javacomm64位用不了，可以使用RXTXcomm for x64

安装完后把导入包名改一下就行了！

附上读串口代码：

/*
* @(#)SimpleRead.java 1.12 98/06/25 SMI
*
* Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license
* to use, modify and redistribute this software in source and binary
* code form, provided that i) this copyright notice and license appear
* on all copies of the software; and ii) Licensee does not utilize the
* software in a manner which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind.
* ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
* INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND
* ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
* LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE
* SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS
* BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES,
* HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING
* OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control
* of aircraft, air traffic, aircraft navigation or aircraft
* communications; or in the design, construction, operation or
* maintenance of any nuclear facility. Licensee represents and
* warrants that it will not use or redistribute the Software for such
* purposes.
*/

import java.io.*;
import java.util.*;
import gnu.io.*;

public class SimpleRead implements Runnable, SerialPortEventListener {
static CommPortIdentifier portId;
static Enumeration portList;

InputStream inputStream;
SerialPort serialPort;
Thread readThread;

public static void main(String[] args) {
portList = CommPortIdentifier.getPortIdentifiers();

while (portList.hasMoreElements()) {

portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {

// if (portId.getName().equals("COM1")) {
if (portId.getName().equals("COM8")) {
SimpleRead reader = new SimpleRead();

}
}
}
}

public SimpleRead() {
try {
serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);
} catch (PortInUseException e) {}
try {
inputStream = serialPort.getInputStream();
} catch (IOException e) {}
try {
serialPort.addEventListener(this);
} catch (TooManyListenersException e) {}
serialPort.notifyOnDataAvailable(true);
try {
serialPort.setSerialPortParams(9600,
SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
} catch (UnsupportedCommOperationException e) {}
readThread = new Thread(this);
readThread.start();
}

public void run() {
try {
Thread.sleep(20000);
} catch (InterruptedException e) {}
}

public void serialEvent(SerialPortEvent event) {
switch(event.getEventType()) {
case SerialPortEvent.BI:
case SerialPortEvent.OE:
case SerialPortEvent.FE:
case SerialPortEvent.PE:
case SerialPortEvent.CD:
case SerialPortEvent.CTS:
case SerialPortEvent.DSR:
case SerialPortEvent.RI:
case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
break;
case SerialPortEvent.DATA_AVAILABLE:
byte[] readBuffer = new byte[20];

try {
while (inputStream.available() > 0) {
int numBytes = inputStream.read(readBuffer);
}
System.out.print(new String(readBuffer));
} catch (IOException e) {}
break;
}
}
}