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标题: 一个操作Properties的实用类。。 [打印本页]

作者: chenyajun5 时间: 2005-02-19 09:25
标题: 一个操作Properties的实用类。。
一个操作Properties的实用类。。
import java.io.*;
import java.net.*;
import java.util.*;
public class PropMan
{
private File propertiesFile;
private static Map propetyManager = new HashMap();
private static Object managerLock = new Object();
private PropMan(String filename)
{
      propertiesFile = null;
      setPropertyFile(filename);
}
public static PropMan getInstance(String propertyFileName)
{
      return new PropMan(propertyFileName);
}
public void setPropertyFile(String filename)
{
      try
      {
         propertiesFile = new File((new URI(getClass().getResource(filename).getPath())).getPath());
      }
      catch(URISyntaxException e)
      {
         System.out.println("error");
      }
}
private void loadProps(Properties prop)       throws UtilException
{
      if(prop != null)
         prop.clear();
      InputStream in = null;
      try
      {
         in = new FileInputStream(propertiesFile);
         prop.load(in);
      }
      catch(Exception e)
      {
         String error = "Error reading the properties file: " + propertiesFile + " in PropMan.loadProps()n" + e;
         throw new UtilException(error);
      }
      finally
      {
         try
         {
            in.close();
         }
         catch(Exception e) { }
      }
      return;
}
private Properties getProperties()       throws UtilException
{
      Properties prop = (Properties)propetyManager.get(propertiesFile);
      if(prop == null)
         synchronized(managerLock)
         {
            if(prop == null)
            {
                  prop = new Properties();
                  loadProps(prop);
            }
         }
      return prop;
}
public String getProperty(String name)
{
      return getProperty(name, null);
}
public String getProperty(String name, String defaultString)
{
      try
      {
         return getProperties().getProperty(name);
      }
      catch(Exception e)
      {
      }
      return defaultString;
}
public void setProperty(String name, String value)
{
      Properties prop = null;
      try
      {
         prop = getProperties();
         if(prop == null)
            prop = new Properties();
      }
      catch(Exception e)
      {
         prop = new Properties();
      }
      prop.setProperty(name, value);
      propetyManager.put(propertiesFile, prop);
}
public void deleteProperty(String name)
{
      try
      {
         Properties prop = getProperties();
         prop.remove(name);
         propetyManager.put(propertiesFile, prop);
      }
      catch(Exception e)
      {
      }
}
public void saveProperty()       throws UtilException
{
      OutputStream out = null;
      try
      {
         if(!propertiesFile.exists())
            propertiesFile.createNewFile();
         out = new FileOutputStream(propertiesFile);
         ((Properties)propetyManager.get(propertiesFile)).store(out, propertiesFile.getPath());
      }
      catch(Exception ioe)
      {
         String errorMessage = "There was an error writing properties to " + propertiesFile + ". " ;
         throw new UtilException(errorMessage, ioe);
      }
      finally
      {
         try
         {
            out.close();
         }
         catch(Exception e) { }
      }
      return;
}
public void putProperty(String name, String value)
{
      Properties prop = null;
      try
      {
         prop = getProperties();
         if(prop == null)
            prop = new Properties();
      }
      catch(Exception e)
      {
         prop = new Properties();
      }
      prop.put(name, value);
      propetyManager.put(propertiesFile, prop);
}
public Enumeration propertyNames()
{
      try
      {
         return getProperties().propertyNames();
      }
      catch(UtilException e)
      {
         return ((Properties)propetyManager.get(propertiesFile)).propertyNames();
      }
}
public boolean propertyFileIsReadable()
{
      try
      {
         return propertiesFile.canRead();
      }
      catch(Exception e)
      {
         return false;
      }
}
public boolean propertyFileIsWritable()
{
      return propertiesFile.isFile() && propertiesFile.canWrite();
}
public boolean propertyFileExists()
{
      return propertiesFile.exists() && propertiesFile.isFile();
}
public void reloadProps()       throws UtilException
{
      loadProps(getProperties());
}
}

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