Use FileChannels and ByteBuffers to Store Patterns : Serialization « Regular Expressions « Java

Use FileChannels and ByteBuffers to Store Patterns

//Example File
#Email validator that adheres directly to the specification
#for email address naming. It allows for everything from
#ipaddress and country-code domains to very rare characters
#in the username.

#Matches UK postcodes according to the following rules 1. LN NLL
#eg N1 1AA 2. LLN NLL eg SW4 0QL 3. LNN NLL eg M23 4PJ 4. LLNN NLL
#eg WS14 0JT 5. LLNL NLL eg SW1N 4TB 6. LNL NLL eg W1C 8LQ Thanks
#to Simon Bell for informin ...
zip=^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$

#This regular expression matches dates of the form XX/XX/YYYY
#where XX can be 1 or 2 digits long and YYYY is always 4
#digits long.


import java.util.Properties;
import java.util.regex.*;
import java.util.*;
import java.nio.*;
import java.nio.channels.*;
import java.util.logging.Logger;

public class RegexProperties extends Properties {
  private static Logger log = Logger.getAnonymousLogger();

  public void load(String inStream) throws IOException,
      PatternSyntaxException {
    load(new FileInputStream(inStream));

  public void load(FileInputStream inStream) throws IOException,
      PatternSyntaxException {
    FileChannel fc = inStream.getChannel();

    ByteBuffer bb = ByteBuffer.allocate((int) fc.size());;
    String fileContent = new String(bb.array());

    Pattern pattern = Pattern.compile("^(.*)$", Pattern.MULTILINE);
    Matcher matcher = pattern.matcher(fileContent);

    while (matcher.find()) {
      String line =;
      if (line != null && !"".equals(line.trim())
          && !line.startsWith("#") && !line.startsWith("!")) {
        String keyValue[] = null;
        if (line.indexOf("=") > 0)
          keyValue = line.split("=", 2);
          keyValue = line.split(":", 2);

        if (keyValue != null) {
          super.put(keyValue[0].trim(), keyValue[1]);
    fc = null;
    bb = null;

  public void store(FileOutputStream out, String header)
      throws UnsupportedOperationException {
    throw new UnsupportedOperationException("unsupported for this class");

  public void putAll(Map t) {
    throw new UnsupportedOperationException("unsupported for this class");

Related examples in the same category

1.Using a Regular Expression to Filter Lines from a Reader
2.Reading Lines from a String Using a Regular Expression
3.Apply Regular Expressions on the contents of a file