properties类读取.properties 、简单XML文件、txt文件

Java中读写资源文件最重要的类是Properties,功能大致如下：

1. 读写Properties文件

2. 读写XML文件

3. 不仅可以读写上述两类文件，还可以读写其它格式文件如txt等，只要符合key=value格式即可.

注意：资源文件中含有中文时的处理方法

1. 将中文字符通过工作转成utf8编码，可以通过Java自带的nativetoascii或Eclipse中的属性编辑器。

2. 直接调用 new String(youChineseString.getBytes("ISO-8859-1"),"GBK");

附：WEB程序中加载资源文件的方法

Properties prop = null;

1. prop = Thread.currentThread().getContextClassLoader().getResourceAsstream("filename");

2. prop =this.getClass().getClassLoader().getResourceAsstream("filename");

Properties能读取以key,value存储的任何格式文件，究竟有什么神奇，猫一眼类结构，

原来它继承了Hashtable并实现了Map接口,这样大家放心了吧。

[java] view plain copy print ?

1. packageapistudy;
3. importjava.io.File;
4. importjava.io.FileInputStream;
5. importjava.io.FileOutputStream;
6. importjava.io.IOException;
7. importjava.io.InputStream;
8. importjava.io.OutputStream;
9. importjava.io.UnsupportedEncodingException;
10. importjava.util.Properties;
12. publicclassPropertiesTest
13. {
14. staticvoidmain(String[]args)
15. {
16. Stringreadfile="d:"+File.separator+"readfile.properties";
17. Stringwritefile="writefile.properties";
18. Stringreadxmlfile="readxmlfile.xml";
19. Stringwritexmlfile="writexmlfile.xml";
20. Stringreadtxtfile="readtxtfile.txt";
21. Stringwritetxtfile="writetxtfile.txt";
22. readPropertiesFile(readfile);//读取properties文件
23. writePropertiesFile(writefile);//写properties文件
24. readPropertiesFileFromXML(readxmlfile);//读取XML文件
25. writePropertiesFiletoXML(writexmlfile);//写XML文件
26. readPropertiesFile(readtxtfile);//读取txt文件
27. writePropertiesFile(writetxtfile);//写txt文件
28. }
29. //读取资源文件,并处理中文乱码
30. voidreadPropertiesFile(Stringfilename)
31. Propertiesproperties=newProperties();
32. try
33. InputStreaminputStream=newFileInputStream(filename);
34. properties.load(inputStream);
35. inputStream.close();//关闭流
36. }
37. catch(IOExceptione)
38. e.printstacktrace();
39. Stringusername=properties.getProperty("username");
40. Stringpasssword=properties.getProperty("password");
41. Stringchinese=properties.getProperty("chinese");
42. try
43. chinese=newString(chinese.getBytes("ISO-8859-1"),"GBK");//处理中文乱码
44. catch(UnsupportedEncodingExceptione)
45. e.printstacktrace();
46. System.out.println(username);
47. System.out.println(passsword);
48. System.out.println(chinese);
49. //读取XML文件,255); font-weight:bold; background-color:inherit">voidreadPropertiesFileFromXML(Stringfilename)
50. properties.loadFromXML(inputStream);
51. inputStream.close();
52. "chinese");//XML中的中文不用处理乱码，正常显示
53. //写资源文件，含中文
54. voidwritePropertiesFile(Stringfilename)
55. OutputStreamoutputStream=newFileOutputStream(filename);
56. properties.setProperty("username",0); background-color:inherit">"myname");
57. "password",0); background-color:inherit">"mypassword");
58. "chinese",0); background-color:inherit">"中文");
59. properties.store(outputStream,"author:[e-mail]");
60. outputStream.close();
61. catch(IOExceptione)
62. //写资源文件到XML文件，含中文
63. voidwritePropertiesFiletoXML(Stringfilename)
64. newProperties();
65. newFileOutputStream(filename);
66. "myname");
67. "mypassword");
68. "中文");
69. properties.storetoXML(outputStream,0); background-color:inherit">"author:[e-mail]");
70. outputStream.close();
71. }

运行本程序所需的资源文件，我是放在D盘根目录，如D:/readfile.properties

1. readfile.properties

username=myname

password=mypassword

chinese=中文

2.writefile.properties

#author: [e-mail]

#Fri May 28 22:19:44 CST 2010

chinese=/u4E2D/u6587

username=myname

3.readxmlfile.xml
<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<!DOCTYPE properties SYstem "http://java.sun.com/dtd/properties.dtd">

<properties>

<entry key="password">mypassword</entry>

<entry key="chinese">中文</entry>

<entry key="username">myname</entry>

</properties>

4.writexmlfile.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<comment>author: [e-mail]</comment>

</properties>

5. readtxtfile.txt

username=myname

password=mypassword

chinese=中文

6.writetxtfile.txt

#author: [e-mail]

#Fri May 28 22:25:16 CST 2010

password=mypassword

chinese=/u4E2D/u6587

username=myname