fileresolverimpl.java

java1.6众多例子参考

/*
 * @(#)FileResolverImpl.java	1.4 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.corba.se.impl.resolver ;

import org.omg.CORBA.ORBPackage.InvalidName;

import com.sun.corba.se.spi.resolver.Resolver ;

import java.util.Enumeration;
import java.util.Properties;
import java.util.Set;
import java.util.HashSet;

import java.io.File;
import java.io.FileInputStream;

import com.sun.corba.se.spi.orb.ORB ;

import com.sun.corba.se.impl.orbutil.CorbaResourceUtil ;

public class FileResolverImpl implements Resolver
{
    private ORB orb ;
    private File file ;
    private Properties savedProps ;
    private long fileModified = 0 ;

    public FileResolverImpl( ORB orb, File file )
    {
	this.orb = orb ;
	this.file = file ;
	savedProps = new Properties() ;
    }

    public org.omg.CORBA.Object resolve( String name ) 
    {
	check() ;
	String stringifiedObject = savedProps.getProperty( name ) ;
	if (stringifiedObject == null) {
	    return null;
	}
	return orb.string_to_object( stringifiedObject ) ;
    }

    public java.util.Set list() 
    {
	check() ;

	Set result = new HashSet() ;

	// Obtain all the keys from the property object
	Enumeration theKeys = savedProps.propertyNames();
	while (theKeys.hasMoreElements()) {
	    result.add( theKeys.nextElement() ) ;
	}

	return result ;
    }

    /**
    * Checks the lastModified() timestamp of the file and optionally
    * re-reads the Properties object from the file if newer.
    */
    private void check() 
    {
	if (file == null)
	    return;

	long lastMod = file.lastModified();
	if (lastMod > fileModified) {
	    try {
		FileInputStream fileIS = new FileInputStream(file);
		savedProps.clear();
		savedProps.load(fileIS);
		fileIS.close();
		fileModified = lastMod;
	    } catch (java.io.FileNotFoundException e) {
		System.err.println( CorbaResourceUtil.getText(
		    "bootstrap.filenotfound", file.getAbsolutePath()));
	    } catch (java.io.IOException e) {
		System.err.println( CorbaResourceUtil.getText(
		    "bootstrap.exception",
		    file.getAbsolutePath(), e.toString()));
	    }
	}
    }
}