readcomm.java

linux下的串口编程,清注意端口的差别。

/******************************************
 *　程序文件名称：ReadComm.java
 * 功能：从串行口COM1中接收数据
 ******************************************/
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.comm.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;


class R_Frame extends JFrame implements Runnable, ActionListener,
		SerialPortEventListener {
	/* 检测系统中可用的通讯端口类 */
	static CommPortIdentifier portId;
	/* Enumeration 为枚举型类,在java.util中 */
	static Enumeration portList;
	InputStream inputStream;
	/* 声明RS-232串行端口的成员变量 */
	SerialPort serialPort;
	/** 读取串口线程 */
	Thread readThread;
	/** 写串口线程 */
	Thread writeThread;
	
	JPanel panOut = new JPanel();
	JPanel panIn = new JPanel();
	JPanel panBtn = new JPanel();
	
	String str = "";
	JTextField txtInmessage = new JTextField("上面文本框显示接收到的数据");
	JTextArea txtArea_In = new JTextArea();

	JTextField txtOutmessage = new JTextField("上面文本框显示发送的数据");
	JTextArea txtArea_Out = new JTextArea();

	JButton btnOpen = new JButton("打开串口");
	JButton btnClose = new JButton("关闭串口");
	JButton btnSend = new JButton("发送数据");
	//发送数据变量
	byte data[] = new byte[10240];
	OutputStream outputStream;

	/* 建立窗体 */
	R_Frame() {
		this.getContentPane().setLayout(null);
		
		panBtn.setLayout(null);
		panBtn.setBounds(0,0,300,30);
		panBtn.add(btnOpen);
		panBtn.add(btnClose);
		panBtn.add(btnSend);
		btnOpen.setBounds(0, 0, 100, 30);
		btnClose.setBounds(100, 0, 100, 30);
		btnSend.setBounds(200, 0, 100, 30);
		this.getContentPane().add(panBtn);
				
		btnOpen.addActionListener(this);
		btnClose.addActionListener(this);
		btnSend.addActionListener(this);
		

		//发送区域
		panOut.setLayout(null);
		panOut.setBounds(0,30,300,200);
		txtArea_Out.setBounds(0,0,300,180);
		txtOutmessage.setBounds(0,180,300,20);
		panOut.add(txtArea_Out);
		panOut.add(txtOutmessage);
		
		this.getLayeredPane().add(panOut);
		//接受区域
		panIn.setLayout(null);
		panIn.setBounds(0,230,300,200);
		txtArea_In.setBounds(0,0,300,180);
		txtInmessage.setBounds(0,180,300,20);
		panIn.add(txtArea_In);
		panIn.add(txtInmessage);
		
		this.getLayeredPane().add(panIn);		
	} // R_Frame() end

	/* 点击按扭所触发的事件：打开串口,并监听串口. */
	public void actionPerformed(ActionEvent event) {
		if(event.getSource().equals(btnOpen)) {
			//读取用户配置端口名称
			String portName = ConfigFile.findProperty("CommPort");

			/* 获取系统中所有的通讯端口 */
			portList = CommPortIdentifier.getPortIdentifiers();
			/* 用循环结构找出串口 */
			while (portList.hasMoreElements()) {
				/* 强制转换为通讯端口类型 */
				portId = (CommPortIdentifier) portList.nextElement();
				if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
					if (portId.getName().equals(portName)) {
						try {
							serialPort = (SerialPort) portId.open("ReadComm", 2000);
							txtInmessage.setText("已打开端口COM1 ,正在接收数据..... ");
						} catch (PortInUseException e) {
						}

						/* 设置串口监听器 */
						try {
							serialPort.addEventListener(this);
						} catch (TooManyListenersException e) {
						}
						/* 侦听到串口有数据,触发串口事件 */
						serialPort.notifyOnDataAvailable(true);
						
						/* 设置串口输出流 */
						try {
							outputStream = serialPort.getOutputStream();
						} catch (IOException e) {
						}


					} // if end
				} // if end
			} // while end
			readThread = new Thread(this);
			readThread.start(); // 线程负责每接收一次数据休眠20秒钟
			
		}
		if(event.getSource().equals(btnClose)){
			
			if(serialPort!=null) {
				serialPort.close();
				txtInmessage.setText("端口已关闭");

			}
		}
		if(event.getSource().equals(btnSend)){
			/* 设置串口通讯参数 */
			try {
				serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8,
						SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
			} catch (UnsupportedCommOperationException e) {
			}
			/* 从文本区按字节读取数据 */
			data = txtArea_Out.getText().getBytes();
			/* 发送数据流(将数组data[]中的数据发送出去) */
			try {
				outputStream.write(data);
			} catch (IOException e) {
			}
		}
		
	} // actionPerformed() end

	/* 接收数据后休眠20秒钟 */
	public void run() {
		try {
			Thread.sleep(20000);
		} catch (InterruptedException e) {
		}
	} // run() end

	/* 串口监听器触发的事件，设置串口通讯参数，读取数据并写到文本区中 */
	public void serialEvent(SerialPortEvent event) {
		/* 设置串口通讯参数：波特率、数据位、停止位、奇偶校验 */
		try {
			serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8,
					SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
		} catch (UnsupportedCommOperationException e) {
		}
		byte[] readBuffer = new byte[20];
		try {
			inputStream = serialPort.getInputStream();
		} catch (IOException e) {
		}
		try {
			/* 从线路上读取数据流 */
			while (inputStream.available() > 0) {
				int numBytes = inputStream.read(readBuffer);
			} // while end
			str = new String(readBuffer);
			/* 接收到的数据存放到文本区中 */
			txtArea_In.append(str + "\n");
		} catch (IOException e) {
		}
	} // serialEvent() end
} // 类R_Frame end

public class ReadComm {
	public static void main(String args[]) {
		R_Frame frame = new R_Frame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		frame.setResizable(false); //设置窗口为固定大小

		frame.setSize(300,460);  
		frame.setLocation(200, 200);
		frame.setVisible(true);
		
	}
}