以继承的硬编码方式实现的代理

package question3;import java.util.ArrayList;import java.util.Collection;import java.util.Iterator;import java.util.List;import java.util.ListIterator;/* * 写一个ArrayList类的代理，其内部实现和ArrayList中完全相同的功能， * 并可以计算每个方法运行的时间。 *  *  解题方式一 *  1.通过实现一个List接口来获得ArrayList的List代理功能 *  2.为每一个list接口的方法实现代理调用 *  3.为每一个list接口的方法输出运行时间，单位为纳秒ns *  4.测试每一个方法的调用耗时 *   *  优点：抛弃了传统的继承覆盖机制，更灵活的代理和目标代码 *     转换 *  缺点：该方式会使代码量成倍递增，维护不便 *   *  注：1秒=1 000 000 000纳秒 jdk api中以毫微秒表示纳秒 */public class ArrayListProxy_1<E> implements List<E>{/** * 此代理的目标ArrayList,该成员只有代理类 * 可以持有，所以不应该暴露给用户，而是私有 */private ArrayList<E> list = new ArrayList<E>();/** * 缓冲的耗时变量，用来统计方法的耗时 * 单位为纳秒（毫微秒） *  * 该变量的提升方式在多线程环境会产生错误 * 并导致时间不准确,多线程中应该使其局部化 */private long taken;public static void main(String[] args){/* * 顶一个ArrayList实现的cellection实例， * 并用来测试该代理的参数为cellection的方法 * 也用来保证集合中有效元素的个数 */ArrayList<String> arrayList = new ArrayList<String>();arrayList.add("a");arrayList.add("b");arrayList.add("c");/* * 创建一个代理List，该实现可以以config的方法进行配置 * 实现代理和真实目标的转换 *  * 但是该方式无法实现ArrayList的本地方法调用，只能实现 * ArrayList上层接口的方法调用 */List<String> list = new ArrayListProxy_1<String>();list.size();list.isEmpty();list.contains("zhangsan");list.iterator();list.toArray();list.toArray(new String[]{});list.add("wangwu");list.remove("lisi");list.containsAll(arrayList);list.addAll(arrayList);list.indexOf("a");list.lastIndexOf("c");list.addAll(0,arrayList);list.get(0);list.set(0, "loli");list.removeAll(arrayList);list.retainAll(arrayList);list.clear();list.add(0, "tom");list.remove(0);list.listIterator();list.listIterator(0);list.subList(0, 00);}/* * 为每一个方法编写代理方式，并实现 * 以单位为纳秒的精确时间统计 * System.currentTimeMillis()在 * 精度上会有损失，低于100毫秒时， * 精度会有+5 -5之间的偏差 *  * After here, the other methods look like the same * 后边的不用看了。。。都一样的 */@Override    public int size()    {int returnValue;taken = System.nanoTime();returnValue = list.size();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".size() -> "+this.list.getClass().getName()+".size() times taken by "+taken+" ns");    return returnValue;    }@Override    public boolean isEmpty()    {boolean returnValue;taken = System.nanoTime();returnValue = list.isEmpty();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".isEmpty() -> "+this.list.getClass().getName()+".isEmpty() times taken by "+taken+" ns");    return returnValue;    }@Override    public boolean contains(Object o)    {boolean returnValue;taken = System.nanoTime();returnValue = list.contains(o);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".contains(Object) -> "+this.list.getClass().getName()+".contains(Object) times taken by "+taken+" ns");    return returnValue;    }@Override    public Iterator<E> iterator()    {Iterator<E> iterator;taken = System.nanoTime();iterator = list.iterator();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".iterator() -> "+this.list.getClass().getName()+".iterator() times taken by "+taken+" ns");    return iterator;    }@Override    public Object[] toArray()    {Object[] objs;taken = System.nanoTime();objs = list.toArray();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".toArray() -> "+this.list.getClass().getName()+".toArray() times taken by "+taken+" ns");    return objs;    }@Override    public <T> T[] toArray(T[] a)    {T[] objs;taken = System.nanoTime();objs = list.toArray(a);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".toArray(T[]) -> "+this.list.getClass().getName()+".toArray(T[]) times taken by "+taken+" ns");    return objs;    }@Override    public boolean add(E e)    {boolean returnValue;taken = System.nanoTime();returnValue = list.add(e);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".add(E) -> "+this.list.getClass().getName()+".add(E) times taken by "+taken+" ns");    return returnValue;    }@Override    public boolean remove(Object o)    {boolean returnValue;taken = System.nanoTime();returnValue = list.remove(o);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".remove(Object o) -> "+this.list.getClass().getName()+".remove(Object o) times taken by "+taken+" ns");    return returnValue;    }@Override    public boolean containsAll(Collection<?> c)    {boolean returnValue;taken = System.nanoTime();returnValue = list.containsAll(c);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".containsAll(Collection) -> "+this.list.getClass().getName()+".containsAll(Collection) times taken by "+taken+" ns");    return returnValue;}@Override    public boolean addAll(Collection<? extends E> c)    {boolean returnValue;taken = System.nanoTime();returnValue = list.addAll(c);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".addAll(Collection) -> "+this.list.getClass().getName()+".addAll(Collection) times taken by "+taken+" ns");return returnValue;    }@Override    public boolean addAll(int index, Collection<? extends E> c)    {boolean returnValue;taken = System.nanoTime();returnValue = list.addAll(index,c);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".addAll(int,Collection) -> "+this.list.getClass().getName()+".addAll(int,Collection) times taken by "+taken+" ns");return returnValue;    }@Override    public boolean removeAll(Collection<?> c)    {boolean returnValue;taken = System.nanoTime();returnValue = list.removeAll(c);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".removeAll(Collection) -> "+this.list.getClass().getName()+".removeAll(Collection) times taken by "+taken+" ns");return returnValue;    }@Override    public boolean retainAll(Collection<?> c)    {boolean returnValue;taken = System.nanoTime();returnValue = list.retainAll(c);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".retainAll(Collection) -> "+this.list.getClass().getName()+".retainAll(Collection) times taken by "+taken+" ns");return returnValue;    }@Override    public void clear()    {taken = System.nanoTime();list.clear();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".clear() -> "+this.list.getClass().getName()+".clear() times taken by "+taken+" ns");    }@Override    public E get(int index)    {E returnValue;taken = System.nanoTime();returnValue = list.get(index);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".get(int) -> "+this.list.getClass().getName()+".get(int) times taken by "+taken+" ns");return returnValue;    }@Override    public E set(int index, E element)    {E returnValue;taken = System.nanoTime();returnValue = list.set(index,element);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".set(int,E) -> "+this.list.getClass().getName()+".set(int,E) times taken by "+taken+" ns");return returnValue;    }@Override    public void add(int index, E element)    {taken = System.nanoTime();list.add(index,element);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".add(int,E) -> "+this.list.getClass().getName()+".add(int,E) times taken by "+taken+" ns");    }@Override    public E remove(int index)    {E returnValue;taken = System.nanoTime();returnValue = list.remove(index);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".remove(int) -> "+this.list.getClass().getName()+".remove(int) times taken by "+taken+" ns");return returnValue;    }@Override    public int indexOf(Object o)    {int returnValue;taken = System.nanoTime();returnValue = list.indexOf(o);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".indexOf(Object) -> "+this.list.getClass().getName()+".indexOf(Object) times taken by "+taken+" ns");return returnValue;    }@Override    public int lastIndexOf(Object o)    {int returnValue;taken = System.nanoTime();returnValue = list.lastIndexOf(o);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".lastIndexOf(Object) -> "+this.list.getClass().getName()+".lastIndexOf(Object) times taken by "+taken+" ns");return returnValue;    }@Override    public ListIterator<E> listIterator()    {ListIterator<E> returnValue;taken = System.nanoTime();returnValue = list.listIterator();taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".listIterator() -> "+this.list.getClass().getName()+".listIterator() times taken by "+taken+" ns");return returnValue;    }@Override    public ListIterator<E> listIterator(int index)    {ListIterator<E> returnValue;taken = System.nanoTime();returnValue = list.listIterator(index);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".listIterator(int) -> "+this.list.getClass().getName()+".listIterator(int) times taken by "+taken+" ns");return returnValue;    }@Override    public List<E> subList(int fromIndex, int toIndex)    {List<E> returnValue;taken = System.nanoTime();returnValue = list.subList(fromIndex,toIndex);taken = System.nanoTime()- taken;System.out.println(getClass().getName()+".subList(int,int) -> "+this.list.getClass().getName()+".subList(int,int) times taken by "+taken+" ns");return returnValue;    }}