datasm.java

SMPP（点到点短消息协议）的java实现

package ie.omk.smpp.message;

import ie.omk.smpp.Address;
import ie.omk.smpp.util.GSMConstants;
import ie.omk.smpp.util.SMPPIO;

import java.io.OutputStream;

/**
 * Transfer data between the SC and an ESME. This message type is used to
 * transfer data both by the SMSC and the ESME. The command can be used as a
 * replacement for both submit_sm and deliver_sm. Relevant inherited fields from
 * SMPPPacket: <br>
 * <ul>
 * serviceType <br>
 * source <br>
 * destination <br>
 * esmClass <br>
 * registered <br>
 * dataCoding <br>
 * </ul>
 * 
 * @author Oran Kelly
 * @version 1.0
 */
public class DataSM extends ie.omk.smpp.message.SMPPRequest {
    /**
     * Construct a new DataSM
     */
    public DataSM() {
        super(DATA_SM);
    }

    /**
     * Construct a new DataSM with specified sequence number.
     * 
     * @param seqNum
     *            The sequence number to use
     * @deprecated
     */
    public DataSM(int seqNum) {
        super(DATA_SM, seqNum);
    }

    /**
     * Return the number of bytes this packet would be encoded as to an
     * OutputStream.
     * 
     * @return the number of bytes this packet would encode as.
     */
    public int getBodyLength() {
        int len = ((serviceType != null) ? serviceType.length() : 0)
                + ((source != null) ? source.getLength() : 3)
                + ((destination != null) ? destination.getLength() : 3);

        // 3 1-byte integers, 1 c-string
        return len + 4;
    }

    /**
     * Write a byte representation of this packet to an OutputStream
     * 
     * @param out
     *            The OutputStream to write to
     * @throws java.io.IOException
     *             If an error occurs writing to the output stream.
     */
    protected void encodeBody(OutputStream out) throws java.io.IOException {
        SMPPIO.writeCString(serviceType, out);
        if (source != null) {
            source.writeTo(out);
        } else {
            // Write ton=0(null), npi=0(null), address=\0(nul)
            new Address(GSMConstants.GSM_TON_UNKNOWN,
                    GSMConstants.GSM_NPI_UNKNOWN, "").writeTo(out);
        }
        if (destination != null) {
            destination.writeTo(out);
        } else {
            // Write ton=0(null), npi=0(null), address=\0(nul)
            new Address(GSMConstants.GSM_TON_UNKNOWN,
                    GSMConstants.GSM_NPI_UNKNOWN, "").writeTo(out);
        }

        SMPPIO.writeInt(esmClass, 1, out);
        SMPPIO.writeInt(registered, 1, out);
        SMPPIO.writeInt(dataCoding, 1, out);
    }

    public void readBodyFrom(byte[] body, int offset)
            throws SMPPProtocolException {
        // First the service type
        serviceType = SMPPIO.readCString(body, offset);
        offset += serviceType.length() + 1;

        source = new Address();
        source.readFrom(body, offset);
        offset += source.getLength();

        destination = new Address();
        destination.readFrom(body, offset);
        offset += destination.getLength();

        // ESM class, protocol Id, priorityFlag...
        esmClass = SMPPIO.bytesToInt(body, offset++, 1);

        // Registered delivery, data coding
        registered = SMPPIO.bytesToInt(body, offset++, 1);
        dataCoding = SMPPIO.bytesToInt(body, offset++, 1);
    }

    /**
     * Convert this packet to a String. Not to be interpreted programmatically,
     * it's just dead handy for debugging!
     */
    public String toString() {
        return new String("data_sm");
    }
}