Java讀寫Properties文件

Java中讀寫資源文件最重要的類是Properties,功能大致如下：
1. 讀寫Properties文件
2. 讀寫XML文件
3. 不僅可以讀寫上述兩類文件，還可以讀寫其它格式文件如txt等，只要符合key=value格式即可.

注意：資源文件中含有中文時的處理方法
1. 將中文字符通過工作轉成utf8編碼，可以通過Java自帶的nativetoascii或Eclipse中的屬性編輯器。
2. 直接調用 new String(youChineseString.getBytes("ISO-8859-1"), "GBK");

附：WEB程序中加載資源文件的方法
Properties prop = null;
1. prop = Thread.currentThread().getContextClassLoader().getResourceAsStream("filename");
2. prop = this.getClass().getClassLoader().getResourceAsStream("filename");

Properties能讀取以key,value存儲的任何格式文件，究竟有什麼神奇，貓一眼類結構，

原來它繼承了Hashtable並實現了Map接口,這樣大家放心了吧。

print?

1. package apistudy;
3. import java.io.File;
4. import java.io.FileInputStream;
5. import java.io.FileOutputStream;
6. import java.io.IOException;
7. import java.io.InputStream;
8. import java.io.OutputStream;
9. import java.io.UnsupportedEncodingException;
10. import java.util.Properties;
12. public class PropertiesTest
13. {
15. public static void main(String[] args)
16. {
18. String readfile = "d:" + File.separator + "readfile.properties";
19. String writefile = "d:" + File.separator + "writefile.properties";
20. String readxmlfile = "d:" + File.separator + "readxmlfile.xml";
21. String writexmlfile = "d:" + File.separator + "writexmlfile.xml";
22. String readtxtfile = "d:" + File.separator + "readtxtfile.txt";
23. String writetxtfile = "d:" + File.separator + "writetxtfile.txt";
25. readPropertiesFile(readfile); //讀取properties文件
26. writePropertiesFile(writefile); //寫properties文件
27. readPropertiesFileFromXML(readxmlfile); //讀取XML文件
28. writePropertiesFileToXML(writexmlfile); //寫XML文件
29. readPropertiesFile(readtxtfile); //讀取txt文件
30. writePropertiesFile(writetxtfile); //寫txt文件
31. }
33. //讀取資源文件,並處理中文亂碼
34. public static void readPropertiesFile(String filename)
35. {
36. Properties properties = new Properties();
37. try
38. {
39. InputStream inputStream = new FileInputStream(filename);
40. properties.load(inputStream);
41. inputStream.close(); //關閉流
42. }
43. catch (IOException e)
44. {
45. e.printStackTrace();
46. }
47. String username = properties.getProperty("username");
48. String passsword = properties.getProperty("password");
49. String chinese = properties.getProperty("chinese");
50. try
51. {
52. chinese = new String(chinese.getBytes("ISO-8859-1"), "GBK"); // 處理中文亂碼
53. }
54. catch (UnsupportedEncodingException e)
55. {
56. e.printStackTrace();
57. }
58. System.out.println(username);
59. System.out.println(passsword);
60. System.out.println(chinese);
61. }
63. //讀取XML文件,並處理中文亂碼
64. public static void readPropertiesFileFromXML(String filename)
65. {
66. Properties properties = new Properties();
67. try
68. {
69. InputStream inputStream = new FileInputStream(filename);
70. properties.loadFromXML(inputStream);
71. inputStream.close();
72. }
73. catch (IOException e)
74. {
75. e.printStackTrace();
76. }
77. String username = properties.getProperty("username");
78. String passsword = properties.getProperty("password");
79. String chinese = properties.getProperty("chinese"); //XML中的中文不用處理亂碼，正常顯示
80. System.out.println(username);
81. System.out.println(passsword);
82. System.out.println(chinese);
83. }
85. //寫資源文件，含中文
86. public static void writePropertiesFile(String filename)
87. {
88. Properties properties = new Properties();
89. try
90. {
91. OutputStream outputStream = new FileOutputStream(filename);
92. properties.setProperty("username", "myname");
93. properties.setProperty("password", "mypassword");
94. properties.setProperty("chinese", "中文");
95. properties.store(outputStream, "author: [email protected]");
96. outputStream.close();
97. }
98. catch (IOException e)
99. {
100. e.printStackTrace();
101. }
102. }
104. //寫資源文件到XML文件，含中文
105. public static void writePropertiesFileToXML(String filename)
106. {
107. Properties properties = new Properties();
108. try
109. {
110. OutputStream outputStream = new FileOutputStream(filename);
111. properties.setProperty("username", "myname");
112. properties.setProperty("password", "mypassword");
113. properties.setProperty("chinese", "中文");
114. properties.storeToXML(outputStream, "author: [email protected]");
115. outputStream.close();
116. }
117. catch (IOException e)
118. {
119. e.printStackTrace();
120. }
121. }
123. }