ModbusResponse.java

/***
 * Copyright 2002-2010 jamod development team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ***/

package net.wimpi.modbus.msg;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;

import net.wimpi.modbus.Modbus;

/**
 * Abstract class implementing a <tt>ModbusResponse</tt>.
 * This class provides specialised implementations with
 * the functionality they have in common.
 *
 * @author Dieter Wimberger
 * @version @version@ (@date@)
 */
public abstract class ModbusResponse extends ModbusMessageImpl {

    /**
     * Utility method to set the raw data of the message.
     * Should not be used except under rare circumstances.
     * <p>
     *
     * @param msg the <tt>byte[]</tt> resembling the raw modbus
     *            response message.
     */
    protected void setMessage(byte[] msg) {
        try {
            readData(new DataInputStream(new ByteArrayInputStream(msg)));
        } catch (IOException ex) {

        }
    }// setMessage

    /**
     * Factory method creating the required specialized <tt>ModbusResponse</tt>
     * instance.
     *
     * @param functionCode the function code of the response as <tt>int</tt>.
     * @return a ModbusResponse instance specific for the given function code.
     */
    public static ModbusResponse createModbusResponse(int functionCode) {
        ModbusResponse response = null;

        switch (functionCode) {
            case Modbus.READ_MULTIPLE_REGISTERS:
                response = new ReadMultipleRegistersResponse();
                break;
            case Modbus.READ_INPUT_DISCRETES:
                response = new ReadInputDiscretesResponse();
                break;
            case Modbus.READ_INPUT_REGISTERS:
                response = new ReadInputRegistersResponse();
                break;
            case Modbus.READ_COILS:
                response = new ReadCoilsResponse();
                break;
            case Modbus.WRITE_MULTIPLE_REGISTERS:
                response = new WriteMultipleRegistersResponse();
                break;
            case Modbus.WRITE_SINGLE_REGISTER:
                response = new WriteSingleRegisterResponse();
                break;
            case Modbus.WRITE_COIL:
                response = new WriteCoilResponse();
                break;
            case Modbus.WRITE_MULTIPLE_COILS:
                response = new WriteMultipleCoilsResponse();
                break;
            default:
                response = new ExceptionResponse();
                break;
        }
        return response;
    }// createModbusResponse

}// class ModbusResponse