serialbuffer.java

用java实现串口通信 用java实现串口通信

package communication;
/**
* This class implements the buffer area to store incoming data from the serial
* port.
*/
public class SerialBuffer
{
	private String Content = "";
	private String CurrentMsg, TempContent;
	private boolean available = false;
	private int LengthNeeded = 1;
/**
* This function returns a string with a certain length from the incomin
* messages.
* @param Length The length of the string to be returned.读取length个字符 赋给Msg
*/
	public synchronized String GetMsg(int Length)
	{
		LengthNeeded = Length;
		if (LengthNeeded > Content.length())
		{
			available = false;
			while (available == false)
			{
				try
				{
					wait();
				} catch (InterruptedException e) {System.out.println("SerialBuffer.GetMsg() is waiting"); }
			}
		}
		CurrentMsg = Content.substring(0, LengthNeeded);
	TempContent = Content.substring(LengthNeeded);
	//str＝str.substring(int beginIndex);截取掉str从首字母起长度为beginIndex的字符串，将剩余字符串赋值给str；
	//str＝str.substring(int beginIndex，int endIndex);截取str中从beginIndex开始至endIndex结束时的字符串，并将其赋值给str;

	Content = TempContent;
	LengthNeeded = 1;
	notifyAll();
	return CurrentMsg;
	}
/**
* This function stores a character captured from the serial port to the
* buffer area.
* @param t The char value of the character to be stored.
*/
	public synchronized void PutChar(int c)
	{
		Character d = new Character((char) c);
		Content = Content.concat(d.toString());
		if (LengthNeeded < Content.length())
	{
	available = true;//修改available，V，P标志（操作系统，控制并发）
	}
	notifyAll();
	}
}