如何用java读取电子称的RS232接口上的数据？

[roy103]

小弟是java新手，最近要做一个项目，就是要从RS232接口上读取电子称上的数据，然后打印成重量标签。
不知道怎么从RS232接口读取数据和调用打印机接口程序.
希望各位大哥指点，有这方面资料的，发到我邮箱：[e-mail] 谢谢！

[beck_716]

DTU

[zhanghua4109]

package serial;
import gnu.io.SerialPort;
import java.util.HashMap;
public class CommTest {

public static void main(String[] args) {
HashMap<String, Comparable> params = new HashMap<String, Comparable>();
params.put(SerialReader.PARAMS_PORT, "COM8"); // 端口名称
params.put(SerialReader.PARAMS_RATE, 9600); // 波特率
params.put(SerialReader.PARAMS_TIMEOUT, 1000); // 设备超时时间 1秒
params.put(SerialReader.PARAMS_DELAY, 200); // 端口数据准备时间 1秒
params.put(SerialReader.PARAMS_DATABITS, SerialPort.DATABITS_8); // 数据位
params.put(SerialReader.PARAMS_STOPBITS, SerialPort.STOPBITS_1); // 停止位
params.put(SerialReader.PARAMS_PARITY, SerialPort.PARITY_NONE); // 无奇偶校验
SerialReader sr = new SerialReader(params);
CommDataObserver bob = new CommDataObserver("bob");
CommDataObserver joe = new CommDataObserver("joe");
sr.addObserver(joe);
sr.addObserver(bob);
}
}

---------------- 2 -----------------
package 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.SerialPortEventListener;
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 java.util.Observable;
import java.util.TooManyListenersException;
/**
* 串口数据读取类,用于windows的串口数据读取
*
*/
public class SerialReader extends Observable implements Runnable, SerialPortEventListener {
static CommPortIdentifier portId;
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 SerialReader(HashMap params) {
serialParams = params;
init();
}
private void init() {
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());
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);
} catch (PortInUseException e) {
System.out.println("端口已经被占用!");
e.printStackTrace();
} catch (TooManyListenersException e) {
System.out.println("端口监听者过多!");
e.printStackTrace();
} catch (UnsupportedCommOperationException e) {
System.out.println("端口操作命令不支持!");
e.printStackTrace();
} catch (NoSuchPortException e) {
System.out.println("端口不存在!");
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Thread readThread = new Thread(this);
readThread.start();
}
/**
* Method declaration
*
*
* @see
*/
public void run() {
try {
Thread.sleep(100);
} 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);
System.out.print("serialEvent[" + event.getEventType() + "] ");
} 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
// while (inputStream.available() > 0) {
// numBytes = inputStream.read(readBuffer);
// }
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) {
setChanged();
byte[] temp = new byte[length];
System.arraycopy(message, 0, temp, 0, length);
// System.out.println("msg[" + numBytes + "]: [" + new String(temp) + "]");
notifyObservers(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 -----------------
package serial;
import java.util.Observable;
import java.util.Observer;
class CommDataObserver implements Observer {
String name;
public CommDataObserver(String name) {
this.name = name;
}
public void update(Observable o, Object arg) {
System.out.println("[" + name + "] GetMessage:\n [" + new String((byte[]) arg) + "]");
}
}

[roy103]

多谢大哥指点~~~

[roy103]

我的到了这样的结果：
serialEvent[1] [bob] GetMessage:
[+00035231C+00035231C+00035231C+00035231C]
[joe] GetMessage:
[+00035231C+00035231C+00035231C+00035231C]

数据是10位，是不是'+'代表起始位，'C'代表停止位，中间是数据位？
这是一连串数据，我要怎么样才能得到一个有效数据呢~~~

[roy103]

问题解决了，谢谢大哥指点~~

[随风q]

读取来的数据有乱码怎么解决！！！！！！！！！！！

[随风q]

请指点，我的QQ:497211079

[xu464383488]

为什么我按你们写的程序运行到 serialPort = (SerialPort) portId.open("SerialReader", timeout);就停止了也没报什么异常信息？