com.github.pires.obd.commands.ObdCommand Maven / Gradle / Ivy

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/**
 * 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 com.github.pires.obd.commands;

import com.github.pires.obd.commands.control.TroubleCodesObdCommand;
import com.github.pires.obd.commands.protocol.ObdProtocolCommand;
import com.github.pires.obd.exceptions.BusInitException;
import com.github.pires.obd.exceptions.MisunderstoodCommandException;
import com.github.pires.obd.exceptions.NoDataException;
import com.github.pires.obd.exceptions.NonNumericResponseException;
import com.github.pires.obd.exceptions.ObdResponseException;
import com.github.pires.obd.exceptions.StoppedException;
import com.github.pires.obd.exceptions.UnableToConnectException;
import com.github.pires.obd.exceptions.UnknownObdErrorException;
import com.github.pires.obd.exceptions.UnsupportedCommandException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;

/**
 * Base OBD command.
 */
public abstract class ObdCommand {

  protected ArrayList buffer = null;
  protected String cmd = null;
  protected boolean useImperialUnits = false;
  protected String rawData = null;
  protected long responseTimeDelay = 200;
  /**
   * Error classes to be tested in order
   */
  private final Class[] ERROR_CLASSES = {
    UnableToConnectException.class,
    BusInitException.class,
    MisunderstoodCommandException.class,
    NoDataException.class,
    StoppedException.class,
    UnknownObdErrorException.class,
    UnsupportedCommandException.class
  };

  /**
   * Default ctor to use
   *
   * @param command
   * the command to send
   */
  public ObdCommand(String command) {
    this.cmd = command;
    this.buffer = new ArrayList();
    if (!(this instanceof ObdProtocolCommand) && !(this instanceof TroubleCodesObdCommand)) {
      this.cmd += " 1";//speed up
    }
  }

  /**
   * Prevent empty instantiation
   */
  private ObdCommand() {
  }

  /**
   * Copy ctor.
   *
   * @param other
   * the ObdCommand to copy.
   */
  public ObdCommand(ObdCommand other) {
    this(other.cmd);
  }

  /**
   * Sends the OBD-II request and deals with the response.
   *
   * This method CAN be overriden in fake commands.
   *
   * @param in a {@link java.io.InputStream} object.
   * @param out a {@link java.io.OutputStream} object.
   * @throws java.io.IOException if any.
   * @throws java.lang.InterruptedException if any.
   */
  public void run(InputStream in, OutputStream out) throws IOException,
      InterruptedException {
    sendCommand(out);
    readResult(in);
  }

  /**
   * Sends the OBD-II request.
   *
   * This method may be overriden in subclasses, such as ObMultiCommand or
   * TroubleCodesObdCommand.
   *
   * @param out
   * The output stream.
   * @throws java.io.IOException if any.
   * @throws java.lang.InterruptedException if any.
   */
  protected void sendCommand(OutputStream out) throws IOException,
      InterruptedException {
    // write to OutputStream (i.e.: a BluetoothSocket) with an added
    // Carriage return
    out.write((cmd + "\r").getBytes());
    out.flush();

    /*
     * HACK GOLDEN HAMMER ahead!!
     *
     * Due to the time that some systems may take to respond, let's give it
     * 200ms.
     */
    Thread.sleep(responseTimeDelay);
  }

  /**
   * Resends this command.
   *
   * @param out a {@link java.io.OutputStream} object.
   * @throws java.io.IOException if any.
   * @throws java.lang.InterruptedException if any.
   */
  protected void resendCommand(OutputStream out) throws IOException,
      InterruptedException {
    out.write("\r".getBytes());
    out.flush();
  }

  /**
   * Reads the OBD-II response.
   * 
   * This method may be overriden in subclasses, such as ObdMultiCommand.
   *
   * @param in a {@link java.io.InputStream} object.
   * @throws java.io.IOException if any.
   */
  protected void readResult(InputStream in) throws IOException {
    readRawData(in);
    checkForErrors();
    fillBuffer();
    performCalculations();
  }

  /**
   * This method exists so that for each command, there must be a method that is
   * called only once to perform calculations.
   */
  protected abstract void performCalculations();

  /**
   *
   */
  protected void fillBuffer() {
    rawData = rawData.replaceAll("\\s", ""); //removes all [ \t\n\x0B\f\r]
    rawData = rawData.replaceAll("(BUS INIT)|(BUSINIT)|(\\.)", "");
    
    if (!rawData.matches("([0-9A-F])+")) {
      throw new NonNumericResponseException(rawData);
    }

    // read string each two chars
    buffer.clear();
    int begin = 0;
    int end = 2;
    while (end <= rawData.length()) {
      buffer.add(Integer.decode("0x" + rawData.substring(begin, end)));
      begin = end;
      end += 2;
    }
  }

  /**
   * 

   * readRawData.
   *
   * @param in a {@link java.io.InputStream} object.
   * @throws java.io.IOException if any.
   */
  protected void readRawData(InputStream in) throws IOException {
    byte b = 0;
    StringBuilder res = new StringBuilder();

    // read until '>' arrives
    while ((char) (b = (byte) in.read()) != '>') {
      res.append((char) b);
    }

    /*
     * Imagine the following response 41 0c 00 0d.
     *
     * ELM sends strings!! So, ELM puts spaces between each "byte". And pay
     * attention to the fact that I've put the word byte in quotes, because 41
     * is actually TWO bytes (two chars) in the socket. So, we must do some more
     * processing..
     */
    rawData = res.toString().replaceAll("SEARCHING", "");

    /*
     * Data may have echo or informative text like "INIT BUS..." or similar.
     * The response ends with two carriage return characters. So we need to take
     * everything from the last carriage return before those two (trimmed above).
     */
    //kills multiline.. rawData = rawData.substring(rawData.lastIndexOf(13) + 1);
    rawData = rawData.replaceAll("\\s", "");//removes all [ \t\n\x0B\f\r]
  }

  void checkForErrors() {
    for (Class errorClass : ERROR_CLASSES) {
      ObdResponseException messageError;

      try {
        messageError = errorClass.newInstance();
        messageError.setCommand(this.cmd);
      } catch (InstantiationException e) {
        throw new RuntimeException(e);
      } catch (IllegalAccessException e) {
        throw new RuntimeException(e);
      }

      if (messageError.isError(rawData)) {
        throw messageError;
      }
    }
  }

  /**
   * @return the raw command response in string representation.
   */
  public String getResult() {
    return rawData;
  }

  /**
   * @return a formatted command response in string representation.
   */
  public abstract String getFormattedResult();

  /**
   * @return a list of integers
   */
  protected ArrayList getBuffer() {
    return buffer;
  }

  /**
   * @return true if imperial units are used, or false otherwise
   */
  public boolean useImperialUnits() {
    return useImperialUnits;
  }

  /**
   * Set to 'true' if you want to use imperial units, false otherwise. By
   * default this value is set to 'false'.
   *
   * @param isImperial a boolean.
   */
  public void useImperialUnits(boolean isImperial) {
    this.useImperialUnits = isImperial;
  }

  /**
   * @return the OBD command name.
   */
  public abstract String getName();
  
    /**
   * Time the command waits before returning from #sendCommand()
   * @return delay in ms
   */
  public long getResponseTimeDelay() {
    return responseTimeDelay;
  }

  /**
   * Time the command waits before returning from #sendCommand()
   * @param responseTimeDelay
   */
  public void setResponseTimeDelay(long responseTimeDelay) {
    this.responseTimeDelay = responseTimeDelay;
  }

}