Problem in sending SMS via using java communication API

Question

I need to send SMS via my sony ericsson Z530i. It is connected to the com5 port of my system. I got the following code.
import java.io.*;
import java.util.BitSet;
import javax.comm.*;
import java.lang.*;
public class SerialToGsm {
    InputStream in;
    OutputStream out;
    String lastIndexRead;
    String senderNum;
    String smsMsg;
    SerialToGsm(String porta) {
        try {
//            CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier("com5");
            CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier(porta);
            SerialPort sp = (SerialPort)portId.open("Sms_GSM", 0);
            sp.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
            sp.setFlowControlMode(sp.FLOWCONTROL_NONE);
            in = sp.getInputStream();
            out = sp.getOutputStream();
            // modem reset
            sendAndRecv("+++AT", 30);       // delay for 20 sec/10
            sendAndRecv("AT&F", 30);
            sendAndRecv("ATE0", 30);        // echo off
            sendAndRecv("AT +CMEE=1", 30);  // verbose error messages
            sendAndRecv("AT+CMGF=0", 70);   // set pdu mode
//            sendAndRecv("AT V1E0S0=0&D2&C1", 1000000);
        catch (Exception e) {
            System.out.println("Exception " + e);
         System.exit(1);
    private String sendAndRecv(String s, int timeout) {
        try {
            // clean serial port input buffer
            in.skip(in.available());
            System.out.println("=> " + s);
            s = s + "\r";         // add CR
            out.write(s.getBytes());
            out.flush();           
            String strIn = new String();
            for (int i = 0; i < timeout; i++){
                int numChars = in.available();
                if (numChars > 0) {
                    byte[] bb = new byte[numChars];
                    in.read(bb,0,numChars);
                    strIn += new String(bb);
                // start exit conditions
                if (strIn.indexOf(">\r\n") != -1) {
                    break;
                if (strIn.indexOf("OK\r\n") != -1){
                    break;
                if (strIn.indexOf("ERROR") != -1) { // if find 'error' wait for CR+LF
                    if (strIn.indexOf("\r\n",strIn.indexOf("ERROR") + 1) != -1) {
                        break;                                            
          Thread.sleep(100); // delay 1/10 sec
            System.out.println("<= " + strIn);
            if (strIn.length() == 0) {
                return "ERROR: len 0";
            return strIn;
        catch (Exception e) {                 
            System.out.println("send e recv Exception " + e);
            return "ERROR: send e recv Exception";
    public String sendSms (String numToSend, String whatToSend) {
        ComputeSmsData sms = new ComputeSmsData();
        sms.setAsciiTxt(whatToSend);
        sms.setTelNum(numToSend);
//        sms.setSMSCTelNum("[phone]");  // SC fixed
        String s = new String();
        s = sendAndRecv("AT+CMGS=" + (sms.getCompletePduData().length() / 2) + "\r", 30);
//        System.out.println("==> AT+CMGS=" + (sms.getCompletePduData().length() / 2));
//        System.out.println("<== " + s);
        if (s.indexOf(">") != -1) {
//            s = sendAndRecv(sms.getSMSCPduData() + sms.getCompletePduData() + "\u001A"); // usefull one day?
//            System.out.println("Inviero questo >>>> " + sms.getCompletePduData());
               // if this sintax won't work try remove 00 prefix
            s = sendAndRecv("00" + sms.getCompletePduData() + "\u001A", 150);
//            System.out.println("<== " + s);
            return s;
        else {
            return "ERROR";
    // used to reset message data
    private void resetGsmObj() {
        lastIndexRead = null;
        senderNum = null;
        smsMsg = null;
    public String checkSms (){
        String str = new String();
        String strGsm = new String();                         
        strGsm = sendAndRecv("AT+CMGL=0", 30);  // list unread msg and sign them as read
        // if answer contain ERROR then ERROR
        if (strGsm.indexOf("ERROR") != -1) {
            resetGsmObj();
            return strGsm; // error
        strGsm = sendAndRecv("AT+CMGL=1", 30);  // list read msg
        // if answer contain ERROR then ERROR
        if (strGsm.indexOf("ERROR") != -1) {
            resetGsmObj();
            return strGsm; // error
        // evaluate message index
        if (strGsm.indexOf(':') <= 0) {
            resetGsmObj();
            return ("ERROR unexpected answer");
        str = strGsm.substring(strGsm.indexOf(':') + 1,strGsm.indexOf(','));
        str = str.trim(); // remove white spaces
//        System.out.println("Index: " + str);
        lastIndexRead = str;
        // find message string
        // look for start point (search \r, then skip \n, add and one more for right char
        int startPoint = strGsm.indexOf("\r",(strGsm.indexOf(":") + 1)) + 2;
        int endPoint = strGsm.indexOf("\r",startPoint + 1);
        if (endPoint == -1) {
            // only one message
            endPoint = strGsm.length();
        // extract string
        str = strGsm.substring(startPoint, endPoint);
        System.out.println("String to be decoded :" + str);
        ComputeSmsData sms = new ComputeSmsData();
        sms.setRcvdPdu(str);
//        SMSCNum = new String(sms.getRcvdPduSMSC());
        senderNum = new String(sms.getRcvdSenderNumber());
        smsMsg = new String(sms.getRcvdPduTxt());
        System.out.println("SMSC number:   " + sms.getRcvdPduSMSC());
        System.out.println("Sender number: " + sms.getRcvdSenderNumber());
        System.out.println("Message: " + sms.getRcvdPduTxt());
        return "OK";
    public String readSmsSender() {
        return senderNum;
    public String readSms() {
        return smsMsg;
    public String delSms() {  
        if (lastIndexRead != "") {               
            return sendAndRecv("AT+CMGD=" + lastIndexRead, 30);
        return ("ERROR");
}When i compile, there is no error. But when i execute it, the following error comes:
E:\java\JavaSmsApi>javac SerialToGsm.java
E:\java\JavaSmsApi>java SerialToGsm
Exception in thread "main" java.lang.NoSuchMethodError: main
What might be the error? Somebody help me. Thanks in advance.

Answer 1

You are probably trying to run this as a CLDC application instead of a MIDP application (aka a MIDLet). Since CLDC apps start with a main(....) your runtime looks for one but does not find it, hence the error. Please recheck the project configuration.