最近在书上看到了说LinkedList和ArrayList 在这两种list中,前者插入和删除的效率要比后者高,于是我就写了个测试性能的小程序,可是结果总是相反的,插入相同的元素,ArrayList的时间消耗总是少的,不知道是不是这个测试小程序存在着缺点,希望高手指教,代码如下
package com.eric.collections; import java.util.ArrayList; import java.util.Collection; import java.util.LinkedList; import java.util.List; import java.util.Map; public class PrintlningContainers { static Collection <String>fill(Collection<String> collection) { collection.add(collection.getClass().getSimpleName()+":"); collection.add("ONE"); collection.add("TWO"); collection.add("THREE"); collection.add("FOUR"); return collection; } static Map<String,String> fill(Map<String, String> map) { map.put("rat", "Fuzzy"); map.put("cat", "Rags"); map.put("dog", "Bosco"); map.put("dog", "Spot"); return map; } static void insertEffective(List<Integer> list){ long begin=System.currentTimeMillis(); for (int i = 0; i < 5000000; i++) { list.add(i); } System.out.println(list.getClass().getSimpleName()+" add "+5000000+" elements spend time is: "+(System.currentTimeMillis()-begin)); } public static void main(String[] args) { // out.println(fill(new ArrayList<String>()));//存储的顺序就是插入的顺序 // out.println(fill(new LinkedList<String>()));//存储的顺序就是插入的顺序 // out.println(fill(new HashSet<String>()));//按照特殊的算法去存取 // out.println(fill(new TreeSet<String>()));//按照item的顺序就行存储 // out.println(fill(new LinkedHashSet<String>())); // out.println(fill(new HashMap<String, String>())); // out.println(fill(new TreeMap<String, String>())); // out.println(fill(new LinkedHashMap<String, String>())); insertEffective(new LinkedList<Integer>()); insertEffective(new ArrayList<Integer>()); } }