map性能测试

Test.java

package one;

import java.util.*;

/**
 * http://baike.xsoftlab.net/view/250.html
 * Size:100 * 10000 循环11次  去掉第一次测试数据

 */
public class Test {
    static int hashMapW = 0;
    static int hashMapR = 0;
    static int linkMapW = 0;
    static int linkMapR = 0;
    static int treeMapW = 0;
    static int treeMapR = 0;
    static int hashTableW = 0;
    static int hashTableR = 0;
 
    public static void main(String[] args) {
        for (int i = 0; i < 11; i++) {
            Test test = new Test();
            test.test(100 * 10000);
            System.out.println();
        }
 
        System.out.println("hashMapW = " + hashMapW / 10);
        System.out.println("hashMapR = " + hashMapR / 10);
        System.out.println("linkMapW = " + linkMapW / 10);
        System.out.println("linkMapR = " + linkMapR / 10);
        System.out.println("treeMapW = " + treeMapW / 10);
        System.out.println("treeMapR = " + treeMapR / 10);
        System.out.println("hashTableW = " + hashTableW / 10);
        System.out.println("hashTableR = " + hashTableR / 10);
    }
 
    public void test(int size) {
        int index;
        Random random = new Random();
        String[] key = new String[size];

        // HashMap 插入
        Map<String, String> map = new HashMap<String, String>();
        long start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            key[i] = UUID.randomUUID().toString();
            map.put(key[i], UUID.randomUUID().toString());
        }
        long end = System.currentTimeMillis();

        if (hashMapW==0)
            hashMapW=1;
        else
            hashMapW += (end - start);

        System.out.println("HashMap插入耗时 = " + (end - start) + " ms");

        // HashMap 读取
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            index = random.nextInt(size);
            map.get(key[index]);
        }
        end = System.currentTimeMillis();

        if (hashMapR==0)
            hashMapR=1;
       else
           hashMapR += (end - start);

        System.out.println("HashMap读取耗时 = " + (end - start) + " ms");

        // LinkedHashMap 插入
        map = new LinkedHashMap<String, String>();
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            key[i] = UUID.randomUUID().toString();
            map.put(key[i], UUID.randomUUID().toString());
        }
        end = System.currentTimeMillis();

        if (linkMapW==0)
            linkMapW=1;
      else
          linkMapW += (end - start);

        System.out.println("LinkedHashMap插入耗时 = " + (end - start) + " ms");

        // LinkedHashMap 读取
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            index = random.nextInt(size);
            map.get(key[index]);
        }
        end = System.currentTimeMillis();

        if (linkMapR==0)
            linkMapR=1;
       else
           linkMapR += (end - start);

        System.out.println("LinkedHashMap读取耗时 = " + (end - start) + " ms");

        // TreeMap 插入
        key = new String[size];
        map = new TreeMap<String, String>();
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            key[i] = UUID.randomUUID().toString();
            map.put(key[i], UUID.randomUUID().toString());
        }
        end = System.currentTimeMillis();

        if (treeMapW==0)
            treeMapW=1;
       else
           treeMapW += (end - start);

        System.out.println("TreeMap插入耗时 = " + (end - start) + " ms");

        // TreeMap 读取
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            index = random.nextInt(size);
            map.get(key[index]);
        }
        end = System.currentTimeMillis();

        if (treeMapR==0)
            treeMapR=1;
       else
           treeMapR += (end - start);

        System.out.println("TreeMap读取耗时 = " + (end - start) + " ms");

        // Hashtable 插入
        key = new String[size];
        map = new Hashtable<String, String>();
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            key[i] = UUID.randomUUID().toString();
            map.put(key[i], UUID.randomUUID().toString());
        }
        end = System.currentTimeMillis();

        if (hashTableW==0)
            hashTableW=1;
       else
           hashTableW += (end - start);

        System.out.println("Hashtable插入耗时 = " + (end - start) + " ms");

        // Hashtable 读取
        start = System.currentTimeMillis();
        for (int i = 0; i < size; i++) {
            index = random.nextInt(size);
            map.get(key[index]);
        }
        end = System.currentTimeMillis();

        if (hashTableR==0)
            hashTableR=1;
       else
           hashTableR += (end - start);

        System.out.println("Hashtable读取耗时 = " + (end - start) + " ms");
    }
}