Sending Custom objects over RMI

Question

I am new to RMI and am having trouble sending customised objects over an RMI connection - I am trying to send an object of class DataFile which implements serializable, to a method on the server called loadPerformanceData(DataFile data). Here is the class DataFile:
package org.twomey.fyp.loader;
import java.io.*;
import java.util.*;
import java.text.*;
import org.twomey.fyp.mail.*;
* Class to accept a File Object to prepare a File for Data Loading.
* It reads a Data File line-by-line and provides the functionality
* to insert line records into the database.
* @version 0.1
* @author Sean Twomey
public class DataFile implements Serializable{
/** Data Loading Date */
private String date;
/** Log from Loading Process */
private StringBuffer log;
/** Array of lines from file */
private String file[];
* Constructs a Data File from a specified File Object.
* Accepts the File object and Data Loading Date
* @param inputFile Inputted File Object
* @param date Data Loading Date
public DataFile(File inputFile, Calendar date){
     // Formats the date into a form acceptable to Oracle DBMS
     SimpleDateFormat form = new SimpleDateFormat("dd-MMM-yy");
     this.date = form.format(date.getTime());
     String line;
     int count = 0;
     try{
          RandomAccessFile inFile = new RandomAccessFile(inputFile, "r");
          // Read until end-of-file counting lines
          while((line = inFile.readLine()) != null){
               count++;
          // Initialise array size to number of lines.
          file = new String[count];
          // Return to start-of-file
          inFile.seek(0);
          for(int i=0;i < file.length;i++){
               // Read line into array
               file[i] = inFile.readLine();
          inFile.close();
     catch(IOException ie){
          System.err.println("IO Exception: " + ie);
* Load the entire set of records into the Database.
* Data is loaded line-by-line. A Data Record object
* is initilised to perform record loading and the
* insertRecord method is called for each record.
* A log is compiled from the insertion process
* @return The Process Log
public StringBuffer loadData(){
     String record[];
     log = new StringBuffer("");
     System.out.println("HERE");
     System.out.println(file.length);
     // From the org.twomey.fyp.loader package
     DataRecord objRecord;
     objRecord = new DataRecord(date);
     // Line-by-Line
     for(int i = 0; i < file.length; i++){
          // Split the record into fields which have been tab-delimited
          record = file.split("\t");
          // Each record feed must be 12 fields for valid loading
          if(record.length != 12){
               System.err.println("Invalid Feed for line " + (i+1));
               log.append("Invalid Feed for Line " + (i+1) + "\n");
          else{
               log.append("Line "+(i+1) + " " objRecord.insertRecord(record) "\n");
     return log;
* Send an EMail upon Completion the Performance Data Loading Process.
* The mail sents the log compiled during Data Loading.
public void sendMailReport(){
     // Use the Mail class from the org.twomey.mail package
     Mail email;
     String from;
     String alias;
     String to[];
     String subject;
     email = new Mail("chara.ucc.ie");
     to = getAddresses();
     from = System.getProperty("user.name") + "@chara.ucc.ie";
     alias = "Sheet Generator System";
     subject = "Performance Data Loader Report";
     email.sendEMail(from,alias,to,null,null,subject,log.toString());
* Returns Email addresses from file.
* The <b>mail.config</b> file is read line-by-line.
* Each line entry should correspond to an email address.
* @return Email addresses in a <CODE>String</CODE> array
private String[] getAddresses(){
     RandomAccessFile inFile;
String strLine;
String addresses[] = null;
     int count = 0;
try{
     inFile = new RandomAccessFile(new File("mail.config"),"r");
          while((strLine = inFile.readLine())!= null){
               count++;
          addresses = new String[count];
     inFile.seek(0);
          for(int i = 0; i < addresses.length; i++){
     addresses[i] = inFile.readLine();
catch(IOException ie){
     System.err.println("IOException: " + ie.getMessage());
return addresses;
} // end getAddresses
} // end Class

Answer 1

You seem to be reading the file into a string array, then trying to pass the object that did the reading.
Two alternatives:
o Just pass the string array object.
o Create a data only object, passing the string array as an argument to the constructor