Java中List效率的比较

package test;
import static java.lang.System.out;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Stack;
import java.util.Vector;
import java.util.concurrent.CopyOnWriteArrayList;
import org.apache.commons.collections.FastArrayList;
import org.apache.commons.collections.list.TreeList;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.StopWatch;
@SuppressWarnings("unchecked")
public class ListPerformance {
    public static void main(String[] args) {
        ListPerformance test = new ListPerformance(10 * 10000);
        out.print(StringUtils.center("Test List Performance: loop=" + test.loop, 80, ‘-‘));
        out.printf("/n%20s%10s%10s%10s%10s%10s%10s", "", "add", "insert", "remove", "get", "set",
                "iterator");
        test.benchmark(new FastArrayList());
        test.benchmark(new TreeList());
        test.benchmark(new ArrayList());
        test.benchmark(new LinkedList());
        test.benchmark(new CopyOnWriteArrayList());
        test.benchmark(new Vector());
        test.benchmark(new Stack());
        //2.测试排序
        out.print("/n/n");
        out.print(StringUtils.center("Test List sort Performance: loop=" + test.loop, 80, ‘-‘));
        out.printf("/n%20s%10s%10s%10s", "", "optimize", "worst", "random");
        test.benchmarkSort(new FastArrayList());
        test.benchmarkSort(new TreeList());
        test.benchmarkSort(new ArrayList());
        test.benchmarkSort(new LinkedList());
        //test.benchmarkSort(new CopyOnWriteArrayList());//UnsupportedOperationException
        test.benchmarkSort(new Vector());
        test.benchmarkSort(new Stack());
        //3.测试各种数据结构间转化
        out.print("/n/n");
        out.print(StringUtils.center("Test List convert Performance: loop=" + test.loop, 80, ‘-‘));
        out.printf("/n%20s%10s%10s%10s%10s%10s", "", "Tree", "Array", "Linked", "CopyOnWrite",
                "Vector");
        test.benchmarkConvert(new FastArrayList());
        test.benchmarkConvert(new TreeList());
        test.benchmarkConvert(new ArrayList());
        test.benchmarkConvert(new LinkedList());
        test.benchmarkConvert(new CopyOnWriteArrayList());
    }
    /**测试循环次数*/
    private int loop = 10000;
    public ListPerformance(int loop) {
        this.loop = loop;
    }
    public void benchmark(List list) {
        out.printf("/n%20s", list.getClass().getSimpleName());
        int j;
        StopWatch watch = null;
        //1.测试顺序性能(Add)
        (watch = new StopWatch()).start();
        for (int i = 0; i < loop; i++) {
            list.add(new Integer(i));
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
        //2.测试随机插入性能(Random insert)
        (watch = new StopWatch()).start();
        for (int i = 0; i < loop; i++) {
            j = (int) (Math.random() * loop);
            list.add(j, new Integer(-j));
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
        //3.测试随机索引删除(Random remove)
        (watch = new StopWatch()).start();
        for (int i = 0; i < loop; i++) {
            j = (int) (Math.random() * loop);
            list.remove(j);
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
        //4.测试随机取数性能(Random get)
        (watch = new StopWatch()).start();
        for (int i = 0; i < loop; i++) {
            j = (int) (Math.random() * loop);
            list.get(j);
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
        //5.测试随机更新性能(Random set)
        (watch = new StopWatch()).start();
        for (int i = 0; i < loop; i++) {
            j = (int) (Math.random() * loop);
            list.set(j, j);
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
        //6.测试迭代性能(Iterator)
        (watch = new StopWatch()).start();
        Iterator<Object> iter = list.iterator();
        while (iter.hasNext()) {
            iter.next();
        }
        watch.stop();
        out.printf("%10d", watch.getTime());
    }
    public void benchmarkConvert(List list) {
        out.printf("/n%20s", list.getClass().getSimpleName());
        StopWatch watch = null;
        //1.转TreeList
        (watch = new StopWatch()).start();
        new TreeList(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //2.转ArrayList
        (watch = new StopWatch()).start();
        new ArrayList(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //3.转LinkedList
        (watch = new StopWatch()).start();
        new LinkedList(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //4.转CopyOnWriteArrayList
        (watch = new StopWatch()).start();
        new CopyOnWriteArrayList(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //5.转Vector
        (watch = new StopWatch()).start();
        new Vector(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
    }
    public void benchmarkSort(List list) {
        out.printf("/n%20s", list.getClass().getSimpleName());
        StopWatch watch = null;
        //1.顺序List
        for (int i = 0; i < loop; i++) {
            list.add(new Integer(i));
        }
        (watch = new StopWatch()).start();
        Collections.sort(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //2.逆序List
        for (int i = loop - 1; i > 0; i--) {
            list.add(new Integer(i));
        }
        (watch = new StopWatch()).start();
        Collections.sort(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
        //3.随机顺序List
        for (int i = 0, j = 0; i < loop; i++) {
            j = (int) (Math.random() * loop);
            list.add(new Integer(j));
        }
        (watch = new StopWatch()).start();
        Collections.sort(list);
        watch.stop();
        out.printf("%10d", watch.getTime());
    }
}