Comparable and Serializable interfaces

Question

Hi All,
I have developed a program in java which implements Comparable and Serializable Interfaces. After, I decided to run the program in J2ME. But later on, I found that MIDP doesn't implement these interfaces.
Some one can help me how to implement my own interfaces.
Thank you

Answer 1

Hi Supareno
I need urgently your help.
I developed Java program which works as predicitive text system for my mother tongue.I would like to move from Java to J2ME. But until now I have problems. please can u help me. the following code run in command line.
I tried to develop my own interfaces as you told me but it doesn't work.
Help me also for reading and writing text files.
Thank you
import java.util.*;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
public class PredText {
private Vector dict;
public static final String dictionaryFile = "C:/java/words.txt";
// convert a string to the corresponding signature
public static String toNumeric (String word) {
String lowerWord = word.toLowerCase();
StringBuffer result = new StringBuffer("");
for (int i = 0; i < lowerWord.length(); i++) {
char c = lowerWord.charAt(i);
if ("abc".indexOf(c) > -1) result.append("2");
else if ("def".indexOf(c) > -1) result.append("3");
else if ("ghi".indexOf(c) > -1) result.append("4");
else if ("jkl".indexOf(c) > -1) result.append("5");
else if ("mno".indexOf(c) > -1) result.append("6");
else if ("pqrs".indexOf(c) > -1) result.append("7");
else if ("tuv".indexOf(c) > -1) result.append("8");
else if ("wxyz".indexOf(c) > -1) result.append("9");
else if (" ".indexOf(c) > -1) result.append("9");
else result.append("?");
return result.toString();
// find all the words corresponding to a signature
public Vector findMatches(String sig) {
WordSig ws = new WordSig(sig, "");
WordSig newws;
Vector results = new Vector();
int index;
index = Collections.binarySearch(dict, ws);
if (index < 0){
// no matches! :(
// try to get the string that starts with a substring like ours.
index=-1-index;
if (((WordSig)dict.get(index)).getSig().startsWith(sig)) {
// no word found. we return those starting with the
// same signature
newws = (WordSig) dict.get(index);
results.addElement(newws.getWord().substring(0,sig.length()));
return results;
} else{
//no match
return results;
} else {
// go back to the first match
while(((WordSig)dict.get(index)).getSig().equals(sig) && index>0)
index--;
if (index != 0)
index++;
while ((newws = (WordSig) dict.get(index)).equals(ws)){
results.addElement( newws.getWord() );
index++;
return results;
// intialises the dictionary
public PredText () {
     String word;
String sig;
Vector dict = null;
// first try to load dict.dat
try {
System.out.print("Trying to load dict.dat...");
FileInputStream fileStream = new FileInputStream("C:/java/dict.dat");
ObjectInputStream objectStream = new ObjectInputStream(fileStream);
dict = (Vector) objectStream.readObject();
fileStream.close();
System.out.println(" done.");
}catch (ClassNotFoundException classNotFoundException) {
     System.out.println("Unable to create an object");     
catch (IOException e) {
// exception: create the dictionary
System.out.println("Error. I'm going to recreate the dictionary file");
try {
dict = createDict();
catch (IOException ioe) {
System.err.println("Error while creating dictionary file. Exiting." + e);
System.exit(1);
this.dict = dict;
// create the dictionary serialised file
public Vector createDict () throws IOException {
String word;
Vector dict = new Vector();
//open the dictionary file
System.out.print("Reading the dictionary... ");
BufferedReader dictFile = new BufferedReader(
new FileReader(dictionaryFile));
//insert each word into the data structure
while ((word = dictFile.readLine()) != null) {
word = word.toLowerCase();
dict.addElement(new WordSig(toNumeric(word), word));
// List list = dict.subList(0, dict.size());
List list = dict.subList(0, dict.size());
Collections.sort(list);
System.out.println("done.");
System.out.print("Writing the dictionary... ");
FileOutputStream fileStream = new FileOutputStream("C:/java/dict.dat");
ObjectOutputStream objectStream = new ObjectOutputStream(fileStream);
objectStream.writeObject(dict);
objectStream.flush();
fileStream.close();
System.out.println("done.");
return dict;
public static void main (String args[]) {
     PredText pt = new PredText();
if (args.length == 0) {
// no arguments, find the largest clash
     Vector result;
     Enumeration e = pt.dict.elements();
String currentSig = "";
String prevSig = "";
int clash = 0;
int maxClash = 0;
String clashSig = "";
while (e.hasMoreElements()) {
WordSig ws = (WordSig) e.nextElement();
currentSig = ws.getSig();
if (currentSig.equals(prevSig)) {
// another word with the same signature
clash ++;
} else {
// new signature: check if the previous one led
// to a maximal clash
if (clash > maxClash) {
clashSig = prevSig;
maxClash = clash;
clash = 1;
prevSig = currentSig;
result = pt.findMatches(clashSig);
System.out.println("The signature leading to most clashes is "
+ clashSig + " with " + result.size() +
" number of clashes");
for (int j = 0; j < result.size(); j++) {
System.out.println((String)result.get(j));
} else if ("0123456789".indexOf(args[0].charAt(0)) > -1){
// numeric input: find the matches for the argument
Vector result;
result = pt.findMatches(args[0]);
for (int j = 0; j < result.size(); j++) {
System.out.println((String)result.get(j));
} else {
// convert each word to the corresponding signature
for (int i = 0; i < args.length; i++) {
System.out.print(toNumeric(args) + " ");
class WordSig implements Comparable, Serializable {
String word;
String sig;
public WordSig (String sig, String word) {
this.sig = sig;
this.word = word;
public String getSig () {
return this.sig;
public String getWord() {
return this.word;
public int compareTo (Object ws) {
return sig.compareTo(((WordSig) ws).getSig());
public boolean equals (Object ws) {
return sig.equals(((WordSig) ws).getSig());
public String toString () {
return sig + ", " + word;