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POJAVA: Split main into methods and put in another class?
 

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    <p>I need a little help. I'm trying to shorten my main() and move some code into methods and put it in my other class Contact.java. Like for certain things like Reading a file I want to have a method that is just for reading the file and put it in Contact.java. Same goes for Writing to file, I want a seperate method that I can call back in the main(). I understand how to make the method, but how do I call that method back into ContactList.java from Contact.java? Any suggestions? </p> <pre><code>import java.io.*; import java.util.*; public class ContactList { public static void main(String args[]) throws IOException { Contact contact; contact = new Contact(); int action = 0; ArrayList&lt;Contact&gt; contacts = new ArrayList&lt;Contact&gt;(); while (action != 6) { System.out.println("\nWelcome to Contact List DB. " + "What would you like to do? \n"); System.out.println("1. Enter a new person" + "\n" + "2. Print the contact list" + "\n" + "3. Retrieve a person's information by last name" + "\n" + "4. Retrieve a person's information by email address" + "\n" + "5. Retrieve all people who live in a given zip code" + "\n" + "6. Exit"); Scanner reader = new Scanner(System.in); reader.useDelimiter("\n"); action = reader.nextInt(); if (action &lt;= 0 || action &gt; 6) { System.out.println("Invalid selection. "); } switch (action) { case 1: { System.out.println("\nEnter Contact Last Name:"); String lastname = reader.next(); if (lastname == null) { System.out.println("\nInvalid entry. "); break; } else { contact.setLastName(lastname.toLowerCase()); } System.out.println("Enter Contact First Name: "); String firstname = reader.next(); contact.setFirstName(firstname.toLowerCase()); System.out.println("Enter Contact Street Address: "); String address = reader.next(); contact.setHouseAddress(address.toLowerCase()); System.out.println("Enter Contact City: "); String city = reader.next(); contact.setCity(city.toLowerCase()); System.out.println("Enter Contact Zip Code: "); String zip = reader.next(); contact.setZip(zip.toLowerCase()); System.out.println("Enter Contact Email: "); String email = reader.next(); contact.setEmail(email.toLowerCase()); System.out.println("Enter Contact Phone Number: "); String phone = reader.next(); contact.setPhone(phone.toLowerCase()); System.out.println("Enter Contact Notes: "); String notes = reader.next(); contact.setNotes(notes.toLowerCase()); contacts.add(contact); try { Contact c = contact; File file = new File("contactlist.csv"); // If file doesn't exists, then create it. if (!file.exists()) { file.createNewFile(); } try (PrintWriter output = new PrintWriter(new FileWriter( "contactlist.csv", true))) { output.printf("%s\r\n", c); } catch (Exception e) { } System.out.println("Your contact has been saved."); } catch (IOException e) { e.printStackTrace(); } } break; case 2: { int counter = 0; String line = null; // Location of file to read File file = new File("contactlist.csv"); // Sort contacts and print to console try { Scanner scanner = new Scanner(file); // Before printing, add each line to a sorted set. by Seth // Copeland Set&lt;String&gt; lines = new TreeSet&lt;&gt;(); while (scanner.hasNextLine()) { line = scanner.nextLine(); lines.add(line); counter++; } // Print sorted contacts to console. for (String fileLine : lines) { String outlook = fileLine.substring(0, 1).toUpperCase() + fileLine.substring(1); System.out.println(outlook); } scanner.close(); } catch (FileNotFoundException e) { } System.out.println("\n" + counter + " contacts in records."); } break; case 3: try { System.out.println("\nEnter the last" + "name to search for: "); String searchterm = reader.next(); // Open the file as a buffered reader BufferedReader bf = new BufferedReader(new FileReader( "contactlist.csv")); // Start a line count and declare a string to hold our // current line. int linecount = 0; String line; // Let the user know what we are searching for System.out.println("Searching for " + searchterm + " in file..."); // Loop through each line, putting the line into our line // variable. boolean noMatches = true; while ((line = bf.readLine()) != null) { // Increment the count and find the index of the word. linecount++; int indexfound = line.indexOf(searchterm.toLowerCase()); // If greater than -1, means we found a match. if (indexfound &gt; -1) { System.out.println("\nContact was FOUND\n" + "\nContact " + linecount + ": " + line); noMatches = false; } } // Close the file after done searching bf.close(); if (noMatches) { System.out.println("\nNO MATCH FOUND.\n"); } } catch (IOException e) { System.out.println("IO Error Occurred: " + e.toString()); } break; case 4: try { System.out.println("\nEnter the email " + "address to search for: "); String searchterm = reader.next(); // Open the file as a buffered reader BufferedReader bf = new BufferedReader(new FileReader( "contactlist.csv")); // Start a line count and declare a string to hold our // current line. int linecount = 0; String line; // Let the user know what we are searching for System.out.println("\nSearching for " + searchterm + " in file..."); // Loop through each line, put the line into our line // variable. boolean noMatches = true; while ((line = bf.readLine()) != null) { // Increment the count and find the index of the word linecount++; int indexfound = line.indexOf(searchterm.toLowerCase()); // If greater than -1, means we found a match if (indexfound &gt; -1) { System.out.println("\nContact was FOUND\n" + "\nContact " + linecount + ": " + line); noMatches = false; } } // Close the file after done searching bf.close(); if (noMatches) { System.out.println("\nNO MATCH FOUND.\n"); } } catch (IOException e) { System.out.println("IO Error Occurred: " + e.toString()); } break; case 5: try { System.out.println("\nEnter the Zipcode to search for: "); String searchterm = reader.next(); // Open the file as a buffered reader BufferedReader bf = new BufferedReader(new FileReader( "contactlist.csv")); // Start a line count and declare a string to hold our // current line. int linecount = 0; String line; // Let the user know what we are searching for System.out.println("\nSearching for " + searchterm + " in file..."); // Loop through each line, stashing the line into our line // variable. boolean noMatches = true; while ((line = bf.readLine()) != null) { // Increment the count and find the index of the word. linecount++; int indexfound = line.indexOf(searchterm.toLowerCase()); // If greater than -1, means we found a match. if (indexfound &gt; -1) { System.out.println("\nContact was FOUND\n" + "\nContact " + linecount + ": " + line); noMatches = false; } } // Close the file after done searching bf.close(); if (noMatches) { System.out.println("\nNO MATCH FOUND.\n"); } } catch (IOException e) { System.out.println("IO Error Occurred: " + e.toString()); } break; } } } } </code></pre>
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    1. COYou could easily write every "case" in separate method. Also, maybe you could check http://en.wikipedia.org/wiki/Command_pattern if the app keeps growing later.
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    2. CODon't vandalize your own questions by editing them away.
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