Regular Expression 正则表达式-2 (Java)

又用Java实现了一个，发现Java的正则表达式略有不同，而且也感觉到了Java的读写文件很不雅观。

/*
* Created on 2004-10-1
*/
import java.util.regex.*;
import java.io.*;

/**
* @author dancefire
*/
public class DataFilter {

public static void main(String[] args) {
if(args.length < 2)
{
System.err.println("Please enter 2 filenames(e.g. In.txt Out.txt)");
return;
}
String strIn = null, strOut = null;

// Get string from a file
strIn = readFile(args[0]);
// Process
strOut = filter(strIn);
// Store Result into a file
writeFile(args[1], strOut);

}
private static void writeFile(String filename, String data)
{
BufferedWriter wr = null;
try{
wr = new BufferedWriter( new FileWriter(filename));
wr.write(data);
}catch( Exception e )
{
e.printStackTrace();
}finally{
try{
if( wr != null )
wr.close();
}catch( Exception e ){
e.printStackTrace();
}
}
return;
}
private static String readFile(String filename)
{
String strRet = null;
BufferedReader rd = null;
try{
rd = new BufferedReader( new FileReader(filename));
String line = null;
StringBuffer sb = new StringBuffer();
while( (line=rd.readLine()) != null )
{
sb.append(line);
}
strRet = sb.toString();
}catch( Exception e )
{
e.printStackTrace();
}finally{
try{
if( rd != null )
rd.close();
}catch( Exception e ){
e.printStackTrace();
}
}
return strRet;
}
private static String filter(String input)
{
Pattern p = Pattern.compile("\"(\\w+):(\\w+)%(\\w+)\"");
Matcher m = p.matcher(input);
StringBuffer sb = new StringBuffer();
while(m.find())
{
sb.append( m.group(1) + ":" + m.group(2) + "*" + m.group(3) + "," + System.getProperty("line.separator") );
}
return sb.toString();
}
}