Java实现RS485串口通信，发送和接收数据进行解析
最近项目有一个空气检测仪，需要得到空气检测仪的实时数据，保存到数据库当中。根据了解得到，硬件是通过rs485进行串口通讯的，需要发送16进制命令给仪器，然后通过轮询来得到数据。
需要先要下载RXTX的jar包，win64位下载地址：http://pan.baidu.com/s/1o6zLmTc）；将解压后的rxtxParallel.dll和rxtxSerial.dll两个文件放在%JAVA_HOME%/jre/bin目录下,这样该包才能被正常的加载和调用。
代码如下：
package com.gpdi.sericlport; import gnu.io.*; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.sql.PreparedStatement; import java.sql.Connection; import java.sql.SQLException; import java.sql.Timestamp; import java.text.SimpleDateFormat; import java.util.*; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import com.gpdi.utils.*; public class ContinueRead extends Thread implements SerialPortEventListener { // SerialPortEventListener // 监听器,我的理解是独立开辟一个线程监听串口数据 // 串口通信管理类 static CommPortIdentifier portId; /* 有效连接上的端口的枚举 */ static Enumeration<?> portList; InputStream inputStream; // 从串口来的输入流 static OutputStream outputStream;// 向串口输出的流 static SerialPort serialPort; // 串口的引用 // 堵塞队列用来存放读到的数据 private BlockingQueue<String> msgQueue = new LinkedBlockingQueue<String>(); @Override /** * SerialPort EventListene 的方法,持续监听端口上是否有数据流 */ public void serialEvent(SerialPortEvent event) {// switch (event.getEventType()) { case SerialPortEvent.BI: case SerialPortEvent.OE: case SerialPortEvent.FE: case SerialPortEvent.PE: case SerialPortEvent.CD: case SerialPortEvent.CTS: case SerialPortEvent.DSR: case SerialPortEvent.RI: case SerialPortEvent.OUTPUT_BUFFER_EMPTY: break; case SerialPortEvent.DATA_AVAILABLE:// 当有可用数据时读取数据 byte[] readBuffer = null; int availableBytes = 0; try { availableBytes = inputStream.available(); while (availableBytes > 0) { readBuffer = ContinueRead.readFromPort(serialPort); String needData = printHexString(readBuffer); System.out.println(new Date() + "真实收到的数据为：-----" + needData); availableBytes = inputStream.available(); msgQueue.add(needData); } } catch (IOException e) { } default: break; } } /** * 从串口读取数据 * * @param serialPort 当前已建立连接的SerialPort对象 * @return 读取到的数据 */ public static byte[] readFromPort(SerialPort serialPort) { InputStream in = null; byte[] bytes = {}; try { in = serialPort.getInputStream(); // 缓冲区大小为一个字节 byte[] readBuffer = new byte[1]; int bytesNum = in.read(readBuffer); while (bytesNum > 0) { bytes = MyUtils.concat(bytes, readBuffer); bytesNum = in.read(readBuffer); } } catch (IOException e) { e.printStackTrace(); } finally { try { if (in != null) { in.close(); in = null; } } catch (IOException e) { e.printStackTrace(); } } return bytes; } /** * 通过程序打开COM4串口，设置监听器以及相关的参数 * * @return 返回1 表示端口打开成功，返回 0表示端口打开失败 */ public int startComPort() { // 通过串口通信管理类获得当前连接上的串口列表 portList = CommPortIdentifier.getPortIdentifiers(); while (portList.hasMoreElements()) { // 获取相应串口对象 portId = (CommPortIdentifier) portList.nextElement(); System.out.println("设备类型：--->" + portId.getPortType()); System.out.println("设备名称：---->" + portId.getName()); // 判断端口类型是否为串口 if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) { // 判断如果COM4串口存在，就打开该串口 if (portId.getName().equals(portId.getName())) { try { // 打开串口名字为COM_4(名字任意),延迟为1000毫秒 serialPort = (SerialPort) portId.open(portId.getName(), 1000); } catch (PortInUseException e) { System.out.println("打开端口失败!"); e.printStackTrace(); return 0; } // 设置当前串口的输入输出流 try { inputStream = serialPort.getInputStream(); outputStream = serialPort.getOutputStream(); } catch (IOException e) { e.printStackTrace(); return 0; } // 给当前串口添加一个监听器 try { serialPort.addEventListener(this); } catch (TooManyListenersException e) { e.printStackTrace(); return 0; } // 设置监听器生效，即：当有数据时通知 serialPort.notifyOnDataAvailable(true); // 设置串口的一些读写参数 try { // 比特率、数据位、停止位、奇偶校验位 serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); } catch (UnsupportedCommOperationException e) { e.printStackTrace(); return 0; } return 1; } } } return 0; } @Override public void run() { // TODO Auto-generated method stub try { System.out.println("--------------任务处理线程运行了--------------"); while (true) { // 如果堵塞队列中存在数据就将其输出 if (msgQueue.size() > 0) { String vo = msgQueue.peek(); String vos[] = vo.split(" ", -1); getData(vos); sendOrder(); msgQueue.take(); } } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * @Description: 发送获取数据指令 * @Param: * @return: * @Author: LiangZF * @Date: 2019/1/3 */ public void sendOrder() { try { Thread.sleep(3000); } catch (InterruptedException e) { e.printStackTrace(); } int i = 1; if (i == 1) { // 启动线程来处理收到的数据 try { byte[] b = new byte[]{0x01, 0x03, 0x00, 0x00, 0x00, 0x0E, (byte) 0xC4, 0x0E}; System.out.println("发送的数据:" + b); System.out.println("发出字节数：" + b.length); outputStream.write(b); outputStream.flush(); } catch (IOException e) { // TODO Auto-generated catch block serialPort.close(); e.printStackTrace(); } finally { try { if (outputStream != null) { outputStream.close(); } } catch (IOException e) { e.printStackTrace(); } } } } /** * @Description:通过数组解析检测数据 * @Param: [vo] * @return: void * @Author: LiangZF * @Date: 2019/1/4 */ public void getData(String[] vos) { // 数组不为空 if (vos != null || vos.length != 0) { // 风向数据 long wind_direction = getNum(vos[3], vos[4]); System.out.println(wind_direction); // 风速数据 long wind_speech = getNum(vos[5], vos[6]); System.out.println(wind_speech); // pm2.5 long polutionPm2 = getNum(vos[7], vos[8]); System.out.println(polutionPm2); // pm10 long polutionPm10 = getNum(vos[9], vos[10]); System.out.println(polutionPm10); // VOC long voc = getNum(vos[11], vos[12]); System.out.println(voc); // 温度 long polutionPm = getNum(vos[13], vos[14]) / 10; System.out.println(polutionPm); // 湿度 long temperature = getNum(vos[15], vos[16]) / 10; System.out.println(temperature); // 大气压力 long atmosphericPressure = getNum(vos[17], vos[18]); System.out.println(atmosphericPressure); // 臭氧 long ozone = getNum(vos[19], vos[20]) / 1000; System.out.println(ozone); // CO long co = getNum(vos[21], vos[22]) / 100; System.out.println(co); Map<String, Long> map = new HashMap<>(); map.put("O3", ozone); map.put("PM2.5", polutionPm2); map.put("PM10", polutionPm10); Map<String, Object> uu = AqiUtil.getAqiByPollutants(map); String pollutants = (String) uu.get("key"); Integer aqi = (Integer) uu.get("value"); insertDb(wind_direction, wind_speech, polutionPm2, polutionPm10, voc, polutionPm, temperature, atmosphericPressure, ozone, co, pollutants, aqi); } } // 16转10计算 public long getNum(String num1, String num2) { long value = Long.parseLong(num1, 16) * 256 + Long.parseLong(num2, 16); return value; } /** * @Description: 保存到数据库表中 * @Param: [wind_direction, wind_speech, polutionPm2, polutionPm10, voc, polutionPm, temperature, atmosphericPressure, ozone, co, pollution, aqi] * @return: void * @Author: LiangZF * @Date: 2019/1/6 */ public void insertDb(long wind_direction, long wind_speech, long polutionPm2, long polutionPm10, long voc, long polutionPm, long temperature, long atmosphericPressure, long ozone, long co, String pollution, Integer aqi) { Connection conn = null; PreparedStatement ps = null; FileInputStream in = null; try { conn = DBUtil.getConn(); String sql = "insert into air_status (wind_direction,wind_speed,particulate_matter,particulate_matter_one,voc,weather,humidity,air_pre,ozone,carbon_monoxide,del_flag,create_time,primary_pollutants,aqi)values(?,?,?,?,?,?,?,?,?,?,?,?,?,?)"; ps = conn.prepareStatement(sql); ps.setLong(1, wind_direction); ps.setLong(2, wind_speech); ps.setLong(3, polutionPm2); ps.setLong(4, polutionPm10); ps.setLong(5, voc); ps.setLong(6, polutionPm); ps.setLong(7, temperature); ps.setLong(8, atmosphericPressure); ps.setLong(9, ozone); ps.setLong(10, co); ps.setInt(11, 0); Timestamp time = new Timestamp(System.currentTimeMillis());//获取系统当前时间 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String timeStr = df.format(time); time = Timestamp.valueOf(timeStr); ps.setTimestamp(12, time); ps.setString(13, pollution); ps.setInt(14, aqi); int count = ps.executeUpdate(); if (count > 0) { System.out.println("插入成功！"); } else { System.out.println("插入失败！"); } } catch (Exception e) { e.printStackTrace(); } finally { DBUtil.closeConn(conn); if (null != ps) { try { ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } } public static void main(String[] args) { ContinueRead cRead = new ContinueRead(); System.out.println("asdasd"); int i = cRead.startComPort(); if (i == 1) { // 启动线程来处理收到的数据 cRead.start(); try { //根据提供的文档给出的发送命令，发送16进制数据给仪器 byte[] b = new byte[]{0x01, 0x03, 0x00, 0x00, 0x00, 0x0E, (byte) 0xC4, 0x0E}; System.out.println("发送的数据:" + b); System.out.println("发出字节数：" + b.length); outputStream.write(b); outputStream.flush(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try { if (outputStream != null) { outputStream.close(); } } catch (IOException e) { e.printStackTrace(); } } } else { return; } } // 字节数组转字符串 private String printHexString(byte[] b) { StringBuffer sbf = new StringBuffer(); for (int i = 0; i < b.length; i++) { String hex = Integer.toHexString(b[i] & 0xFF); if (hex.length() == 1) { hex = '0' + hex; } sbf.append(hex.toUpperCase() + " "); } return sbf.toString().trim(); } }
MyUtils工具类
因为得到的byte数组会分成几段，需要进行合并数组操作。
/** * 合并数组 * * @param firstArray 第一个数组 * @param secondArray 第二个数组 * @return 合并后的数组 */ public static byte[] concat(byte[] firstArray, byte[] secondArray) { if (firstArray == null || secondArray == null) { if (firstArray != null) return firstArray; if (secondArray != null) return secondArray; return null; } byte[] bytes = new byte[firstArray.length + secondArray.length]; System.arraycopy(firstArray, 0, bytes, 0, firstArray.length); System.arraycopy(secondArray, 0, bytes, firstArray.length, secondArray.length); return bytes; }
参考文章：https://blog.csdn.net/update_java/article/details/46898937
