serialbean.java

用java实现串口通信 用java实现串口通信

package communication;
import java.io.*;
import java.util.*;
import javax.comm.*;
/**

* This bean provides some basic functions to implement full dulplex
* information exchange through the srial port.
*/



public class SerialBean
{
	static String PortName;
	CommPortIdentifier portId;
	SerialPort serialPort;
	static OutputStream out;
	static InputStream in;
	SerialBuffer SB;
	ReadSerial RS;
/**
* Constructor
* @param PortID the ID of the serial to be used. 1 for COM1,
* 2 for COM2, etc.
*/
	public SerialBean(int PortID)
	{
		PortName = "COM" + PortID;
	}
/**
* This function initialize the serial port for communication. It starts a
* thread which consistently monitors the serial port. Any signal capturred
* from the serial port is stored into a buffer area.
*/
	public int Initialize()
	{
		int InitSuccess = 1;
		int InitFail = -1;
		try
		{
			portId = CommPortIdentifier.getPortIdentifier(PortName);
			try
			{
				serialPort = (SerialPort)
				portId.open("Serial_Communication", 2000);
			} catch (PortInUseException e)
			{
				return InitFail;
			}



		//Use InputStream in to read from the serial port, and OutputStream



		//out to write to the serial port.



			try
			{
				in = serialPort.getInputStream();
				out = serialPort.getOutputStream();
			} catch (IOException e)
			{
				return InitFail;
			}
		//Initialize the communication parameters to 9600, 8, 1, none.
			try
			{
				serialPort.setSerialPortParams(9600,
				SerialPort.DATABITS_8,
				SerialPort.STOPBITS_1,
				SerialPort.PARITY_NONE);
			} catch (UnsupportedCommOperationException e)
			{
				return InitFail;
			}
		} catch (NoSuchPortException e)
			{
			return InitFail;
			}
// when successfully open the serial port, create a new serial buffer,
// then create a thread that consistently accepts incoming signals from
// the serial port. Incoming signals are stored in the serial buffer.
	SB = new SerialBuffer();
	RS = new ReadSerial(SB, in);
	RS.start();
// return success information
	return InitSuccess;
	}
/**
* This function returns a string with a certain length from the incomin
* @param Length The length of the string to be returned.
*/
	public String ReadPort()
	{
		String Msg;
		Msg = SB.GetMsg();
		return Msg;
	}
	public String ReadSearch()
	{
		String Msg;
		Msg = SB.GetSearch();
		return Msg;
	}
/**
* This function sends a message through the serial port.
* @param Msg The string to be sent.
*/
	public void WritePort(String Msg)
	{
		int c;
		try
		{
			for (int i = 0; i < Msg.length(); i++)
				out.write(Msg.charAt(i));
		} catch (IOException e) {}
	}
/* This function closes the serial port in use.
*/
	public void ClosePort()
	{	
		RS.stop();//warning:stop() in java.lang.Thread has been deprecated
		serialPort.close();
	}
}