| /* |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you 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.apache.edgent.samples.connectors.elm327.runtime; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| |
| import org.apache.edgent.samples.connectors.elm327.Cmd; |
| import org.apache.edgent.samples.connectors.elm327.Elm327Cmds; |
| |
| import com.google.gson.JsonObject; |
| |
| /** |
| * Runtime execution of ELM327 & OBD-II commands. |
| * |
| */ |
| public class CommandExecutor { |
| |
| public static int[] binary(byte[] reply, int offset, int length) { |
| int[] binary = new int[length / 2]; |
| for (int i = 0; i < binary.length; i++) { |
| int h = Character.digit(reply[offset++], 16); |
| int l = Character.digit(reply[offset++], 16); |
| binary[i] = ((h * 16) + l); |
| } |
| return binary; |
| } |
| |
| public static void initialize(Cmd protocol, OutputStream out, InputStream in) { |
| try { |
| |
| executeUntilOK(10, Elm327Cmds.INIT, out, in); |
| Thread.sleep(1000); |
| |
| executeUntilOK(1, Elm327Cmds.ECHO_OFF, out, in); |
| |
| executeUntilOK(1, protocol, out, in); |
| executeUntilOK(1, Elm327Cmds.SLOW_INIT, out, in); |
| Thread.sleep(1000); |
| |
| } catch (Exception ioe) { |
| throw new RuntimeException(ioe); |
| } |
| } |
| |
| private static boolean readUntilPrompt(InputStream in, ByteArrayOutputStream bytes) throws IOException { |
| bytes.reset(); |
| for (;;) { |
| int b = in.read(); |
| if (b == -1) |
| return false; |
| if (b == ' ') |
| continue; |
| if (b == '\r') |
| continue; |
| if (b == '>') |
| return true; |
| |
| bytes.write(b); |
| } |
| } |
| |
| public static JsonObject executeUntilOK(int n, Cmd cmd, OutputStream out, InputStream in) throws IOException { |
| try (ByteArrayOutputStream bytes = new ByteArrayOutputStream(16)) { |
| for (int i = 0; i < n; i++) { |
| cmd.writeCmd(out); |
| out.flush(); |
| |
| if (!readUntilPrompt(in, bytes)) |
| continue; |
| |
| byte[] reply = bytes.toByteArray(); |
| JsonObject j = new JsonObject(); |
| if (cmd.result(j, reply)) |
| return j; |
| break; |
| } |
| } |
| throw new IllegalStateException("Could not execute command:" + cmd); |
| } |
| |
| public static JsonObject execute(Cmd cmd, OutputStream out, InputStream in) { |
| try (ByteArrayOutputStream bytes = new ByteArrayOutputStream(16)) { |
| cmd.writeCmd(out); |
| out.flush(); |
| |
| JsonObject result = new JsonObject(); |
| result.addProperty(Cmd.PID, cmd.id()); |
| result.addProperty(Cmd.TS, System.currentTimeMillis()); |
| |
| readUntilPrompt(in, bytes); |
| |
| cmd.result(result, bytes.toByteArray()); |
| |
| return result; |
| } catch (IOException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| } |