JAVA读取PROPERTIES文件方式一

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.Properties;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;

 /**
  * 配置文件读取工具
  */
 public class ConfigurableConstants
 {

     protected static final String PROPERTIES_PATH = "config.properties";

     protected static Log logger = LogFactory.getLog(ConfigurableConstants.class);
     protected static Properties p = new Properties();
     static
     {
         init(PROPERTIES_PATH);
     }

     /**
      * 静态读入属性文件到Properties p变量中
      */
     protected static void init(String propertyFileName)
     {
         InputStream in =  null;
         try
         {
             // 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
             // getResourceAsStream(relativeFilePath):定位该文件且获得它的输出流
             in = ConfigurableConstants.class.getClassLoader().getResourceAsStream(propertyFileName);
             BufferedReader bf = null;
             if (in != null)
                 // load输出流到Properties对象中
                 // 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。
                 bf = new BufferedReader(new InputStreamReader(in));
             p.load(bf);
         }
         catch (IOException e)
         {
             logger.error("load " + propertyFileName + " into Constants error!");
         }
         finally
         {
             if (in != null)
             {
                 try
                 {
                     in.close();
                 }
                 catch (IOException e)
                 {
                     logger.error("close " + propertyFileName + " error!");
                 }
             }
         }
     }

     /**
      * 封装了Properties类的getProperty函数,使p变量对子类透明.
      *
      * @param key
      *            property key.
      * @param defaultValue
      *            当使用property key在properties中取不到值时的默认值.
      */
     public static String getProperty(String key, String defaultValue)
     {
         return p.getProperty(key, defaultValue).trim();
     }

 }