RXTX 读取 COM口
公司做的一个小系统需要连接托利多电子磅通过串口读取电子磅数据。
1 环境配置
将 rxtxSerial.dll、rxtx Parallel.dll 复制到jre安装目录bin下 例如 c:/Program Files/Java/jre1.6.0_01/bin/
将 XTXcomm.jar 复制到jre目录下的jre/ext目录下 例如 c:/Program Files/Java/jre1.6.0_01/lib/ext/
2 网上找的一个读取com类
package com.sailun.serial;
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.NoSuchPortException;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.UnsupportedCommOperationException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import com.sailun.bean.ComContent;
/**
* 串口数据读取类,用于windows的串口数据读取
*
*
* @author Lei Zhang
* @version 2012-6-14
*/
public class SerialReader {
static CommPortIdentifier portId;
public ComContent tempContent = new ComContent();
int delayRead = 200;
int numBytes; // buffer中的实际数据字节数
private static byte[] readBuffer = new byte[4096]; // 4k的buffer空间,缓存串口读入的数据
static Enumeration portList;
InputStream inputStream;
SerialPort serialPort;
HashMap serialParams;
// 端口读入数据事件触发后,等待n毫秒后再读取,以便让数据一次性读完
public static final String PARAMS_DELAY = "delay read"; // 延时等待端口数据准备的时间
public static final String PARAMS_TIMEOUT = "timeout"; // 超时时间
public static final String PARAMS_PORT = "port name"; // 端口名称
public static final String PARAMS_DATABITS = "data bits"; // 数据位
public static final String PARAMS_STOPBITS = "stop bits"; // 停止位
public static final String PARAMS_PARITY = "parity"; // 奇偶校验
public static final String PARAMS_RATE = "rate"; // 波特率
/**
* 初始化端口操作的参数.
*
*
* @see
*/
public ComContent getContetn() {
return this.tempContent;
}
public void setContent(String content) {
this.tempContent.setContent(content);
}
public void setTempContent(ComContent tempContent) {
this.tempContent = tempContent;
}
public SerialReader(HashMap params, ComContent content) {
serialParams = params;
init(content);
}
private void init(ComContent content) {
try {
// 参数初始化
int timeout = Integer.parseInt(serialParams.get(PARAMS_TIMEOUT)
.toString());
int rate = Integer.parseInt(serialParams.get(PARAMS_RATE)
.toString());
int dataBits = Integer.parseInt(serialParams.get(PARAMS_DATABITS)
.toString());
int stopBits = Integer.parseInt(serialParams.get(PARAMS_STOPBITS)
.toString());
int parity = Integer.parseInt(serialParams.get(PARAMS_PARITY)
.toString());
delayRead = Integer.parseInt(serialParams.get(PARAMS_DELAY)
.toString());
// System.out.println("参数初始化完成");
String port = serialParams.get(PARAMS_PORT).toString();
// 打开端口
portId = CommPortIdentifier.getPortIdentifier(port);
serialPort = (SerialPort) portId.open("SerialReader", timeout);
inputStream = serialPort.getInputStream();
// serialPort.addEventListener(this);
serialPort.notifyOnDataAvailable(true);
serialPort.setSerialPortParams(rate, dataBits, stopBits, parity);
try {
// 等待1秒钟让串口把数据全部接收后在处理
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
try {
numBytes = inputStream.read(readBuffer);
byte[] temp = new byte[numBytes];
System.arraycopy(readBuffer, 0, temp, 0, numBytes);
String temps = content.getContent() == null ? "" : content
.getContent();
content.setContent((temps + new String(temp)));
} catch (IOException e) {
e.printStackTrace();
}
} catch (PortInUseException e) {
content.setContent("电子磅端口已经被占用,请关闭使用电子磅的程式重试!");
e.printStackTrace();
} catch (UnsupportedCommOperationException e) {
//content.setContent("端口操作命令不支持!");
e.printStackTrace();
} catch (NoSuchPortException e) {
content.setContent("程序设置的电子磅端口不存在!");
e.printStackTrace();
} catch (IOException e) {
content.setContent("程序执行中遇到错误!" + e);
e.printStackTrace();
} finally {
try {
inputStream.close();
} catch (IOException e1) {
content.setContent("关闭输入流时异常出现：" + e1.getMessage());
}
try {
serialPort.close();
} catch (Exception e) {
content.setContent("关闭端口时异常出现：" + e.getMessage());
}
}
}
/**
* Method declaration
*
*
* @see
*/
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
}
/**
* Method declaration
*
*
* @param event
*
* @see
*/
public void serialEvent(SerialPortEvent event) {
try {
// 等待1秒钟让串口把数据全部接收后在处理
Thread.sleep(delayRead);
} catch (InterruptedException e) {
e.printStackTrace();
}
switch (event.getEventType()) {
case SerialPortEvent.BI: // 10
case SerialPortEvent.OE: // 7
case SerialPortEvent.FE: // 9
case SerialPortEvent.PE: // 8
case SerialPortEvent.CD: // 6
case SerialPortEvent.CTS: // 3
case SerialPortEvent.DSR: // 4
case SerialPortEvent.RI: // 5
case SerialPortEvent.OUTPUT_BUFFER_EMPTY: // 2
break;
case SerialPortEvent.DATA_AVAILABLE: // 1
try {
// 多次读取,将所有数据读入
numBytes = inputStream.read(readBuffer);
changeMessage(readBuffer, numBytes);
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
// 通过observer pattern将收到的数据发送给observer
// 将buffer中的空字节删除后再发送更新消息,通知观察者
public void changeMessage(byte[] message, int length) {
byte[] temp = new byte[length];
System.arraycopy(message, 0, temp, 0, length);
System.out.println("msg[" + numBytes + "]: [" + new String(temp) + "]");
}
static void listPorts() {
Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();
while (portEnum.hasMoreElements()) {
CommPortIdentifier portIdentifier = (CommPortIdentifier) portEnum
.nextElement();
System.out.println(portIdentifier.getName() + " - "
+ getPortTypeName(portIdentifier.getPortType()));
}
}
static String getPortTypeName(int portType) {
switch (portType) {
case CommPortIdentifier.PORT_I2C:
return "I2C";
case CommPortIdentifier.PORT_PARALLEL:
return "Parallel";
case CommPortIdentifier.PORT_RAW:
return "Raw";
case CommPortIdentifier.PORT_RS485:
return "RS485";
case CommPortIdentifier.PORT_SERIAL:
return "Serial";
default:
return "unknown type";
}
}
/**
* @return A HashSet containing the CommPortIdentifier for all serial ports
* that are not currently being used.
*/
public static HashSet<CommPortIdentifier> getAvailableSerialPorts() {
HashSet<CommPortIdentifier> h = new HashSet<CommPortIdentifier>();
Enumeration thePorts = CommPortIdentifier.getPortIdentifiers();
while (thePorts.hasMoreElements()) {
CommPortIdentifier com = (CommPortIdentifier) thePorts
.nextElement();
switch (com.getPortType()) {
case CommPortIdentifier.PORT_SERIAL:
try {
CommPort thePort = com.open("CommUtil", 50);
thePort.close();
h.add(com);
} catch (PortInUseException e) {
System.out.println("Port, " + com.getName()
+ ", is in use.");
} catch (Exception e) {
System.out.println("Failed to open port " + com.getName()
+ e);
}
}
}
return h;
}
}
3 在一个TimerTask中设置每秒读取一次
public class MyTimerTask2 extends TimerTask {
@Override
public void run() {
while (true) {
paramsWeight.put(SerialReader.PARAMS_PORT, com2); // 端口名称
paramsWeight.put(SerialReader.PARAMS_RATE, InitProperties
.getProperty("WeighterRate")); // 波特率 paramsWeight.put(SerialReader.PARAMS_TIMEOUT, InitProperties
.getProperty("WeighterRate")); // 设备超时时间 1秒
paramsWeight.put(SerialReader.PARAMS_DELAY, InitProperties
.getProperty("WeighterRate")); // 端口数据准备时间 1秒
paramsWeight.put(SerialReader.PARAMS_DATABITS,
SerialPort.DATABITS_7); // 数据位
paramsWeight.put(SerialReader.PARAMS_STOPBITS,
SerialPort.STOPBITS_1); // 停止位
paramsWeight.put(SerialReader.PARAMS_PARITY,
SerialPort.PARITY_EVEN); // 偶校验
new SerialReader(paramsWeight, contentWeight);
String sb = contentWeight.getContent();
int weight = -1;
if (!sb.equals("")) {
if (sb.startsWith("电子磅端口已经被占用")
|| sb.startsWith("端口操作命令不支持")
|| sb.startsWith("程序设置的电子磅端口不存在")
|| sb.startsWith("程序执行中遇到错误")
|| sb.startsWith("关闭输入流时异常出现")
|| sb.startsWith("关闭端口时异常出现")) {
message2.setText(sb);
message2.setForeground(Color.red);
int end1 = sb.lastIndexOf("");
if (end1 > 18) {
weight = Integer.parseInt(sb.substring(end1 - 14,
end1 - 7).replaceAll(" ", ""));// 起始位去掉
}
on_time_weight_val.setText(weight + " KG");
} else {
int end = sb.lastIndexOf("");
if (end > 18) {
weight = Integer.parseInt(sb.substring(end - 14,
end - 7).replaceAll(" ", ""));// 起始位去掉
}
on_time_weight_val.setText(weight + " KG");
}
} else {
on_time_weight_val.setText("没有读到电子磅数据");
}
}
}
}
4 这样就ok了，需要注意的是，在电子磅中系统接口-->COM口设置中的波特率、数据位、停止位、校验位要和程式中设置一样，否则会出现读取数据乱码和数据丢失等问题，如果执行读取类时报端口找不到则可能为读取com口环境配置有误。