在Java开发中,我们会使用到各种不同的库。在本文中,将给大家分享从从一万个开源的 Java 项目中提取出的前100个最常用的 Java 类,这些类有来自于 Java 的标准库,也有第三方库。每个类在同一个项目中只计数一次,下面的列表中显示前 100 名的类。
1. java.util.ArrayList (6958)
2. java.io.IOException (6866)
3.java.util.List (6784)
4. java.util.HashMap (5590)
5. java.util.Map (5413)
6. java.io.File (5097)
7. java.io.InputStream (4234)
8. java.util.Set (3915)
9. java.util.Arrays (3884)
10. java.util.Iterator (3856)
11. java.util.Collections (3643)
12. java.util.Date (3461)
13.java.util.HashSet (3278)
14. java.io.BufferedReader (3257)
15. java.util.Collection (3192)
16. java.net.URL (3168)
17. java.io.FileInputStream (3044)
18. java.io.InputStreamReader (3023)
19. org.junit.Test (3008)
20. java.io.FileOutputStream (2843)
21. java.io.FileNotFoundException (2669)
22. java.io.OutputStream (2563)
23. java.util.regex.Pattern (2469)
24. java.io.Serializable (2437)
25. java.util.LinkedList (2372)
26. java.text.SimpleDateFormat (2245)
27. java.util.Properties (2190)
28. java.util.Random (2171)
29. java.lang.reflect.Method (2141)
30. java.io.ByteArrayOutputStream (2112)
31. java.util.regex.Matcher (2012)
32. android.os.Bundle (2007)
33. java.util.logging.Logger (1999)
34.java.io.UnsupportedEncodingException (1968)
35. org.junit.Before (1920)
36. java.util.Comparator (1896)
37.java.io.ByteArrayInputStream (1868)
38. java.io.PrintWriter (1862)
39. java.util.Calendar (1854)
40. android.app.Activity (1843)
41. java.net.MalformedURLException (1828)
42. android.content.Context (1780)
43. android.view.View (1731)
44. java.util.Locale (1719)
45. java.util.Enumeration (1709)
46. java.util.Map.Entry (1705)
47. java.io.FileWriter (1677)
48. java.io.FileReader (1651)
49. android.util.Log (1614)
50. android.content.Intent (1601)
51. java.lang.reflect.Invocation Target Exception (1594)
52. java.util.logging.Level (1557)
53. java.lang.reflect.Field (1499)
54. java.io.StringWriter (1499)
55. android.widget.TextView (1442)
56. java.util.LinkedHashMap (1409)
57. java.io.Reader (1390)
58. java.net.URI (1377)
59. java.io.Writer (1339)
60. java.text.ParseException (1318)
61. junit.framework.TestCase (1318)
62. java.io.OutputStreamWriter (1295)
63. java.io.StringReader (1279)
64. java.io.BufferedWriter (1265)
65. java.util.Vector (1254)
66. java.util.StringTokenizer (1251)
67. java.text.DateFormat (1246)
68. java.util.concurrent.TimeUnit (1237)
69. java.io.BufferedInputStream (1235)
70. java.util.TreeMap (1227)
71. org.xml.sax.SAXException (1218)
72. javax.servlet.http.HttpServletRequest (1175)
73. java.io.PrintStream (1168)
74. java.util.TreeSet (1160)
75. android.widget.Toast (1157)
76. java.util.Hashtable (1154)
77. java.lang.reflect.Constructor (1139)
78. java.net.URLEncoder (1134)
79. java.security.NoSuch Algorithm Exception (1134)
80. org.w3c.dom.Document (1130)
81. android.widget.Button (1129)
82. org.junit.After (1128)
83. javax.servlet.http.HttpServletResponse (1109)
84. java.awt.Color (1099)
85. java.net.URISyntaxException (1085)
86. javax.servlet.ServletException (1081)
87. javax.xml.parsers.Document Builder Factory (1076)
88. java.lang.annotation.Retention (1075)
89. java.security.MessageDigest (1072)
90. java.util.concurrent.Executors (1062)
91. java.net.UnknownHostException (1057)
92. org.slf4j.Logger (1054)
93. java.sql.SQLException (1043)
94. org.slf4j.LoggerFactory (1042)
95. java.util.UUID (1040)
96. java.net.InetAddress (1026)
87. junit.framework.Assert (1011)
98. android.view.ViewGroup (1005)
99. java.util.concurrent.Concurrent HashMap (1001)
100. java.awt.event.ActionEvent (995)