travel agent - java writing to file via user input

[Abhradeep Banerjee]

1)getting error at line 78 lab6Ex1
2) how do i delete a record via user input eg. if user wants to delete record 0 the user will enter the number 0 and it will delete 0

i know its LL.remove();
im not sure what to put inside the bracket

   
import java.io.*;
import java.util.*;
import java.util.StringTokenizer;



public class lab6Ex1 {

    public static void main(String[] args) {


        Travel tr;
        //declare variables FileReader, bufferedReader & inFile and line
        FileReader fr = null;
        BufferedReader br = null;
        String inFile = "Travel_Records.txt";
        String line = "";


        //declare variables for Menus Input_prompt, IC_Prompt,etc
        final String INPUT_PROMPT1 = "\nPlease select one of the following options: \n"
                + "1)	Search flights by IC number \n"
                + "2)	Search flights by departure date \n"
                + "3)	Display all flights \n"
                + "4)	Insert new record or remove old record \n"
                + "5)	Exit program ";

        final String IC_PROMPT = "\n\n\nPlease enter the IC number";
        final String Dept_PROMPT = "\n\n\nPlease enter the departure date in the following format" + "dd/mm/yyyy";
        final String Insert_Remove_PROMPT = "\n\n\n \n"
                + "1) Remove Record\n"
                + "2) Insert Record\n"
                + "3) Return to previous menu\n"
                + "4) Exit Program";

        final String Insert_Record = "Please enter new record in the following format: Serial Number|SXXXXXXXG|Name | Country |MM/DD/YYYY | Time in 24 hr clock | Country | MM/DD/YYYY | Time in 24 hr clock";
        final String Delete_Record = "Please enter the serial number of the record to delete";
        //declare var to contain the record files


        int index;
        String NRIC;
        String Name;
        String srcCountry;
        String deptDate;
        String deptTime;
        String destCountry;
        String arrDate;
        String arrTime;


        //delare and initiate new linked list

        LinkedList<Travel> LL = new LinkedList<Travel>();




        try {

            //initiate filereader and bufferedreader objects

            fr = new FileReader(inFile);
            br = new BufferedReader(fr);



            //read 1 line from the file
            line = br.readLine();

            // while line is not null

            while (line != null) {

                StringTokenizer tokenizer = new StringTokenizer(line, "|");
                index = Integer.parseInt(tokenizer.nextToken());
                NRIC = tokenizer.nextToken();
                Name = tokenizer.nextToken();
                srcCountry = tokenizer.nextToken();
                deptDate = tokenizer.nextToken();
                deptTime = tokenizer.nextToken();
                destCountry = tokenizer.nextToken();
                arrDate = tokenizer.nextToken();
                arrTime = tokenizer.nextToken();
                //create new Travel object
                Travel travel = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);

                //add this item object to Llist
                LL.addFirst(travel);

                //read another line from file
                line = br.readLine();

            }
            //close buffered reader
            br.close();
        } catch (FileNotFoundException e) {
            System.out.println("The file" + inFile + "was not found");
        } catch (IOException e) {
            System.out.println("Reading error");
        } finally {
            //close filereader
            if (fr != null) {
                try {
                    fr.close();
                } catch (IOException e) {
                    System.out.println("error closing file");
                }

            }

        }
        //create readers to read from user input
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            System.out.println(INPUT_PROMPT1);
            //read one line from user
            line = reader.readLine();

            while (!line.equals("0")) {


                //read one line from user
                Collections.sort(LL);

                if (line.equals("1")) {
                    System.out.println(IC_PROMPT);

                    BufferedReader IC = new BufferedReader(new InputStreamReader(System.in));
                    line = IC.readLine();
                    for (int n = 0; n < LL.size(); n++) {

                        if (LL.get(n).NRIC.toUpperCase().contains(line.toUpperCase())) {

                            //printout information of the video
                            System.out.println(LL.get(n));

                        }
                    }
                } else if (line.equals("2")) {

                    System.out.println(Dept_PROMPT);
                    BufferedReader Dept = new BufferedReader(new InputStreamReader(System.in));
                    line = Dept.readLine();
                    for (int n = 0; n < LL.size(); n++) {

                        if (LL.get(n).deptDate.toUpperCase().contains(line.toUpperCase())) {

                            //printout information of the video
                            System.out.println(LL.get(n));
                        } else {
                            System.out.println("No such record");

                        }
                    }
                } else if (line.equals("3")) {
                    for (int n = 0; n < LL.size(); n++) {
                        System.out.println(LL.get(n));
                    }

                } else if (line.equals("4")) {
                    System.out.println(Insert_Remove_PROMPT);
                    BufferedReader Insert = new BufferedReader(new InputStreamReader(System.in));
                    line = Insert.readLine();




                    if (line.equals("1")) {
                        System.out.println(Delete_Record);

                    } else if (line.equals("2")) {
                        System.out.println(Insert_Record);

                        try {
                            BufferedReader insert = new BufferedReader(new InputStreamReader(System.in));
                            line = insert.readLine();
                            System.out.println("Travel record is" + line);

                            StringTokenizer insertrecord = new StringTokenizer(line, "|");

                            System.out.println("serial number: " + insertrecord.nextToken());
                            System.out.println("NRIC Number: " + insertrecord.nextToken());
                            System.out.println("Source Country " + insertrecord.nextToken());
                            System.out.println("Departure Date: " + insertrecord.nextToken());
                            System.out.println("Departure Time: " + insertrecord.nextToken());
                            System.out.println("Destination Country: " + insertrecord.nextToken());
                            System.out.println("Arrival Date: " + insertrecord.nextToken());
                            System.out.println("Arrival Time: " + insertrecord.nextToken());


                            FileWriter fwp = new FileWriter(inFile);
                            BufferedWriter bwp = new BufferedWriter(fwp);
                            PrintWriter outFile_pass = new PrintWriter(bwp);

                            while (line != null) {
                                StringTokenizer tokenizer = new StringTokenizer(line, "|");
                                index = Integer.parseInt(tokenizer.nextToken());
                                NRIC = tokenizer.nextToken();
                                Name = tokenizer.nextToken();
                                srcCountry = tokenizer.nextToken();
                                deptDate = tokenizer.nextToken();
                                deptTime = tokenizer.nextToken();
                                destCountry = tokenizer.nextToken();
                                arrDate = tokenizer.nextToken();
                                arrTime = tokenizer.nextToken();

                                tr = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);

                                System.out.println(tr);
                                outFile_pass.println(tr);
                                line = insert.readLine();


                            }
                            outFile_pass.close();




                        } catch (Exception e) {
                            System.out.println("Input error!");
                        }

                    } else if (line.equals("3")) {
                    } else if (line.equals("4")) {

                        System.out.println("Are you sure you want to exit? Y/N");
                        BufferedReader exit = new BufferedReader(new InputStreamReader(System.in));
                        line = exit.readLine();
                        if (line.equalsIgnoreCase("Y")) {
                            System.exit(0);

                        }

                    }



                } else if (line.equals("5")) {
                    System.out.println("Are you sure you want to exit? Y/N");
                    BufferedReader exit = new BufferedReader(new InputStreamReader(System.in));
                    line = exit.readLine();
                    if (line.equalsIgnoreCase("Y")) {
                        System.exit(0);

                    }
                } else {
                    System.out.println("Wrong entry");

                }
                System.out.println(INPUT_PROMPT1);
                line = reader.readLine();
            }
        } catch (IOException e) {
            System.out.println("error");
        }
    }
}


 

Travel.java

   
public class Travel implements Comparable<Travel>  {

    // declare all var to contain the fields of a record

     int index;
     String NRIC;
     String Name;
     String srcCountry;
     String deptDate;
     String deptTime;
     String destCountry;
     String arrDate;
     String arrTime;

    //creates constructor to store all the fields into the var

    public Travel(int index, String NRIC, String Name, String srcCountry, String deptDate, String deptTime, String destCountry, String arrDate, String arrTime)
    {
        this.index = index;
        this.NRIC = NRIC;
        this.Name = Name;
        this.srcCountry = srcCountry;
        this.deptDate = deptDate;
        this.deptTime = deptTime;
        this.destCountry = destCountry;
        this.arrDate = arrDate;
        this.arrTime = arrTime;
        // create  a toString () method to return sting in the same delimited
        //format as input record
    }
        public String toString(){
            return(index+ "|" + NRIC + "|" + Name + "|" + srcCountry + "|" +deptDate + "|" +deptTime + "|" +destCountry + "|" + arrDate + "|" + arrTime );
        }
public int compareTo(Travel LL){
    return new Integer(index).compareTo(new Integer(LL.index));
}
        
    }


 

[Hunter McMillen]

Abhradeep Banerjee wrote:
1)getting error at line 78 lab6Ex1

What error are you getting exactly?

Abhradeep Banerjee wrote:
2) how do i delete a record via user input eg. if user wants to delete record 0 the user will enter the number 0 and it will delete 0

i know its LL.remove();
im not sure what to put inside the bracket

You are using a linkedlist so elements in the list arent indexed with numbers like an array. You would have to write your own function to go n elements into the list and remove that element.

[Abhradeep Banerjee]

1) yes i know its not in array but if im not wrong you can just use the remove command and delete the record via index which Ihave declared


2)

Exception in thread "main" java.util.NoSuchElementException
at java.util.StringTokenizer.nextToken(StringTokenizer.java:332)
at lab6Ex1.main(lab6Ex1.java:78)
Java Result: 1

[Hunter McMillen]

Ok so the error you are getting if from calling nextToken() the NoSuchElementException comes from not having anything in the Tokenizer. You can't get the next token of an empty tokenizer. So I would print out your line variable to check to see if what you think is there, is actually there.

You are correct about the remove function , I didn't know it had that capability.

Hunter

[Abhradeep Banerjee]

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOfRange(Arrays.java:3209)
at java.lang.String.<init>(String.java:215)
at java.io.BufferedReader.readLine(BufferedReader.java:331)
at java.io.BufferedReader.readLine(BufferedReader.java:362)
at lab6Ex1.main(lab6Ex1.java:91)
Java Result: 1
BUILD SUCCESSFUL (total time: 14 seconds)

getting this error now

[Abhradeep Banerjee]

im getting a out of memory heap error now all of a sudden anyone know the problem??

[pete stein]

Please show what your code now looks like and which line (mark with an obvious comment such as // !!! error here !!!) causes the exception. I see one while loop where you check to see if line is null but you don't appear to ever change the state of the line variable.

[Abhradeep Banerjee]

    


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

public class lab6Ex1 {

    public static void main(String[] args) {

        //declare var
        FileReader fr = null;
        BufferedReader br = null;
        String inFile = "Travel_Records.txt";
        String line = "";
        final String INPUT_PROMPT1 = "\nPlease select one of the following options: \n"
                + "1)	Search flights by IC number \n"
                + "2)	Search flights by departure date \n"
                + "3)	Display all flights \n"
                + "4)	Insert new record or remove old record \n"
                + "5)	Exit program ";

        final String IC_PROMPT = "\n\n\nPlease enter the IC number";
        final String Dept_PROMPT = "\n\n\nPlease enter the departure date in the following format" + "dd/mm/yyyy";
        final String Insert_Remove_PROMPT = "\n\n\n \n"
                + "1) Remove Record\n"
                + "2) Insert Record\n"
                + "3) Return to previous menu\n"
                + "4) Exit Program";

        final String Insert_Record = "Please enter new record in the following format: Serial Number|SXXXXXXXG|Name | Country |MM/DD/YYYY | Time in 24 hr clock | Country | MM/DD/YYYY | Time in 24 hr clock";
        final String Delete_Record = "Please enter the serial number of the record to delete";
        //declare var to contain the record files


        int index;
        String NRIC;
        String Name;
        String srcCountry;
        String deptDate;
        String deptTime;
        String destCountry;
        String arrDate;
        String arrTime;


        //delare and initiate new linked list

        LinkedList<Travel> LL = new LinkedList<Travel>();


        try {

            //initiate filereader and bufferedreader objects

            fr = new FileReader(inFile);
            br = new BufferedReader(fr);

            //read 1 line from the file
            line = br.readLine();

            // while line is not null

            while (line != null) {
                StringTokenizer tokenizer = new StringTokenizer(line, "|");
                index = Integer.parseInt(tokenizer.nextToken());
                NRIC = tokenizer.nextToken();
                Name = tokenizer.nextToken();
                srcCountry = tokenizer.nextToken();
                deptDate = tokenizer.nextToken();
                deptTime = tokenizer.nextToken();
                destCountry = tokenizer.nextToken();
                arrDate = tokenizer.nextToken();
                arrTime = tokenizer.nextToken();
                //create new Travel object
                Travel travel = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);

                //add this item object to Llist
                LL.addFirst(travel);

                //read another line from file
                line = br.readLine(); <=== over here is the error for outof memory heap error

            }
            //close buffered reader
            br.close();
        } catch (FileNotFoundException e) {
            System.out.println("The file" + inFile + "was not found");
        } catch (IOException e) {
            System.out.println("Reading error");
        } finally {
            //close filereader
            if (fr != null) {
                try {
                    fr.close();
                } catch (IOException e) {
                    System.out.println("error closing file");
                }
                //print out the input prompt



            }

        }



        //create readers to read from user input
        try {


            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

            //read one line from user

            System.out.println(INPUT_PROMPT1);

            line = reader.readLine();

            while (!line.equals("0")) {

                //read one line from user


                if (line.equals("1")) {
                    System.out.println(IC_PROMPT);

                    BufferedReader IC = new BufferedReader(new InputStreamReader(System.in));
                    line = IC.readLine();
                    for (int n = 0; n < LL.size(); n++) {

                        if (LL.get(n).NRIC.toUpperCase().contains(line.toUpperCase())) {

                            //printout information of the video
                            System.out.println(LL.get(n));

                        }
                    }
                } else if (line.equals("2")) {

                    System.out.println(Dept_PROMPT);
                    BufferedReader Dept = new BufferedReader(new InputStreamReader(System.in));
                    line = Dept.readLine();
                    for (int n = 0; n < LL.size(); n++) {

                        if (LL.get(n).deptDate.toUpperCase().contains(line.toUpperCase())) {

                            //printout information of the video
                            System.out.println(LL.get(n));
                        } else {
                            System.out.println("No such record");

                        }
                    }
                } else if (line.equals("3")) {
                    for (int n = 0; n < LL.size(); n++) {
                        System.out.println(LL.get(n));
                    }
                } else if (line.equals("4")) {
                    System.out.println(Insert_Remove_PROMPT);
                    BufferedReader Insert = new BufferedReader(new InputStreamReader(System.in));
                    line = Insert.readLine();

                    if (line.equals("1")) {
                        System.out.println(Delete_Record);
                        //   LL.remove(line.equals(int index));

                    } else if (line.equals("2")) {
                        System.out.println(Insert_Record);



                        StringTokenizer tokenizer = new StringTokenizer(line, "|");
                        index = Integer.parseInt(tokenizer.nextToken());
                        NRIC = tokenizer.nextToken();
                        Name = tokenizer.nextToken();
                        srcCountry = tokenizer.nextToken();
                        deptDate = tokenizer.nextToken();
                        deptTime = tokenizer.nextToken();
                        destCountry = tokenizer.nextToken();
                        arrDate = tokenizer.nextToken();
                        arrTime = tokenizer.nextToken();
                        //create new Travel object
                        Travel travel = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);

                        //add this item object to Llist
                        LL.addFirst(travel);

                    } else if (line.equals("3")) {
                        System.out.println("");

                    } else if (line.equals("5")) {
                        System.out.println("Are you sure you want to exit? Y/N");
                        BufferedReader exit = new BufferedReader(new InputStreamReader(System.in));
                        line = exit.readLine();
                        if (line.equalsIgnoreCase("Y")) {
                            System.exit(0);

                        }
                    }
                }

                System.out.println(INPUT_PROMPT1);
                line = reader.readLine();
            }
        } catch (IOException e) {
            System.out.println("error");
        }
    }
}

[pete stein]

One more request -- can you post a data file?

[Abhradeep Banerjee]

i found the problem the code for insert had a problem instead of adding just 1ce it added it multiple times

[Abhradeep Banerjee]

             while (line != null) {

                 StringTokenizer tokenizer = new StringTokenizer(line, "|");
                 index = Integer.parseInt(tokenizer.nextToken()); <== getting a no element error over here

                 NRIC = tokenizer.nextToken();
                 Name = tokenizer.nextToken();
                 srcCountry = tokenizer.nextToken();
                 deptDate = tokenizer.nextToken();
                 deptTime = tokenizer.nextToken();
                 destCountry = tokenizer.nextToken();
                 arrDate = tokenizer.nextToken();
                 arrTime = tokenizer.nextToken();
                 //create new Travel object
                 Travel travel = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);

                 //add this item object to Llist
                 LL.addFirst(travel);

                 //read another line from file
                 line = br.readLine();

             }    

[pete stein]

Abhradeep Banerjee wrote:i found the problem the code for insert had a problem instead of adding just 1ce it added it multiple times

Good deal -- congratulations!

[Abhradeep Banerjee]

im getting a no element error now...

  #
# import java.io.*;  
# import java.util.*;  
#   
# public class lab6Ex1 {  
#   
#     public static void main(String[] args) {  
#   
#         //declare var  
#         FileReader fr = null;  
#         BufferedReader br = null;  
#         String inFile = "Travel_Records.txt";  
#         String line = "";  
#         final String INPUT_PROMPT1 = "\nPlease select one of the following options: \n"  
#                 + "1)   Search flights by IC number \n"  
#                 + "2)   Search flights by departure date \n"  
#                 + "3)   Display all flights \n"  
#                 + "4)   Insert new record or remove old record \n"  
#                 + "5)   Exit program ";  
#   
#         final String IC_PROMPT = "\n\n\nPlease enter the IC number";  
#         final String Dept_PROMPT = "\n\n\nPlease enter the departure date in the following format" + "dd/mm/yyyy";  
#         final String Insert_Remove_PROMPT = "\n\n\n \n"  
#                 + "1) Remove Record\n"  
#                 + "2) Insert Record\n"  
#                 + "3) Return to previous menu\n"  
#                 + "4) Exit Program";  
#   
#         final String Insert_Record = "Please enter new record in the following format: Serial Number|SXXXXXXXG|Name | Country |MM/DD/YYYY | Time in 24 hr clock | Country | MM/DD/YYYY | Time in 24 hr clock";  
#         final String Delete_Record = "Please enter the serial number of the record to delete";  
#         //declare var to contain the record files  
#   
#   
#         int index;  
#         String NRIC;  
#         String Name;  
#         String srcCountry;  
#         String deptDate;  
#         String deptTime;  
#         String destCountry;  
#         String arrDate;  
#         String arrTime;  
#   
#   
#         //delare and initiate new linked list  
#   
#         LinkedList<Travel> LL = new LinkedList<Travel>();  
#   
#   
#         try {  
#   
#             //initiate filereader and bufferedreader objects  
#   
#             fr = new FileReader(inFile);  
#             br = new BufferedReader(fr);  
#   
#             //read 1 line from the file  
#             line = br.readLine();  
#   
#             // while line is not null  
#   
#             while (line != null) {  
#                 StringTokenizer tokenizer = new StringTokenizer(line, "|");  
#                 index = Integer.parseInt(tokenizer.nextToken());  
#                 NRIC = tokenizer.nextToken();  
#                 Name = tokenizer.nextToken();  
#                 srcCountry = tokenizer.nextToken();  
#                 deptDate = tokenizer.nextToken();  
#                 deptTime = tokenizer.nextToken();  
#                 destCountry = tokenizer.nextToken();  
#                 arrDate = tokenizer.nextToken();  
#                 arrTime = tokenizer.nextToken();  
#                 //create new Travel object  
#                 Travel travel = new Travel(index, NRIC, Name, srcCountry, deptDate, deptTime, destCountry, arrDate, arrTime);  
#   
#                 //add this item object to Llist  
#                 LL.addFirst(travel);  
#   
#                 //read another line from file  
#                 line = br.readLine(); <=== over here is the error for outof memory heap error  
#   
#             }  
#             //close buffered reader  
#             br.close();  
#         } catch (FileNotFoundException e) {  
#             System.out.println("The file" + inFile + "was not found");  
#         } catch (IOException e) {  
#             System.out.println("Reading error");  
#         } finally {  
#             //close filereader  
#             if (fr != null) {  
#                 try {  
#                     fr.close();  
#                 } catch (IOException e) {  
#                     System.out.println("error closing file");  
#                 }  
#                 //print out the input prompt  
#   
#   
#   
#             }  
#   
#         }  
#   
#