[java]import java.io.*;
import java.net.*;
 
public class AddressDataClient implements Serializable
{
		
	public static void main (String[] args)
	{
		
		int arraySize = 4;
		AddressData[] aDetails = new AddressData[arraySize]; //input into memory (RAM): instance of array (size3)
	
		for(int i = 0;i<aDetails.length;i++) //inputs default data into declared array 
			aDetails[i] = new AddressData();
		
		aDetails = ReadData(aDetails);
	
		int choices =0;
			//shows menu until quit condition is met
		do 
		{
			choices = printMenu();//shows menu and gets input
			choices = menuSelect(choices, aDetails, arraySize);//processes input
		} while (choices != -1);
		
		WriteData(aDetails);
		SaveData(aDetails);
	}
 
	public static int printMenu()  
	{
        System.out.println("\nPlease Select from the following options:");
        System.out.println("[1] Add\n[2] Modify\n[3] Delete\n[4] Search\n[5] Display\n[6] Quit");
		int choice = MyInput.readInt();//choice declared and initialised in one step
		return choice;
	}
	//input : an integer choice holding the users menu selection
	//	: an AddressData object aDetails where address data is stored
	//output: returns an integer choice to control loop in main
	//processes menu selection and calls further functionality
	
	public static int menuSelect(int choice, AddressData[] aDetails, int arraySize) 
	{
		switch(choice) 
		{
		case 1:Add(aDetails, arraySize);
		break;
		case 2:Modify(aDetails);
		break;
		case 3:Delete(aDetails); 
		break;
		case 4:Search(aDetails); 
		break;
		case 5:Display(aDetails);
		break;
		case 6:System.out.println("Thank You for using this. Goodbye!");  
	  	choice = -1;
	  	break;
	  	default:System.out.println("Invalid Selection - try again");
		}
		return choice;
	}
	//input : an integer choice holding the users menu selection
	//	: an AddressData object aDetails where address data is stored
	//output: returns an integer choice to control loop in main
	//processes user choice and calls chosen method
 
	public static void Search(AddressData[] aDetails)
	{
		int result =0;
		String name;
 
		for(int i =0;i<aDetails.length;i++)
		{
			aDetails[i].PrintAll();
		}
		
 
		System.out.print("Enter the LAST NAME you wish to search for -> ");
		name = MyInput.readString();
		result = SearchLastName(aDetails, name);
				
		
		if(result != -1)
		{
			System.out.println("The record was found at position " +result+ "\n");
		}else{
			System.out.println("No record found with the surname " +name+ "\n");
		}
	}
	//input: an addressdata object aDetails where address data is stored
	//			integer result (from SearchLastName method)
	//output: prints AddressData aDetails to screen
	//			AddressData object aDeatails along with a string name datatype object
	//prints out AddressData aDetails to screen, searches aDetails for user's entry by pasing string
	//to "SearchLastName" method and prints result to screen.
		
		
	public static int SearchLastName(AddressData[] aDetails, String surname)
	{
		int result=-1;
			
		for(int i =0;i<aDetails.length;i++)
			if(aDetails[i].getLastName().equalsIgnoreCase(surname))
		
		result = i;
		return result;
	}
	//input: AddressData object aDetails along with a string namedatatype object
	//output: returns an integer result to its calling method
	//searches aDetails for string surname (from Search method) and returns integer result
		
 
	public static void Add(AddressData[] aDetails, int arraySize)
	{
		String firstname, lastname, street, suburb = null;
		int streetnum, code = 0;
		
		//This decrement is to obtain correct array size:
		arraySize--;	
		
		//Check whether the array is full:
		if(aDetails[arraySize].getFirstName() != "firstname")
		{
			System.out.println("ERROR: Cannot add entry because AddressBook maybe full. Please first delete an\n\tentry to add new entry or modify an existing entry.\n\t(IGNORE THIS MESSAGE IF PROMPTED TO ENTER FIRSTNAME)\n");
		}
	
		for(int i =0;i<aDetails.length;i++)
			if(aDetails[i].getFirstName() == "firstname")
			{
				System.out.print("Enter FirstName -> ");
				firstname = MyInput.readString();
				aDetails[i].setFirstName(firstname);
				System.out.print("Enter LastName -> ");
				lastname = MyInput.readString();
				aDetails[i].setLastName(lastname);
				System.out.print("Enter Street Number -> ");
				streetnum = MyInput.readInt();
				aDetails[i].setStreetNumber(streetnum);
				System.out.print("Enter StreetName -> ");
				street = MyInput.readString();
				aDetails[i].setStreetName(street);
				System.out.print("Enter Suburb -> ");
				suburb = MyInput.readString();
				aDetails[i].setSuburb(suburb);
				System.out.print("Enter PostCode -> ");
				code = MyInput.readInt();
				aDetails[i].setPostCode(code);
				i = aDetails.length;
			}
	}
	//input: AddressData object aDetails 
	//output: modified AddressData aDetails, screen output of menu, new AdressData aDetails entry 
	//'for' loop looks for an "empty" spot in AddressData aDetails, if found user enters new entry if not user is given
	//a message. 
 
	public static void Delete(AddressData[] aDetails)
	{
		int iUser, result =0;
		String name, firstname, lastname, street, suburb = null;
				
		for(int i =0;i<aDetails.length;i++)
		{
			aDetails[i].PrintAll();
		}
		
		System.out.print("Enter the LAST NAME you wish to delete -> ");
		name = MyInput.readString();
		result = SearchLastName(aDetails, name);
				
		if(result != -1)
		{
			System.out.println("The record was found at position " +result+ "\n");
		}else{
			System.out.println("No record found with the surname " +name+ "\n");
		}
		
		System.out.print("\nDo you wish to delete this entry?\n[1] Yes\n[2] No: ");
		iUser = MyInput.readInt();
			
		while(iUser < 1 || iUser >2)
		{
			System.out.print("Invalid Choice. Please enter either 1 or 2: ");
			iUser = MyInput.readInt();
		}
			
		if(iUser == 1)
		{
			aDetails[result].setFirstName("firstname");
			aDetails[result].setLastName("lastname");
			aDetails[result].setStreetNumber(0);
			aDetails[result].setStreetName("street");
			aDetails[result].setSuburb("suburb");
			aDetails[result].setPostCode(0);
		}
				
	}
	//input: AddressData object aDetails along with a string datatype object
	//output: AddressData object and String name (to SearchLastName)
	//			Screen prompts
	//method delete prints contents of AddressData aDetails to screen, searches for user's entry
	//if user chooses to delete then record is reset to default data.
	
	public static void Display(AddressData[] aDetails)
	{
		int result, iUser =0;
		String name ;
 
		System.out.print("\nChoose whether you want to:\n[1] View ALL entries\n[2] View AN entry\n");
		iUser = MyInput.readInt();
			
		while(iUser < 1 || iUser >2)//error check user input
		{
			System.out.print("Invalid Choice. Please enter either 1 or 2");
			iUser = MyInput.readInt();
		}
		
		if(iUser ==1)
		{
			for(int i =0;i<aDetails.length;i++)
			{
				aDetails[i].PrintAll();
			}
		}else{
			System.out.print("Enter the LAST NAME you wish to search for -> ");
			name = MyInput.readString();
			result = SearchLastName(aDetails, name);
				
			if(result != -1)
			{
				System.out.println("The record was found at position " +result+ "\n");
				aDetails[result].PrintAll();
			}else{
				System.out.println("No record found with the surname " +name+ "\n");
			}
		}
	}
	//input: AddressData object aDetails and integer result
	//output: AddressData object aDetails or just a record of Address aDetails to screen
	//			string name (to SearchLastName)
	//Prompts user for choice between viewing an entry or all entries. Prints either an entry
	//or the entire AddressData aDetails to screen
 
	public static void Modify(AddressData[] aDetails)
	{
		int result;
		int choices =0;
		String name;
			
		System.out.print("Enter the LAST NAME you wish to search for -> ");
		name = MyInput.readString();
		result = SearchLastName(aDetails, name);
				
		if(result != -1)
		{
			System.out.println("The record was found at position " +result+ "\n");
		}else{
			System.out.println("No record found with the surname " +name+ "\n");
		}
		
		do 
		{
			choices = printModifyMenu(aDetails, result);//shows modify menu and gets input
		} while (choices != -1);
		
	}
	//input: AddressData object aDetails and integer result, user input choice
	//output:Addressdata object aDetails,  string name and result
	//User enters string to search, string name passed to SearchLastName method, prints result of
	//SearchLastName shows modify menu and gets user input
	
	public static int printModifyMenu(AddressData[] aDetails, int result)
	{
			
		String name, firstname, lastname, street, suburb = null;
		int streetnum, code = 0;			
			
		System.out.println("\nChoose from the following options what you want to modify:"); 
		System.out.println("[1] FirstName\n[2] LastName\n[3] StreetNumber\n[4] StreetName\n[5] Suburb\n[6] PostCode\n[7] Quit this\n");
		int choice = MyInput.readInt();
	
		switch(choice) 
		{
			case 1:	System.out.print("Enter NEW FirstName -> ");
				firstname = MyInput.readString();
				aDetails[result].setFirstName(firstname);
				break;
			case 2: System.out.print("Enter NEW LastName -> ");
				lastname = MyInput.readString();
				aDetails[result].setLastName(lastname);
				break;
			case 3:	System.out.print("Enter NEW Street Number -> ");
				streetnum = MyInput.readInt();
				aDetails[result].setStreetNumber(streetnum);
				break;
			case 4: System.out.print("Enter NEW StreetName -> ");
				street = MyInput.readString();
				aDetails[result].setStreetName(street);
				break;
			case 5:	System.out.print("Enter NEW Suburb -> ");
				suburb = MyInput.readString();
				aDetails[result].setSuburb(suburb);
				break;
			case 6: System.out.print("Enter NEW PostCode -> ");
				code = MyInput.readInt();
				aDetails[result].setPostCode(code);
				break;
			case 7:	choice = -1;
	  			break;
	  		default:System.out.println("Invalid Selection - try again");
		}
		
		return choice;
	}
	//input: AddressData object aDetails and gets user input choice
	//outputs: prints menu to screen, AddressData adetails data, and integer choice
	//Modify menu is continously printed, awaits user input and user modificaion of specific aDetails data
	//returns integer choice.
	
	public static AddressData[] ReadData(AddressData[] aDetails)
	{
		try
		{
			System.out.println("CLIENT STARTED...\n");
				
			//Create instance of socket
			Socket connectToServer = new Socket("localhost", 8000);
			
			//Setup input and output stream from/to server
			
			ObjectOutputStream oos = new ObjectOutputStream(connectToServer.getOutputStream());
			ObjectInputStream ois = new ObjectInputStream(connectToServer.getInputStream());
			
			System.out.println("Waiting for object from server...");
			aDetails =(AddressData[])ois.readObject();
			System.out.println("Object received from server!");
			
		}
		
		catch(Exception ex)
		{
			System.err.println(ex);
		}
		
		return aDetails;
	}
	
	public static void WriteData(AddressData[] aDetails)
	{
		try
		{
			//Create instance of socket
			Socket connectToServer = new Socket("localhost", 8000);
			System.out.println("Connection Accepted!");
			
			//Setup input and output stream from/to server
			//ObjectInputStream ois = new ObjectInputStream(connectToServer.getInputStream());
			ObjectOutputStream oos = new ObjectOutputStream(connectToServer.getOutputStream());
			System.out.println("Streams created!");
			
			System.out.println("Sending object to server...");
			oos.writeObject(aDetails);
			System.out.println("Object sent to server...");
		}
		
		catch(Exception ex)
		{
			System.err.println(ex);
		}
	}
	//input: AddressData object aDetails
	
	public static void SaveData(AddressData[] aDetails)
	{
		File fAddress = new File("addresses.adr");
		try
		{
			ObjectOutputStream OosAddress = new ObjectOutputStream(new FileOutputStream(fAddress));
			for(int i = 0;i<aDetails.length;i++)
			{
				if((aDetails[i].getFirstName() != "firstname")&&(aDetails[i].getLastName() != "lastname"))
				{
					OosAddress.writeObject(aDetails[i]);
				}
			}
		
			OosAddress.close();
		}
		
		catch(IOException ex)
		{
			System.out.println(ex.getMessage());
		}
	}
}
//end of AddressDataCli

[java]import java.io.*;
import java.net.*;
 
public class AddressDataServer implements Serializable
{
	public static void main (String[] args)
	{
		int arraySize = 4;
		AddressData[] aDetails = new AddressData[arraySize]; 
				
		for(int i = 0;i<aDetails.length;i++) //inputs default data into declared array 
			aDetails[i] = new AddressData();
 
		LoadData(aDetails); //inputs saved data from "addresses.adr"
		
		System.out.println("***RECORDS LOADED***\n");
		
		for(int i = 0;i<aDetails.length;i++)
		aDetails[i].PrintAll();
		
		try
		{
			System.out.println("SERVER STARTED...\n");
						
			//Create Server Socket
			ServerSocket servSock = new ServerSocket(8000);
			
			//Listen on serversocket for connection attempts and continue when a client actually does connect
			System.out.println("Waiting for Client to Connect...");
			Socket connectToClient = servSock.accept();
			System.out.println("Connection Accepted!");
			
			//Create input and output streams for data from/to client
			System.out.println("Creating Input and Output Streams...");
			ObjectInputStream ois = new ObjectInputStream(connectToClient.getInputStream());
			ObjectOutputStream oos = new ObjectOutputStream(connectToClient.getOutputStream());
			System.out.println("Streams created!");
			
			//Loop forever (at least until there is no IP connection, at which point an exception will be thrown)
			while(true)
			{
				System.out.println("Waiting...");
				
				//Send array to client
				System.out.println("Sending object to client...");
				oos.writeObject(aDetails);
				System.out.println("Object sent to client!");
		
				//Receive array from client
				System.out.println("Waiting for object from client...");
				aDetails =(AddressData[])ois.readObject();
				System.out.println("Object received from client!");
				
				//Save (modified) array (to addresses.adr):
				SaveData(aDetails);	
			}
		}
		
		catch(Exception ex)
		{
			System.err.println(ex);
		}
	}
	
	public static void LoadData(AddressData[] aDetails)
	{
		File fAddress = new File("addresses.adr");
		
		try
		{
			ObjectInputStream OisAddress = new ObjectInputStream(new FileInputStream(fAddress));
			for(int i = 0;i<aDetails.length;i++)
			{
				aDetails[i] = (AddressData)OisAddress.readObject();
			}
			OisAddress.close();
		}
		
		catch(EOFException endOfFileException)
		{
			System.out.println("All records loaded.\n");
		}
		
		catch(ClassNotFoundException classNotFoundException)
		{
			System.out.println("File does not contain data excepted\n");
		}
		
		catch(IOException ex)
		{
			System.out.println(ex.getMessage());
		}
	}
	//input: AddressData object aDetails, EOFException endOfFileexception, ClassNotFoundException 
	//classNotFoundException and IOException ex 
	//output: OisAddress.readObject().
	
	public static void SaveData(AddressData[] aDetails)
	{
		File fAddress = new File("addresses.adr");
		try
		{
			ObjectOutputStream OosAddress = new ObjectOutputStream(new FileOutputStream(fAddress));
			for(int i = 0;i<aDetails.length;i++)
			{
				if((aDetails[i].getFirstName() != "firstname")&&(aDetails[i].getLastName() != "lastname"))
				{
					OosAddress.writeObject(aDetails[i]);
				}
			}
		
			OosAddress.close();
		}
		
		catch(IOException ex)
		{
			System.out.println(ex.getMessage());
		}
	}
	//input: AddressData object aDetails, EOFException endOfFileexception, ClassNotFoundException 
	//classNotFoundException and IOException ex 
	//output: OisAddress.readObject().	
}
//end of AddressDataSer