java 读取串口 com 外部设备

/* * To change this template, choose Tools | Templates * and open the template in the editor. */package CalcWgtPro;/** * * @author luolai */import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.util.Iterator;import java.util.List;import java.util.TooManyListenersException;import javax.comm.CommPortIdentifier;import javax.comm.PortInUseException;import javax.comm.SerialPort;import javax.comm.SerialPortEvent;import javax.comm.SerialPortEventListener;import javax.comm.UnsupportedCommOperationException;public class Readst {    static String retValue = "000000";    public void init() {        try {            CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier("COM1");            // 直接取得COM3端口            System.out.println(portId.getName() + ":开启");            LogInfo.appendLog(portId.getName() + ":开启");            @SuppressWarnings("unused")            Read reader = new Read(portId);        } catch (Exception ex) {            ex.printStackTrace();            LogInfo.appendLog(ex.getMessage());        }    }    class Read implements Runnable, SerialPortEventListener {        InputStream inputStream;        SerialPort serialPort;        Thread readThread;        public Read(CommPortIdentifier portId) throws InterruptedException {            try {                serialPort = (SerialPort) portId.open("MyReader", 2000);                //portId.open("串口所有者名称", 超时等待时间);            } catch (PortInUseException e) {                //如果端口被占用就抛出这个异常                e.printStackTrace();                LogInfo.appendLog(e.getMessage());            }            try {                inputStream = serialPort.getInputStream();                //从COM3获取数据                } catch (IOException e) {                LogInfo.appendLog(e.getMessage());            }            try {                serialPort.addEventListener(this);                //添加监听器            } catch (TooManyListenersException e) {            }            serialPort.notifyOnDataAvailable(true);            /*             * 侦听到串口有数据,触发串口事件             */            try {                serialPort.setSerialPortParams(2400,//波特率                        SerialPort.DATABITS_8,//数据位数                        SerialPort.STOPBITS_1,//停止位                        SerialPort.PARITY_NONE);//校验            } catch (UnsupportedCommOperationException e) {            }            readThread = new Thread(this);            readThread.start();            //启动线程        }        public void run() {            try {                Thread.sleep(2000);                serialPort.close();                System.out.println("COM1:关闭");                //设定30秒后端口关闭，程序随之结束            } catch (InterruptedException e) {                LogInfo.appendLog(e.getMessage());            }        }        /**         * BI -通讯中断. CD -载波检测. CTS -清除发送. DATA_AVAILABLE -有数据到达. DSR -数据设备准备好.         * FE -帧错误. OE -溢位错误. OUTPUT_BUFFER_EMPTY -输出缓冲区已清空. PE -奇偶校验错. RI -         * 振铃指示. 一般最常用的就是DATA_AVAILABLE--串口有数据到达事件。         */        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:                    byte[] readBuffer = new byte[20];                    try {                        while (inputStream.available() > 0) {                            //int numBytes = inputStream.read(readBuffer);                            //System.out.println("numBytes" + numBytes);                            //retValue = new String(readBuffer).trim();                            //System.out.println(retValue);                            BufferedReader comReader = new BufferedReader(new InputStreamReader(inputStream));                            String temp = comReader.readLine().trim();                            System.out.println(comReader.read() + ":" + temp);                            if (temp.indexOf("#0") >= 0 || temp.indexOf("#8") >= 0) {                                int p = temp.indexOf("#");                                temp = temp.substring(p + 3, temp.length()).replace(" ", "").trim();                                try {                                    Integer.parseInt(temp);                                } catch (Exception e) {                                    System.out.println("忽略次数据:" + temp);                                    LogInfo.appendLog("忽略次数据:" + temp);                                    retValue = "0";                                    return;                                }                                System.out.println(temp);                                retValue = String.valueOf(Integer.parseInt(temp.substring(1, 5))) + "." + temp.substring(5, 6);                                System.out.println(retValue);                            }                        }                        //strWGT = new String(readBuffer).trim();                        //System.out.println(strWGT);                        //输出读入的字符                    } catch (IOException e) {                        LogInfo.appendLog(e.getMessage());                    }                    break;            }        }    }    public static void main(String[] args) {        Readst reader = new Readst();        reader.init();        reader.retValue = "0";        //(reader.retValue);    }}//此程序只用于监听COM3端口，当程序执行时开启COM3端口，等待30秒后，端口COM3关闭，程序随之关闭//Read 为内部类，这样可以共用读取出来的字符串信息//在Readstr 中定义一个静态变量static String str = "000000";//然后在读出数据后str = new String(readBuffer).trim();//这样可以在一个事件触发后，将str中的值赋给相应的值(比如说，让这个值显示在输入框中)