Duplicate of Implementation of Xmodem Protocol in Java
在Java中实现Xmodem协议的重复
I've got to implement the xmodem protocol to receive a file from a target device. For that, I have to request the file, then for every 128-byte packet received, I have to send an acknowledgment. My problem is when I open an outputstream to request the file, it will write but after that I can't write again to the outputstream. What is the problem I'm not getting?
我必须实现xmodem协议以从目标设备接收文件。为此,我必须请求文件,然后对于收到的每个128字节数据包,我必须发送一个确认。我的问题是当我打开一个输出流来请求文件时,它会写,但之后我不能再写入输出流。我没有得到什么问题?
package writeToPort;
import java.awt.Toolkit;
import java.io.*;
import java.util.*;
import javax.comm.*;
import javax.swing.JOptionPane;
import constants.Constants;
public class Flashwriter implements Runnable, SerialPortEventListener {
Enumeration portList;
CommPortIdentifier portId;
String messageString = "\r\nFLASH\r\n";
SerialPort serialPort;
OutputStream outputStream,outputStream2;
InputStream inputStream;
//Thread readThread;
String one, two;
String test = "ONLINE";
String[] dispArray = new String[1];
int i = 0;
Thread readThread;
byte[] readBufferArray;
int numBytes;
String response;
FileOutputStream out;
final int FLASH = 1, FILENAME = 2;
int number;
File winFile;
public static void main(String[] args) throws IOException {
Flashwriter sm = new Flashwriter();
sm.FlashWriteMethod();
}
public void FlashWriteMethod() throws IOException {
portList = CommPortIdentifier.getPortIdentifiers();
winFile = new File("D:\\testing\\out.FLS");
while (portList.hasMoreElements()) {
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
if (portId.getName().equals("COM2")) {
// if (portId.getName().equals("/dev/term/a")) {
try {
serialPort = (SerialPort) portId.open("SimpleWriteApp",
1000);
} catch (PortInUseException e) {
}
try {
outputStream = serialPort.getOutputStream();
inputStream = serialPort.getInputStream();
System.out.println(" Input Stream... " + inputStream);
} catch (IOException e) {
System.out.println("IO Exception");
}
try {
serialPort.addEventListener(this);
} catch (TooManyListenersException e) {
System.out.println("Tooo many Listener exception");
}
serialPort.notifyOnDataAvailable(true);
try {
serialPort.setSerialPortParams(9600,
SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
serialPort
.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
// serialPort.disableReceiveTimeout();
// outputStream.write(messageString.getBytes());
// sendRequest("/r/n26-02-08.FLS/r/n");
number = FLASH;
sendRequest(number);
} catch (UnsupportedCommOperationException e) {
}
}
}
}
}
public void serialEvent(SerialPortEvent event) {
SerialPort port = (SerialPort) event.getSource();
switch (event.getEventType()) {
case SerialPortEvent.DATA_AVAILABLE:
try {
while (inputStream.available() > 0) {
numBytes = inputStream.available();
readBufferArray = new byte[numBytes];
// int readtheBytes = (int) inputStream.skip(2);
int readBytes = inputStream.read(readBufferArray);
one = new String(readBufferArray);
System.out.println("readBytes " + one);
if (one.indexOf("FLASH_") > -1 & !(one.indexOf("FLASH_F") > -1)) {
System.out.println("got message");
response = "FLASH_OK";
// JOptionPane.showMessageDialog(null,
// "ONLINE",
// "Online Dump",
// JOptionPane.INFORMATION_MESSAGE);
// Toolkit.getDefaultToolkit().beep();
// outputStream.write("\r\nONLINEr\n".getBytes());
// outputStream.flush();
// outputStream.write("/r/n26-02-08.FLS/r/n".getBytes());
number = FILENAME;
sendRequest(number);
}
out = new FileOutputStream(winFile, true);
out.write(readBufferArray);
out.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
readBufferArray = null;
// break;
}
// try {
// int c;
// while((c = inputStream.read()) != -1) {
// out.write(c);
// }
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// // readBufferArray=null;
// break;
// }
// if (inputStream != null)
// try {
// inputStream.close();
// if (port != null) port.close();
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
//
//
readThread = new Thread(this);
readThread.start();
}
public void run() {
try {
System.out.println("In run() function ");
Thread.sleep(1000);
} catch (InterruptedException e) {
System.out.println("Interrupted Exception in run() method");
}
}
public void dispPacket(String packet) {
if (response == "FLASH_OK") {
System.out.println("disppacket " + packet);
} else {
System.out.println("No resust");
}
}
public void sendRequest(int num) {
switch (num) {
case FLASH:
try {
// outputStream = serialPort.getOutputStream();
outputStream.write("AT".getBytes());
// outputStream.write("\r\n26-02-08.FLS\r\n".getBytes());
System.out.println("Flash switch");
// outputStream.close();
outputStream.flush();
} catch (IOException e) {
e.printStackTrace();
}
break;
case FILENAME:
try {
//outputStream =(serialPort.getOutputStream());
outputStream.write("\r\nSUNSHINE\\06-03-09.FLS\r\n".getBytes());
System.out.println("File name");
outputStream.flush();
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
}
1 个解决方案
#1
Perhaps the streams are blocking.
也许流是阻塞的。
Java nio has channels that do not block. Try using one of those.
Java nio具有不阻塞的通道。尝试使用其中之一。
Here's a sample of reading a file with nio. I'm not sure if the same applies for you or not.
这是使用nio读取文件的示例。我不确定这是否适用于你。
I hope it helps.
我希望它有所帮助。
#1
Perhaps the streams are blocking.
也许流是阻塞的。
Java nio has channels that do not block. Try using one of those.
Java nio具有不阻塞的通道。尝试使用其中之一。
Here's a sample of reading a file with nio. I'm not sure if the same applies for you or not.
这是使用nio读取文件的示例。我不确定这是否适用于你。
I hope it helps.
我希望它有所帮助。