Multiple replacements from an input file with 1.4 Regex

Question

hi,
i'm trying to make multiple replacments to a source file <source> using a second input file <patterns> to hold the regex's. the problem i'm having is that the output file only makes the last replacement listed in the input file. Example if the input file is
a#123
b#456
only b is changed to 456 and a remains.
the second debug i've got shows that all the replacements are in memory, but i'm not sure how to write them all to the file.
the syntax is Java MyPatternMatcher <source> <patterns>
import java.util.regex.*;
import java.io.*;
import java.util.*;
public class MyPatternResolver {
     private File patternFile;
     private File sourceFile;
     private Vector patterns = new Vector();
     public MyPatternResolver(String sourceFile, String patternFile) {
          this.sourceFile = new File(sourceFile);
          this.patternFile = new File(patternFile);
          loadPatterns();
          resolve();
     private void loadPatterns() {
          // read in each line if File
          FileReader fileReader = null;
          try {
               fileReader = new FileReader(patternFile);
          } catch(FileNotFoundException fnfe) {
               fnfe.printStackTrace();
          BufferedReader reader = new BufferedReader(fileReader);
          String s = null;
          String[] strArr = new String[2];
          try {
               while((s = reader.readLine()) != null) {
                    StringTokenizer tokenizer = new StringTokenizer(s, "#");
                    for (int i =0; i < 2; i++) {
                         strArr[i] = tokenizer.nextToken();
                         //Debugging Info
                         System.out.println("Token Value " + i + " = " + strArr);
                         //End Debugging Info
                    patterns.add(new PatternResolver(strArr[0], strArr[1], sourceFile));
          } catch(IOException ioe) {
                    ioe.printStackTrace();
     private void resolve() {
          Iterator iterator = patterns.iterator();
          while(iterator.hasNext()) {
               PatternResolver pr = (PatternResolver) iterator.next();
               pr.resolve();
     public static void main(String[] args) {
          MyPatternResolver mpr = new MyPatternResolver(args[0], args[1]);
     public class PatternResolver {
          private String match, replace;
          private File source;
     public PatternResolver(String s1, String s2, File f) {
          this.match = s1;
          this.replace = s2;
          this.source = f;
     public File resolve() {
          File fout = null;
          try {
     //Create a file object with the file name in the argument:
     fout = new File(sourceFile.getName() + "_");
     //Open and input and output stream
     FileInputStream fis = new FileInputStream(sourceFile);
     FileOutputStream fos = new FileOutputStream(fout);
     BufferedReader in = new BufferedReader(new InputStreamReader(fis));
     BufferedWriter out = new BufferedWriter(new OutputStreamWriter(fos));
     // The find and replace statements
     Pattern p = Pattern.compile(match);
               Matcher m = p.matcher(replace);
               //Debugging Info
               System.out.println("Match value = " + match + " Replace value = " + replace);
               //Debugging Complete
               String aLine = null;
               while((aLine = in.readLine()) != null) {
               m.reset(aLine);
               //Make replacements
               String result = m.replaceAll(replace);
               out.write(result);
          out.newLine();
               in.close();
               out.close();
          } catch (Exception e) {
               e.printStackTrace();
return fout;

Answer 1

If your aim is to learn about regex, then its okay.
Otherwise you might want to check the utility "sed" (stream editor) which does something similar what you are up to. It is a POSIX (.i.e. UNIX) utility, but it is available (in several versions) for other platforms (including Windows) too. (Cf. Cygnus or Mingw).