properties的应用

properties后缀的文件主要 功能为 键 值对&＃xff0c;根据键来获取相应的值。

以下是个小例子&＃xff1a; PropertiesUtils工具类

private static Properties docProps &＃61; null;

static {

  //获得properties文件的内容

   if(docProps &＃61;&＃61; null) {

       docProps &＃61; new Properties();

       docProps.load(PropertiesUtils.getResourceAsStream(properties文件路径));    

  }

}

  //通过路径获得资源

    public static InputStream getResourceAsStream( String resouce )
    {
        ClassLoader cl &＃61; PropertiesUtils.class.getClassLoader();
        if( cl!&＃61;null )
            return cl.getResourceAsStream( resouce );
        else
            return ClassLoader.getSystemResourceAsStream( resouce );
    }

 //通过传递进来的名字组装 键&＃xff0c;从properties中获取 对应值

   public static String getWordFileName(String configNum)
   {
       String returnVal &＃61; docProps.getProperty( "word." &＃43; configNum );
       if( returnVal &＃61;&＃61; null )
            return returnVal;
   }

  //调用getResourceAsStream方法 来最终获取到 资源文件的输入流

   public static InputStream getWordFile(String configNum) throws FileNotFoundException
  {
      try
      {
          String fileName &＃61; getWordFileName( configNum );
          return getResourceAsStream( Path.WORD &＃43; fileName );
      }
      catch (Exception e)
      {          

      }
      return null;
  }

 另外&＃xff0c;附上两个例子&＃xff1a;

1.  

"daoconfig.properties"文件 <br>UserDaoClass&＃61;com.jdbc.test.dao.impl.UserDaoImpl<br>Java代码 <br>public class DaoFactory { <br>private static UserDao userDao &＃61; null; <br>private static DaoFactory instance &＃61; new DaoFactory(); <br>private DaoFactory() { <br>try { <br>Properties prop &＃61; new Properties(); <br>//InputStream inStream &＃61; new FileInputStream(new File("src/daoconfig.properties")); <br>InputStream inStream &＃61; DaoFactory.class.getClassLoader() <br>.getResourceAsStream("daoconfig.properties"); <br>prop.load(inStream); <br>String userDaoClass &＃61; prop.getProperty("UserDaoClass"); <br>userDao &＃61; (UserDao) Class.forName(userDaoClass).newInstance(); <br>} catch (Exception e) { <br>throw new ExceptionInInitializerError(e); <br>} <br>} <br>public static DaoFactory getInstance() { <br>return instance; <br>} <br>public UserDao getUserDao() { <br>return userDao; <br>} <br>}

2.

package io;<br>import java.io.InputStream;<br>public class PropertiesUtil {<br>public static void main(String[] args) {<br>String path &＃61; "io/a.txt";<br>InputStream in &＃61; getResourceAsStream(path);<br>System.out.println(in);<br>}<br>private static InputStream getResourceAsStream(String path) {<br>InputStream in;<br>ClassLoader c1 &＃61; PropertiesUtil.class.getClassLoader();<br>if(c1 !&＃61; null) {<br>System.out.println("c1不是空的");<br>System.out.println(path);<br>in &＃61; c1.getResourceAsStream(path);<br>} else {<br>System.out.println("c1是空的");<br>in &＃61; ClassLoader.getSystemResourceAsStream(path);<br>}<br>return in;<br>}<br>}<br>

说明&＃xff1a;