array数组，arraylist,hashset,vector,linkedlist,速度对比。

话不多说,数组多是用在知道大小的时候，如果不知道大小，当然从arraylist hashset vector linkedlist中选择一个

 

 

结果让我也有些意外

所有查找都是for each的形式，如果用正常的循环，linkedList的性能就会差非常大，而arraylist就会非常的快ArrayList查找到99998，所消耗的时间：853毫秒

1. import java.util.ArrayList; 2. import java.util.Calendar; 3. import java.util.GregorianCalendar; 4. import java.util.HashSet; 5. import java.util.LinkedList; 6. import java.util.Vector; 7. public class TimeTest { 8. public static void main(String[] args) { 9. int[] a = new int[99999]; 10. ArrayList<Integer> b = new ArrayList<Integer>(); 11. HashSet<Integer> h = new HashSet<Integer>(); 12. Vector<Integer> v = new Vector<Integer>(); 13. LinkedList<Integer> l = new LinkedList<Integer>(); 14. long time1; 15. long time2; 16. Calendar c; 17. for (int i = 0; i < 99999; i++) { 18. a[i] = i; 19. b.add(i); 20. h.add(i); 21. v.add(i); 22. l.add(i); 23. } 24. 25. 26. 27. c = new GregorianCalendar(); 28. time1 = c.getTimeInMillis(); 29. for (int i = 0; i < 99999; i++) { 30. a[i] = i; 31. } 32. c = new GregorianCalendar(); 33. time2 = c.getTimeInMillis(); 34. System.out.println("数组插入到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 35. 36. c = new GregorianCalendar(); 37. time1 = c.getTimeInMillis(); 38. for (int i = 0; i < 999; i++) { 39. for (Integer num : a) { 40. if (num == 99998) { 41. break; 42. } 43. } 44. } 45. c = new GregorianCalendar(); 46. time2 = c.getTimeInMillis(); 47. System.out.println("数组查找到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 48. 49. c = new GregorianCalendar(); 50. time1 = c.getTimeInMillis(); 51. for (int i = 0; i < 99999; i++) { 52. b.add(i); 53. } 54. c = new GregorianCalendar(); 55. time2 = c.getTimeInMillis(); 56. System.out.println("ArrayList插入到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 57. 58. c = new GregorianCalendar(); 59. time1 = c.getTimeInMillis(); 60. for (int i = 0; i < 999; i++) { 61. for (Integer num : b) { 62. if (num == 99998) { 63. break; 64. } 65. } 66. } 67. c = new GregorianCalendar(); 68. time2 = c.getTimeInMillis(); 69. System.out 70. .println("ArrayList查找到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 71. c = new GregorianCalendar(); 72. time1 = c.getTimeInMillis(); 73. for (int i = 0; i < 99999; i++) { 74. h.add(i); 75. } 76. c = new GregorianCalendar(); 77. time2 = c.getTimeInMillis(); 78. System.out.println("HashSet插入到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 79. 80. c = new GregorianCalendar(); 81. time1 = c.getTimeInMillis(); 82. for (int i = 0; i < 999; i++) { 83. for (Integer num : h) { 84. if (num == 99998) { 85. break; 86. } 87. } 88. } 89. c = new GregorianCalendar(); 90. time2 = c.getTimeInMillis(); 91. System.out.println("HashSet查找到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 92. c = new GregorianCalendar(); 93. time1 = c.getTimeInMillis(); 94. for (int i = 0; i < 99999; i++) { 95. v.add(i); 96. } 97. c = new GregorianCalendar(); 98. time2 = c.getTimeInMillis(); 99. System.out.println("Vector插入到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 100. 101. c = new GregorianCalendar(); 102. time1 = c.getTimeInMillis(); 103. for (int i = 0; i < 999; i++) { 104. for (Integer num : v) { 105. if (num == 99998) { 106. break; 107. } 108. } 109. } 110. c = new GregorianCalendar(); 111. time2 = c.getTimeInMillis(); 112. System.out.println("Vector查找到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 113. 114. c = new GregorianCalendar(); 115. time1 = c.getTimeInMillis(); 116. for (int i = 0; i < 99999; i++) { 117. l.add(i); 118. } 119. c = new GregorianCalendar(); 120. time2 = c.getTimeInMillis(); 121. System.out.println("LinkedList插入到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 122. 123. c = new GregorianCalendar(); 124. time1 = c.getTimeInMillis(); 125. for (int i = 0; i < 999; i++) { 126. for (Integer num : l) { 127. if (num == 99998) { 128. break; 129. } 130. } 131. } 132. c = new GregorianCalendar(); 133. time2 = c.getTimeInMillis(); 134. System.out.println("LinkedList查找到99998，所消耗的时间：" + (time2 - time1) + "毫秒"); 135. } 136. }

 

数组插入到99998，所消耗的时间：1毫秒
数组查找到99998，所消耗的时间：813毫秒
ArrayList插入到99998，所消耗的时间：11毫秒
ArrayList查找到99998，所消耗的时间：3377毫秒
HashSet插入到99998，所消耗的时间：8毫秒
HashSet查找到99998，所消耗的时间：1745毫秒
Vector插入到99998，所消耗的时间：68毫秒
Vector查找到99998，所消耗的时间：9204毫秒
LinkedList插入到99998，所消耗的时间：14毫秒
LinkedList查找到99998，所消耗的时间：1594毫秒

竟然linkedlist是非常高速的数据结构，如果很计较插入速度arraylist最快，但是所消耗寻找时间也是最常

感谢http://blog.csdn.net/sharpyuce/archive/2007/11/07/1872114.aspx