JDK 1.5中泛型(Generics type)的性能测试再测试

import java.util.ArrayList;
import java.util.List;

/**
* @author yoti
* 在JDK 1.5下
*/

public class PerformanceTest {

/** Creates a new instance of PerformanceTest */

public PerformanceTest() {}

public static void main(String[] args) {
long[] beforeAdd = new long[2];
long[] afterAdd = new long[2];
long[] beforeGet = new long[2];
long[] afterGet = new long[2];
double[] sumAdd = new double[2];
double[] sumGet = new double[2];
int oneOrTwo = 0;

System.out.println(
"java.version=" + System.getProperty("java.version"));
for (int k = 0; k < 100; k++) {
if ((k % 2) == 0) {
List list = new ArrayList();
beforeAdd[0] = System.currentTimeMillis();
int end = 100000;
for (int i = 0; i < end; i++) {
list.add(new Integer(i));
}

afterAdd[0] = System.currentTimeMillis();

beforeGet[0] = System.currentTimeMillis();
for (int j = 0; j < end; j++) {
Integer integer = (Integer) list.get(j);
}

afterGet[0] = System.currentTimeMillis();
} else {
List<Integer> list = new ArrayList<Integer>();
beforeAdd[1] = System.currentTimeMillis();
int end = 100000;
for (int i = 0; i < end; i++) {
list.add(new Integer(i));
}

afterAdd[1] = System.currentTimeMillis();

beforeGet[1] = System.currentTimeMillis();
for (int j = 0; j < end; j++) {
Integer integer = (Integer) list.get(j);
}

afterGet[1] = System.currentTimeMillis();
}
oneOrTwo = k % 2;
double addTime = (afterAdd[oneOrTwo] - beforeAdd[oneOrTwo]) / 1000.0d;
double getTime = (afterGet[oneOrTwo] - beforeGet[oneOrTwo]) / 1000.0d;
sumAdd[oneOrTwo] += addTime;
sumGet[oneOrTwo] += getTime;
}
System.out.println("不使用generics时Add总耗时：" + sumAdd[0]);
System.out.println("使用generics后Add总耗时：" + sumAdd[1]);
System.out.println("不使用generics时Get总耗时：" + sumGet[0]);
System.out.println("使用generics后Get总耗时：" + sumGet[1]);
}
}

java.version=1.5.0
不使用generics时Add总耗时：12.318
使用generics后Add总耗时：12.658
不使用generics时Get总耗时：0.40100000000000025
使用generics后Get总耗时：0.4200000000000002

//另一次测试
java.version=1.5.0
不使用generics时Add总耗时：13.358999999999993
使用generics后Add总耗时：13.127999999999998
不使用generics时Get总耗时：0.5120000000000002
使用generics后Get总耗时：0.3900000000000001