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| 使用Java读取串口的程序 |
作者：未知
文章来源：www.jspcn.net
访问次数：429次
加入时间：2005年01月19日
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下是我写的用Java读取串口的程序。这个程序里面还有一些问题，也希望有经验的网友能够给我提点意见。
这个简单的程序包括以下文件：
IMU.java (主程序)
ReadBuffer.java (从缓冲区读取一个消息)
ReadSerial.java (读取串口数据并放入缓冲区)
SerialBuffer.java (缓冲区)
WriteSerial.java (不断的往串口送星号´*´)
测试程序：
SendCom.java (将一个数据文件往串口发送)
SEND.TXT (供测试用的数据文件)
在这个通讯程序中使用了一个简单的协议，既不同的消息之间用星号´*´作为分隔。这个程序中的问题是ReadSerial进程和WriteSerial进程不能够同时启动，出错信息是不能够打开串口，因为同样一个串口不能够同时被打开两次(在ReadSerial中声明了FileReader
测试程序：
SendCom.java (将一个数据文件往串口发送)
SEND.TXT (供测试用的数据文件)
在这个通讯程序中使用了一个简单的协议，既不同的消息之间用星号´*´作为分隔。这个程序中的问题是ReadSerial进程和WriteSerial进程不能够同时启动，出错信息是不能够打开串口，因为同样一个串口不能够同时被打开两次(在ReadSerial中声明了FileReader和在WriteSerial中声明了FileWriter)。这样是不能够实现全双工通讯的。
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import java.io.*;
class IMU
{
public static void main(String[] args)
{
//TO DO: Add your JAVA codes here
File ComPort = new File("COM1");
SerialBuffer SB = new SerialBuffer();
ReadSerial r1 = new ReadSerial(SB, ComPort);
ReadBuffer r2 = new ReadBuffer(SB);
WriteSerial r3 = new WriteSerial(ComPort);
r1.start();
r2.start();
r3.start();
}
}
---------------------------------------------
import java.io.*;
public class ReadBuffer extends Thread
{
private SerialBuffer ComBuffer;
public ReadBuffer(SerialBuffer SB)
{
ComBuffer = SB;
}
public void run()
{
String Msg;
while (true)
{
Msg = ComBuffer.GetMsg();
System.out.println(Msg);
}
}
}
-----------------------------------------------
import java.io.*;
public class ReadSerial extends Thread
{
private SerialBuffer ComBuffer;
private File ComPort;
public ReadSerial(SerialBuffer SB, File Port)
{
ComBuffer = SB;
ComPort = Port;
}
public void run()
{
int c;
try
{
FileReader in = new FileReader(ComPort);
while (true)
{
c = in.read();
ComBuffer.PutChar(c);
}
try
{
FileReader in = new FileReader(ComPort);
while (true)
{
c = in.read();
ComBuffer.PutChar(c);
}
} catch (IOException e) {}
}
}
------------------------------------------------
public class SerialBuffer
{
private String Content = "";
private String CurrentMsg, TempContent;
private boolean available = false;
public synchronized String GetMsg()
{
int SepMark;
if ((SepMark = Content.indexOf(´*´)) == -1)
{
available = false;
while (available == false)
{
try
{
wait();
} catch (InterruptedException e) { }
}
SepMark = Content.indexOf(´*´);
}
CurrentMsg = Content.substring(0, SepMark);
TempContent = Content.substring(SepMark+1);
Content = TempContent;
notifyAll();
return CurrentMsg;
}
public synchronized void PutChar(int c)
{
Character d = new Character((char) c);
Content = Content.concat(d.toString());
if (c == ´*´)
{
available = true;
}
notifyAll();
}
}
-------------------------------------------------
import java.io.*;
public class WriteSerial extends Thread
{
private SerialBuffer ComBuffer;
private File ComPort;
public WriteSerial(File Port)
{
ComPort = Port;
}
public void run()
{
int c;
try
{
FileWriter out = new FileWriter(ComPort);
while (true)
{
out.write(´*´);
}
} catch (IOException e)
{
System.out.println(e.getMessage());
}
}
}
-----------------------------------------------
import java.io.*;
public class SendCom
{
public static void main(String[] args)
{
File OutFile = new File("SEND.TXT");
File ComPort = new File("COM2");
int c;
try
{
FileReader in = new FileReader(OutFile);
FileWriter out = new FileWriter(ComPort);
while ((c = in.read()) != -1)
out.write(c);
in.close();
out.close();
} catch (IOException e) {}
}
}
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SEND.TXT*
This is a sample of the data file for program testing. *
It should be in the same directory as the SendCom.class file.*
When you run this sample program, connect your COM1 and COM2 with a
serial cable so that you can test this program on one machine. If
you have two machines, you can connect the two machine via a serial
cable and test it. Modified the definition of ComPort in the program
if necessary. *
Thank you for testing this program. If you have any suggestions please
kindly let me know. *
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