JAVA读取PROPERTIES文件方式一

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStream;
 4 import java.io.InputStreamReader;
 5 import java.util.Properties;
 6 
 7 import org.apache.commons.logging.Log;
 8 import org.apache.commons.logging.LogFactory;
 9 
10 /**
11  * 配置文件读取工具
12  */
13 public class ConfigurableConstants
14 {
15 
16     protected static final String PROPERTIES_PATH = "config.properties";
17 
18     protected static Log logger = LogFactory.getLog(ConfigurableConstants.class);
19     protected static Properties p = new Properties();
20     static
21     {
22         init(PROPERTIES_PATH);
23     }
24 
25     /**
26      * 静态读入属性文件到Properties p变量中
27      */
28     protected static void init(String propertyFileName)
29     {
30         InputStream in =  null;
31         try
32         {
33             // class.getClassLoader()获得该class文件加载的web应用的目录，如WEB-INF/classes/就是根目录
34             // getResourceAsStream(relativeFilePath):定位该文件且获得它的输出流
35             in = ConfigurableConstants.class.getClassLoader().getResourceAsStream(propertyFileName);
36             BufferedReader bf = null;
37             if (in != null)
38                 // load输出流到Properties对象中
39                 // 因为字节流是无法读取中文的，所以采取reader把inputStream转换成reader用字符流来读取中文。
40                 bf = new BufferedReader(new InputStreamReader(in));
41             p.load(bf);
42         }
43         catch (IOException e)
44         {
45             logger.error("load " + propertyFileName + " into Constants error!");
46         }
47         finally
48         {
49             if (in != null)
50             {
51                 try
52                 {
53                     in.close();
54                 }
55                 catch (IOException e)
56                 {
57                     logger.error("close " + propertyFileName + " error!");
58                 }
59             }
60         }
61     }
62 
63     /**
64      * 封装了Properties类的getProperty函数,使p变量对子类透明.
65      *
66      * @param key
67      *            property key.
68      * @param defaultValue
69      *            当使用property key在properties中取不到值时的默认值.
70      */
71     public static String getProperty(String key, String defaultValue)
72     {
73         return p.getProperty(key, defaultValue).trim();
74     }
75 
76 }