/*
 * Copyright 2016 Gabor Somogyi (gabor.g.somogyi@gmail.com)
 *
 * 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 org.traccar.protocol;

import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.traccar.StringProtocolEncoder;
import org.traccar.helper.Log;
import org.traccar.model.Command;

public class H02ProtocolEncoder extends StringProtocolEncoder {

    private static final String MARKER = "HQ";

    private Object formatCommand(DateTime time, String uniqueId, String type, String... params) {

        String result = String.format("*%s,%s,%s,%02d%02d%02d",
                MARKER, uniqueId, type, time.getHourOfDay(), time.getMinuteOfHour(), time.getSecondOfMinute());

        for (String param : params) {
            result += "," + param;
        }

        result += "#";

        return result;
    }

    protected Object encodeCommand(Command command, DateTime time) {
        String uniqueId = getUniqueId(command.getDeviceId());

        switch (command.getType()) {
            case Command.TYPE_ALARM_ARM:
                return formatCommand(time, uniqueId, "SCF", "0", "0");
            case Command.TYPE_ALARM_DISARM:
                return formatCommand(time, uniqueId, "SCF", "1", "1");
            case Command.TYPE_ENGINE_STOP:
                return formatCommand(
                        time, uniqueId, "S20", "1", "3", "10", "3", "5", "5", "3", "5", "3", "5", "3", "5");
            case Command.TYPE_ENGINE_RESUME:
                return formatCommand(time, uniqueId, "S20", "0", "0");
            case Command.TYPE_POSITION_PERIODIC:
                return formatCommand(
                        time, uniqueId, "S71", "22", command.getAttributes().get(Command.KEY_FREQUENCY).toString());
            default:
                Log.warning(new UnsupportedOperationException(command.getType()));
                break;
        }

        return null;
    }

    @Override
    protected Object encodeCommand(Command command) {
        return encodeCommand(command, new DateTime(DateTimeZone.UTC));
    }

}

@@ -56,16 +56,76 @@
 il.com)%0A
+ *           2016 Anton Tananaev (anton.tananaev@gmail.com)%0A
  *%0A * Li
@@ -1110,16 +1110,23 @@
   String
+Builder
  result 
@@ -1127,16 +1127,34 @@
 esult = 
+new StringBuilder(
 String.f
@@ -1295,16 +1295,17 @@
 inute())
+)
 ;%0A%0A     
@@ -1359,23 +1359,34 @@
 sult
- += %22,%22 + 
+.append(%22,%22).append(
 param
+)
 ;%0A  
@@ -1412,15 +1412,20 @@
 sult
- += 
+.append(
 %22#%22
+)
 ;%0A%0A 
@@ -1444,16 +1444,27 @@
 n result
+.toString()
 ;%0A    %7D%0A

Use string buffer for concatenation