简单的Java串口通讯应答示例

java串口通讯第一次使用，找的资料都比较麻烦，一时没有理出头绪，自己在示例的基础上整理了一个简单的应答示例，比较简陋，但演示了java串口通讯的基本过程。

package com.garfield.comm;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.comm.CommPortIdentifier;
import javax.comm.SerialPort;

public class SimpleCommIO implements Runnable {

    static CommPortIdentifier portId;
    static String cmdHand = "I
";
    static String cmdWeight = "WX
";
    static SerialPort serialPort;
    static OutputStream outputStream;
    static String comm="COM11";

    InputStream inputStream;
    Thread readThread;

    public void run() {
        while (true) {
            try {
                byte[] readBuffer = new byte[200];

                try {
                    while (inputStream.available() > 0) {
                        int numBytes = inputStream.read(readBuffer);
                        System.out.print("收到数据："+new String(readBuffer));
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }


    public void initComm() {
        try{
            portId = CommPortIdentifier.getPortIdentifier(comm);
            serialPort = (SerialPort) portId.open("SimpleCommIO",2000);

            outputStream = serialPort.getOutputStream();
            inputStream = serialPort.getInputStream();

            serialPort.setSerialPortParams(9600,
                    SerialPort.DATABITS_8, 
                    SerialPort.STOPBITS_1,
                    SerialPort.PARITY_NONE);
        }catch(Exception e){
            e.printStackTrace();
        }

    }

    public void writeComm(String cmd) {
        try {
            outputStream.write(cmd.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {

        SimpleCommIO reader = new SimpleCommIO();
        reader.initComm();
        Thread readThread = new Thread(reader);
        readThread.start();
        System.out.println("发出指令："+cmdHand);
        reader.writeComm(cmdHand);
        
        //暂停一会儿
        try { 
            Thread.sleep ( 2000 ) ; 
        } catch (InterruptedException ie)
        {
            
        }
        System.out.println("发出指令："+cmdWeight);
        reader.writeComm(cmdWeight);
    }

}

另注配置：

将javacomm20-win32 .zip下载的文件解压缩后，在javacomm20-win32commapi目录下有必需的三个文件：

comm.jar，javax.comm. properties和win32comm.dll。

将文件comm.jar拷贝到%JAVA_HOME%jrelibext;

文件 javax.comm. properties拷贝到%JAVA_HOME%jrelib;

文件win32comm.dll拷贝到%JAVA_HOME%in。

注意%JAVA_HOME%是jdk的路径，而非jre。