[] toArray(T[]);
public abstract boolean add(E);
public abstract boolean remove(java.lang.Object);
public abstract boolean containsAll(java.util.Collection<?>);
public abstract boolean addAll(java.util.Collection<? extends E>);
public abstract boolean removeAll(java.util.Collection<?>);
public abstract boolean retainAll(java.util.Collection<?>);
public abstract void clear();
public abstract boolean equals(java.lang.Object);
public abstract int hashCode();
}
同样的方法也存在于List接口中:
public interface List extends Collection
{
public abstract int size();
public abstract boolean isEmpty();
public abstract boolean contains(java.lang.Object);
public abstract java.util.Iterator<E> iterator();
public abstract java.lang.Object[] toArray();
public abstract <T extends java/lang/Object> T[] toArray(T[]);
public abstract boolean add(E);
public abstract boolean remove(java.lang.Object);
public abstract boolean containsAll(java.util.Collection<?>);
public abstract boolean addAll(java.util.Collection<? extends E>);
public abstract boolean removeAll(java.util.Collection<?>);
public abstract boolean retainAll(java.util.Collection<?>);
public abstract void clear();
public abstract boolean equals(java.lang.Object);
public abstract int hashCode();
}
如果List已经扩展了Collection接口,那么是否需要在List中重新编写这些方法?
.class
文件吗? - chrylis -cautiouslyoptimistic-