测试ArrayList和LinkedList性能

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测试ArrayList和LinkedList性能的案例

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import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.Random;
/**
 * Created by gene on 2017/4/23.
 */
public class Test {
    public static void main(String[] args) {
        ArrayList arraylist = new ArrayList();
        ArrayList bigarraylist = new ArrayList(5000000);
        LinkedList linkedlist = new LinkedList();
        Object obj = new Object();
        /**
         * 测试ArrayList和LinkedList在末尾插入的性能
         */
        long start = System.currentTimeMillis();
        for (int i = 0; i < 5000000; i++) {
            arraylist.add(obj);
        }
        long end = System.currentTimeMillis();
        System.out.println("ArrayList插入用时：" + (end - start));
        start=System.currentTimeMillis();
        for (int i = 0; i < 5000000; i++) {
            linkedlist.add(obj);
        }
        end = System.currentTimeMillis();
        System.out.println("LinkedList插入用时：" + (end - start));
        start = System.currentTimeMillis();
        for (int i = 0; i < 5000000; i++) {
            bigarraylist.add(obj);
        }
        end = System.currentTimeMillis();
        System.out.println("调整初始容量的arrayList插入用时：" + (end - start));
        /**
         * 测试ArrayList和LinkedList随机插入的性能
         */
        Random r1 = new Random();
        Random r2 = new Random();
        start = System.currentTimeMillis();
        for (int i = 0; i < 1000; i++) {
            arraylist.add(r1.nextInt(1000), obj);
        }
        end = System.currentTimeMillis();
        System.out.println("ArrayList随机插入用时：" + (end - start));
        LinkedHashMap map = new LinkedHashMap();
        map.put(1, 1);
        map.put(2, 2);
        start = System.currentTimeMillis();
        for (int i = 0; i < 1000; i++) {
            linkedlist.add(r2.nextInt(1000), obj);
        }
        end = System.currentTimeMillis();
        System.out.println("LinkedList随机插入用时：" + (end - start));
        /**
         * 测试ArrayList和LinkedList的删除性能
         */
        start = System.currentTimeMillis();
        for (int i = 0; i < 100; i++) {
            arraylist.remove(250000);
        }
        end = System.currentTimeMillis();
        System.out.println("ArrayList删除用时：" + (end - start));
        start = System.currentTimeMillis();
        for (int i = 0; i < 100; i++) {
            linkedlist.remove(250000);
        }
        end = System.currentTimeMillis();
        System.out.println("LinkedList删除用时：" + (end - start));
    }
}