解决Java Modbus代码问题

Question

我目前正在关注本指南：http://jamod.sourceforge.net/kb/serial_master_howto.html

尝试与串行设备实现modbus通信。我正在使用Spring Tool Suite。请注意我是一名业余程序员。

代码：

   package Test1;

 import java.net.*;
 import java.io.*;
 import net.wimpi.modbus.*;
 import net.wimpi.modbus.msg.*;
 import net.wimpi.modbus.io.*;
 import net.wimpi.modbus.net.*;
 import net.wimpi.modbus.util.*;

  public class JaMod {

   public static void main(String[] args) {
     try { /* The important instances of the classes mentioned before */
        SerialConnection con = null; //the connection
    ModbusSerialTransaction trans = null; //the transaction
    ReadInputRegistersRequest req = null; //the request
    ReadInputRegistersResponse res = null; //the response

    /* Variables for storing the parameters */
    String portname= "seven"; //the name of the serial port to be used
    int unitid = 9; //the unit identifier we will be talking to
    int ref = 1000; //the reference, where to start reading from
    int count = 5; //the count of IR's to read
    int repeat = 5; //a loop for repeating the transaction


    //2. Set master identifier
    //ModbusCoupler.createModbusCoupler(null);
    ModbusCoupler.getReference().setUnitID(1);      

    //3. Setup serial parameters
    SerialParameters params = new SerialParameters();
    params.setPortName(portname);
    params.setBaudRate(19200);
    params.setDatabits(8);
    params.setParity("None");
    params.setStopbits(1);
    params.setEncoding("ascii");
    params.setEcho(false);

    //4. Open the connection
    con = new SerialConnection(params);
    con.open();

    //5. Prepare a request
    req = new ReadInputRegistersRequest(ref, count);
    req.setUnitID(unitid);
    req.setHeadless();

    //6. Prepare a transaction
    trans = new ModbusSerialTransaction(con);
    trans.setRequest(req);

    //7. Execute the transaction repeat times
    int k = 0;
    do {
      trans.execute();
      res = (ReadInputRegistersResponse) trans.getResponse();
      for (int n = 0; n < res.getWordCount(); n++) {
        System.out.println("Word " + n + "=" + res.getRegisterValue(n));
      }
      k++;
    } while (k < repeat);

    //8. Close the connection
    con.close();  

} catch (Exception ex) {
  ex.printStackTrace();
}
}//main

  }//class SerialAITest

Imported Libraries

尽管看似直截了当，但我收到了这个警告： - 导入Java.net 和 - 导入java.io

从未使用过。我不确定自己做错了什么..