/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements.  See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License.  You may obtain a copy of the License at *  *      http://www.apache.org/licenses/LICENSE-2.0 *  * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.log4j.performance;import java.util.Vector;/**   Compares the performance of looping through a list versus a Vector.   Chain looping is *20* times faster than vector access on JDK 1.1.7B on NT*/public class ListVsVector {  static int RUN_LENGTH = 1000000;  static Vector v = new Vector();  static Chain head;  static String tmp;  static  public   void main(String[] args) {    v.addElement("aaa");    v.addElement("bbb");    v.addElement("ccc");    v.addElement("ddd");    v.addElement("eee");        Chain c = new Chain("aaa");    head = c;    c.next = new Chain("bbb"); c = c.next;    c.next = new Chain("ccc"); c = c.next;    c.next = new Chain("ddd"); c = c.next;    c.next = new Chain("eee");    double t;    t = loopChain();    System.out.println("Looping thourgh the chain took " + t);    t = loopVector();    System.out.println("Looping thourgh the vector took " + t);  }  static  double loopChain() {    long before = System.currentTimeMillis();    Chain c;    for(int i = 0; i < RUN_LENGTH; i++) {      c = head;      while(c != null) {	tmp = c.s;	c = c.next;      }    }    return (System.currentTimeMillis() - before)*1000.0/RUN_LENGTH;      }  static  double loopVector() {    long before = System.currentTimeMillis();    int size = v.size();    for(int i = 0; i < RUN_LENGTH; i++) {      for(int j = 0; j < size; j++)	tmp = (String) v.elementAt(j);    }    return (System.currentTimeMillis() - before)*1000.0/RUN_LENGTH;      }  static class Chain {    public String s;    public Chain next;    Chain(String s) {      this.s = s;    }        void setNext(Chain c) {      next = c;    }  }}