HashMap vs FastHashMap
Test Code:
01 import java.util.HashMap;
02 import java.util.Map;
03
04 import org.apache.commons.collections.FastHashMap;
05
06 /**
07 * <p>HashMapTester.java</p>
08 *
09 * <p>
10 * <a href="HashMapTester.java.html"><i>View Source</i></a>
11 * </p>
12 *
13 * @author $Author$
14 * @version $Reversion$ $Date$
15 */
16 public class HashMapTester {
17
18 /**
19 *
20 */
21 public HashMapTester() {
22 super();
23 }
24
25 public static void main(String[] args){
26 int N = 50000;
27 long start = System.currentTimeMillis();
28 Map hm = new HashMap(N);
29 for(int i = 0; i < N ; i++){
30 hm.put(new Long(i),"HashMap " + i);
31 }
32 long end = System.currentTimeMillis() - start;
33 System.out.println("HashMap put " + N + " Object using" + (end/1000.0) + "s");
34 start = System.currentTimeMillis();
35 FastHashMap fhm = new FastHashMap(N);
36 //fhm.setFast(false);
37 for(int i = 0; i < N ; i++){
38 fhm.put(new Long(i),"FastHashMap " + i);
39 }
40 end = System.currentTimeMillis() - start;
41 System.out.println("FastHashMap put " + N + " Object using" + (end/1000.0) + "s");
42
43
44 start = System.currentTimeMillis();
45 for(int i = 0; i < N ; i++){
46 hm.get(new Long(i));
47 }
48 end = System.currentTimeMillis() - start;
49 System.out.println("HashMap get " + N + " Object using" + (end/1000.0) + "s");
50 fhm.setFast(true);
51 start = System.currentTimeMillis();
52 for(int i = 0; i < N ; i++){
53 fhm.get(new Long(i));
54 }
55 end = System.currentTimeMillis() - start;
56 System.out.println("FastHashMap get " + N + " Object using" + (end/1000.0) + "s");
57
58 }
59
60 }
Result:
HashMap put 50000 Object using1.021s
FastHashMap put 50000 Object using1.221s
HashMap get 50000 Object using0.561s
FastHashMap get 50000 Object using0.04s