• import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  public class ArraysCompareCollectionsTest {
  public static void main(String[] args) {
  int count = 10000000;//通過改變循環次數來放大或放小結果
  System.out.println("Arrays‘s time is " + arraysTest(count));
  System.out.println("Collections‘s time is " + collectionsTest(count));
  }
  public static long arraysTest(int count) {
  long startTime = System.currentTimeMillis();
  for (int i = 0; i < count; i++) {
  List arrays = new ArrayList ();
  arrays.addAll(Arrays.asList("hello", "java", "world"));
  }
  return System.currentTimeMillis() - startTime;
  }public static long collectionsTest(int count) {
  long startTime = System.currentTimeMillis();
  for (int i = 0; i < count; i++) {
  List arrays = new ArrayList ();
  Collections.addAll(arrays,"hello", "java", "world");
  }
  return System.currentTimeMillis() - startTime;
  }
  }
  

  二、控制臺輸出結果分析

  
  

  1.當count=100000時,Collections的運行速度比Arrays的要快60ms左右

  
  

  2.當count=1000000時,Collections的運行速度比Arrays的要快100ms左右

  
  

  3.當count=10000000時,Collections的運行速度比Arrays的要快更多

持有對象---Arrays.asList()和Collections.addAll()的性能比較