ConfigFile.java

package greymerk.roguelike.config;


import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;


/**
 *	Provides configuration information from
 *	a file.
 */
public class ConfigFile extends ConfigurationProvider {


	private String filename;
	private ConfigurationParser parser;


	/**
	 *	Creates a configuration file by
	 *	parsing a certain file.
	 *
	 *	\param [in] filename
	 *		The name of the file to read.
	 *	\param [in] parser
	 *		A ConfigurationParser which will
	 *		be used to parse the data in
	 *		the given file.
	 */
	public ConfigFile (String filename, ConfigurationParser parser) throws Exception {
	
		this.filename=filename;
		this.parser=parser;
	
		//	Open a stream to the file-in-question
		FileInputStream stream;
		try {
		
			stream=new FileInputStream(filename);
		
		} catch (Exception e) {
		
			//	If the file could not be opened,
			//	we just create an empty set of
			//	configurations
			return;
		
		}
	
		//	Create an input stream reader
		//	to read from the specified file
		//	stream
		BufferedReader reader=new BufferedReader(
			new InputStreamReader(stream)
		);
		
		//	Loop until all settings have
		//	been extracted
		for (;;) {
		
			//	Attempt to extract setting
			Configuration config=parser.Parse(reader);
			
			//	If setting could not be extracted,
			//	the file is done, break
			if (config==null) break;
			
			//	We extracted a setting, insert it
			//	into the hash map
			kvp.put(
				config.Key,
				config.Value
			);
		
		}
	
	}
	
	
	/**
	 *	Writes configurations back to the file from
	 *	which they were originally drawn, according
	 *	to the strategy used to parse them.
	 */
	public void Write () throws Exception {
	
		ConfigFileWriter.Write(
			filename,
			this,
			parser
		);
	
	}


}