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POWriting to Binary in Java
 

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  1. POWriting to Binary in Java
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    <p>I am making a program that makes use of two Array Lists. I've researched how to write the objects to binary and I've tried implementing it but it never works correctly. I need to be able to run the program create the file and then write to the file when I want to save. The next time the program is loaded it needs to be able to read the array lists back in. I already have Serializable implemented in my two objects that I'm storing.</p> <pre><code>import java.util.ArrayList; import java.util.Scanner; import java.io.*; //Add person functionality next public class main { ArrayList&lt;Person&gt; people = new ArrayList&lt;Person&gt;(); ArrayList&lt;Date&gt; dates = new ArrayList&lt;Date&gt;(); //Possibly add a checkExistence Function somewhere //Otherwise self explanatory public boolean newPerson(){ Scanner kbd = new Scanner(System.in); String input = ""; boolean nameIsCorrect = false; boolean typeIsCorrect = false; do{ boolean nameContinue = false; while(!nameContinue){ System.out.println("What is the name?"); input = kbd.nextLine(); nameContinue = yesOrNo(); if(nameContinue){ nameContinue = checkForExistence(input); if(!nameContinue){ System.out.println("Name already exists, try again"); } } } String[] tokens = input.split(" "); if(tokens.length == 1){ String name = tokens[0]; String type = ""; do{ System.out.println("What type? F (Family) P (Punch) S (Season)"); input = kbd.nextLine(); if(input.equalsIgnoreCase("f")){ type = "f"; typeIsCorrect = true; nameIsCorrect = true; } else if(input.equalsIgnoreCase("s")){ type = "s"; typeIsCorrect = true; nameIsCorrect = true; } else if(input.equalsIgnoreCase("p")){ type = "p"; typeIsCorrect = true; nameIsCorrect = true; } else{ System.out.println("Invalid, try again"); } } while(!typeIsCorrect); Person np = new Person(name, type); people.add(np); System.out.println(np.getName() + " added!"); } else{ System.out.println("Not correct format let's try again"); } } while(!nameIsCorrect); return true; }//End of newPerson function //Cycles through and prints a roster public boolean printPeopleList(){ for(int i = 0; i &lt; people.size(); i++){ System.out.println(people.get(i).getName()); } return true; } //Testing for valid input public boolean testDateValidity(String input, int which){ if(which == 1){ String[] dates = new String[21]; int count = 0; for(int i = 1; i &lt;= 12; i++){ if(i &lt; 10){ dates[count] = "0" + Integer.toString(i); count++; } dates[count] = Integer.toString(i); count++; } for(int j = 0; j &lt; dates.length; j++){ if(input.equalsIgnoreCase(dates[j])){ return true; } } } else if(which == 2){ String[] dates = new String[40]; int count = 0; for(int i = 1; i &lt;= 31; i++){ if(i &lt; 10){ dates[count] = "0" + Integer.toString(i); count++; } dates[count] = Integer.toString(i); count++; } for(int j = 0; j &lt; dates.length; j++){ if(input.equalsIgnoreCase(dates[j])){ return true; } } } else{ return false; } return false; } //Cycles through and prints all dates and their attendance public boolean printListOfDates(){ System.out.println("Date\tPeople"); for(int i = 0; i &lt; dates.size(); i++){ System.out.println(dates.get(i).toString()); } return true; } public boolean printCurrentPeople(int day){ dates.get(day).printList(); return true; } //Returns the day position from the ArrayList public int findDayPosition(String month, String day){ for(int i = 0; i &lt; dates.size(); i++){ if(month.equalsIgnoreCase(dates.get(i).getMonth()) &amp;&amp; day.equalsIgnoreCase(dates.get(i).getDay())){ return i; } } return -1; } public boolean addVisit(String name, int date){ for(int i = 0; i &lt; people.size(); i++){ if(people.get(i).getName().equalsIgnoreCase(name)){ people.get(i).incrementVisits(); people.get(i).addDay(dates.get(date).toStringPerson()); dates.get(date).addVisitor(name); return true; } } System.out.println("Person not found"); return false; } public boolean addVisit(String name, int visits, int date){ for(int i = 0; i &lt; people.size(); i++){ if(people.get(i).getName().equalsIgnoreCase(name)){ people.get(i).incrementVisits(visits); dates.get(date).addVisitor(name, visits); people.get(i).addDay(dates.get(date).toStringPerson(), visits); return true; } } System.out.println("Person not found"); return false; } public boolean regAdd(int date){ dates.get(date).addRegular(); return true; } public boolean regAdd(int date, int visits){ dates.get(date).addRegular(visits); return true; } public boolean helpFunction(){ File fin = new File("help.txt"); if(!fin.exists()){ System.out.println("I'm sorry the help file has become corrupted :("); System.out.println("Please contact the maker of this program to fix it"); System.out.println("Upon contact he will probably let out a loud UGH"); } else{ try{ FileReader fr = new FileReader(fin); BufferedReader br = new BufferedReader(fr); String line; while((line = br.readLine()) != null){ System.out.println(line); } } catch (FileNotFoundException fnf) { //This line is completely pointless as the if function above serves its purpose System.out.println("File was not found"); } catch (IOException e) { e.printStackTrace(); } } return true; } public boolean checkExistence(String name){ for(int i = 0; i &lt; people.size(); i++){ if(people.get(i).getName().equalsIgnoreCase(name)){ return true; } } return false; } public int getPersonPosition(String name){ for(int i = 0; i &lt; people.size(); i++){ if(people.get(i).getName().equalsIgnoreCase(name)){ return i; } } return -1; } public boolean printPersonDates(String name){ int x = getPersonPosition(name); people.get(x).printDates(); return true; } public String changeMonth(){ Scanner kbd = new Scanner(System.in); String input; boolean continueProgram = false; boolean monthContinue = false; //Recieve the date do{ System.out.println("What is the month?"); input = kbd.nextLine(); monthContinue = testDateValidity(input, 1); if(monthContinue){ continueProgram = true; } } while (!continueProgram); String month = input; return month; } public String changeDay(){ Scanner kbd = new Scanner(System.in); String input; boolean continueProgram = false; boolean dayContinue = false; //Recieve the date do{ System.out.println("What is the day?"); input = kbd.nextLine(); dayContinue = testDateValidity(input, 2); if(dayContinue){ continueProgram = true; } } while (!continueProgram); String day = input; return day; } public boolean yesOrNo(){ Scanner kbd = new Scanner(System.in); String input; do{ System.out.println("Are you sure? Y or N"); input = kbd.nextLine(); } while(!checkYes(input)); if(input.equalsIgnoreCase("y") || input.equalsIgnoreCase("yes")){ return true; } else if(input.equalsIgnoreCase("n") || input.equalsIgnoreCase("no")){ return false; } else{ return false; } } public boolean checkYes(String input){ if(input.equalsIgnoreCase("y") || input.equalsIgnoreCase("yes")){ return true; } else if(input.equalsIgnoreCase("n") || input.equalsIgnoreCase("no")){ return true; } else{ return false; } } public boolean checkForExistence(String input){ for(int i = 0; i &lt; people.size(); i++ ){ if(input.equalsIgnoreCase(people.get(i).getName())){ return false; } } return true; } //Main Function public static void main(String[] args){ main pool = new main(); Scanner kbd = new Scanner(System.in); String input; int numberData; boolean continueProgram = false; String month; String day; int dayPosition; String dateString; System.out.println("Welcome to the Pool Database Management System"); System.out.println("Copyright 2011 by Dalton Dick"); boolean monthContinue = false; //Recieve the date do{ System.out.println("What is the month?"); input = kbd.nextLine(); monthContinue = pool.testDateValidity(input, 1); if(monthContinue){ continueProgram = true; } } while (!continueProgram); month = input; continueProgram = false; boolean dayContinue = false; //Recieve the date do{ System.out.println("What is the day?"); input = kbd.nextLine(); dayContinue = pool.testDateValidity(input, 2); if(dayContinue){ continueProgram = true; } } while (!continueProgram); day = input; //Adding the date object or finding the date already stored if(pool.findDayPosition(month, day) != -1){ dayPosition = pool.findDayPosition(month, day); System.out.println("Date already exists, using."); } else{ Date dayObject = new Date(month, day); pool.dates.add(dayObject); dayPosition = pool.findDayPosition(month, day); System.out.println("Date added"); } continueProgram = true; boolean needsAFunction = true; while(continueProgram){ System.out.println("Please enter a command"); input = kbd.nextLine(); String[] tokens = input.split(" "); if(tokens[0].equalsIgnoreCase("help")){ if(tokens.length == 1){ pool.helpFunction(); } else{ System.out.println("Invalid Command"); } } else if(tokens[0].equalsIgnoreCase("new")){ if(tokens.length == 1){ pool.newPerson(); } else{ System.out.println("Invalid Command"); } } else if(tokens[0].equalsIgnoreCase("print")){ if(tokens.length == 2){ if(tokens[1].equalsIgnoreCase("people")){ pool.printPeopleList(); } else if(tokens[1].equalsIgnoreCase("dates")){ pool.printListOfDates(); } else if(tokens[1].equalsIgnoreCase("current")){ pool.printCurrentPeople(dayPosition); } }//End if Statement else if(tokens.length == 3){ if(pool.checkExistence(tokens[1])){ if(tokens[2].equalsIgnoreCase("dates")){ pool.printPersonDates(tokens[1]); } else{ System.out.println("Invalid"); } } else{ System.out.println("Person does not exist"); } } } else if(tokens[0].equalsIgnoreCase("quit") || tokens[0].equalsIgnoreCase("q") || tokens[0].equalsIgnoreCase("exit")){ System.out.println("Exiting System"); System.exit(0); } else if(tokens[0].equalsIgnoreCase("add")){ if(tokens.length == 1){ System.out.println("Invalid use of the command"); } else if(tokens.length == 2){ pool.addVisit(tokens[1], dayPosition); } else if(tokens.length == 3){ try{ int x = Integer.parseInt(tokens[2]); pool.addVisit(tokens[1], x, dayPosition); } catch (NumberFormatException nfe){ System.out.println("Not a number"); }//End try catch block }//End else if } else if(tokens[0].equalsIgnoreCase("change")){ if(tokens.length == 2){ if(tokens[1].equalsIgnoreCase("date")){ month = pool.changeMonth(); day = pool.changeDay(); if(pool.findDayPosition(month, day) != -1){ dayPosition = pool.findDayPosition(month, day); System.out.println("Date already exists, using."); } else{ Date dayObject = new Date(month, day); pool.dates.add(dayObject); dayPosition = pool.findDayPosition(month, day); System.out.println("Date added"); } } else{ System.out.println("Invalid Command"); } } else{ System.out.println("Invalid Command"); } } else if(tokens[0].equalsIgnoreCase("regular") || tokens[0].equalsIgnoreCase("reg")){ if(tokens.length == 1){ pool.regAdd(dayPosition); } else if(tokens.length == 2){ try{ pool.regAdd(dayPosition, Integer.parseInt(tokens[1])); } catch (NumberFormatException nfe) { System.out.println("Not correct input"); } } } else{ System.out.println("Invalid Command"); } } } } </code></pre>
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    1. USRumel
    1. USRumel
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      1. VTUpMod
    1. COPlease post some code, otherwise we have no idea of what's going wrong. Personally I'd avoid the built-in Java serialization, but that's a different decision.
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      1. POWriting to Binary in Java
      1. USJon Skeet
    2. COplease post a *minimal complete* program that shows what's happening.
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      1. USjcomeau_ictx
 

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