Thread: Why when I have successfully added my parts, the output is null and false?

import java.util.ArrayList;
public class BikePartsDB {
private static ArrayList<BikeParts> bikepartsList = new ArrayList<BikeParts>();

public static void showBikePartsMenu() {
//Display the menu
System.out.println("Option 1: View all Bike Parts");
System.out.println("Option 2: Add a new Bike Parts");
System.out.println("Option 3: Delete a Bike Parts");
System.out.println("Option 4: Exit");
}

public static void addBike(BikeParts bk) {
//add some data to the list
bikepartsList.add(bk);
if (bikepartsList.size() != 0) {
System.out.println("Successfully added!");
}
else {
System.out.println("Add fail!");
}
}


public static void viewAllBikeParts() {

if (bikepartsList.size() == 0) {
System.out.println("No bike parts.");
}

else {
//display all Customers in the list
String output = String.format("%-10s %-10s %-10s %-10s\n", "NO.", "PARTNAME", "DESCRIPTION", "AVAILABILITY");
for (int i = 0; bikepartsList.size() > i; i++) {
output += String.format("%-10d %-10s %-10s %-10s\n", i + 1, bikepartsList.get(i).getPartName(), bikepartsList.get(i).getDescription(), bikepartsList.get(i).isAvailable());
}
System.out.println(output);
}

}

public static void delBike(int BikepartsID) {
//clean up the data in the list
bikepartsList.remove(BikepartsID - 1);
}
public static void processOption(int subOption) {

while (subOption != 4) {
showBikePartsMenu();
subOption = Helper.readInt("Enter option > ");
if (subOption == 1) {
// View all bike part
viewAllBikeParts();


} else if (subOption == 2) {
// Add a bike part
BikeParts newBikeparts = inputBikePartsToAdd();

addBike(newBikeparts);




} else if (subOption == 3) {
// Delete a bike part
viewAllBikeParts();
int delete = selectBikePartsToDelect1();
int size = bikepartsList.size();
delBike(delete);
if (size != bikepartsList.size()) {
System.out.println("Successfully deleted!");
}
else {
System.out.println("Delete unsuccessful");
}

}else if (subOption == 4) {
System.out.println("End of tasks");
break;
}
//invalid option
else {
System.out.println("Invalid type");
}
}

//show the menu again & ask for option
showBikePartsMenu();


}



//==========Option 1 ==============



//==========Option 2 ==============
public static BikeParts inputBikePartsToAdd() {
String partName = Helper.readString("Enter Part Name > ");
String description = Helper.readString("Enter Description > ");
boolean isAvailable = Helper.readBoolean("Enter Availability > ");

BikeParts newBikeparts = new BikeParts(partName, description, isAvailable);
return newBikeparts;
//request user for the bike part to add to the list
}



//==========Option 3 ==============
public static int selectBikePartsToDelect1() {
//request the user to select bike part for process

int number = Helper.readInt("Enter NO. to delete > ");
return number;

}

public static void delBikeParts(int bikepartsID) {
//remove bike part to list

}

public static void populateBikePartsDB() {
// TODO Auto-generated method stub

}

public static void cleanupBikePartsDB() {
// TODO Auto-generated method stub

}

public static void removeAll() {
// TODO Auto-generated method stub

}

public static Object getSize() {
// TODO Auto-generated method stub
return null;
}




}

This is my output:

Option 1: View all Bike Parts
Option 2: Add a new Bike Parts
Option 3: Delete a Bike Parts
Option 4: Exit
Enter option > 2
Enter Part Name > wheels
Enter Description > bike wheels
Enter Availability > true
Successfully added!
Option 1: View all Bike Parts
Option 2: Add a new Bike Parts
Option 3: Delete a Bike Parts
Option 4: Exit
Enter option > 1
NO. PARTNAME DESCRIPTION AVAILABILITY
1 null null false

I am not sure which part is causing my output to have an error.
this is my bikeparts class:

 
 
public class BikeParts{
 
		//declare class parameters
	private String partName;
	private String description;
	private boolean isAvailable;
 
 
		public BikeParts(String partName, String description, boolean isAvailable) {
			//initialize paramater
 
		}
		public String getPartName() {
			return partName;
		}
		public void setPartName(String partName) {
			this.partName = partName;
		}
		public String getDescription() {
			return description;
		}
		public void setDescription(String description) {
			this.description = description;
		}
		public boolean isAvailable() {
			return isAvailable;
		}
		public void setAvailable(boolean isAvailable) {
			this.isAvailable = isAvailable;
		}
 
		public String toString() {
	        String x = "" + this.isAvailable;
	        return x;
	    }
 
}

Do you mean something like this?

import static org.junit.Assert.*;
 
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.util.ArrayList;
 
public class BikePartsTest {
 
	private BikeParts bp1;
	private BikeParts bp2;
 
	@Before
	public void setUp() throws Exception {
		bp1 = new BikeParts("Wheels", "Bike Wheels", true);
		bp2 = new BikeParts("Handle", "Bike Handles", true);
	}
 
	@Test
	public void c206_test() {
 
		assertTrue("C206_CaseStudy_SampleTest ",true);
	}
 
	@Test
 
	public void checkForArrayList() {
		assertEquals("checks if arrayList size is 0, if there is means an arraylist is present or else there will be another error.", 0, BikePartsDB.getSize());
	}
 
	@Test
 
	public void addBikeTest() {
		BikePartsDB.addBike(bp1);
		BikePartsDB.addBike(bp2);
		assertEquals("If the size is 2 after adding, means successful added.", 2, BikePartsDB.getSize());
	}
 
 
 
	@Test	
 
	public void viewBikeTest() {
 
		//checks if there is an arraylist with the size
		checkForArrayList();
 
		//checks for output first if no customer added
 
 
 
		//checks if arraylist is there and also tests if adding is working
		addBikeTest();
 
		String output = String.format("%-10s %-10s %-15s %-15s\n", "NO.", "PARTNAME", "DESCRIPTION", "AVAILABILITY");
		output += String.format("%-10d %-10s %-15s %-15d\n", 1, "Wheels", "Bike Wheels", true);
		output += String.format("%-10d %-10s %-15s %-15d\n", 2, "Handles", "Bike Handles", true);
 
 
 
	}
 
 
	@Test
 
	public void deleteBikeTest() {
		//add and check firsts
		checkForArrayList();
		addBikeTest();
		BikePartsDB.delBike(2);
		assertEquals("Check if array size is 1. if its 1 means 1 of them has been deleted.", 1, BikePartsDB.getSize());
		BikePartsDB.delBike(1);
		assertEquals("Check if array size is 0. if its 0 means it has been deleted.", 0, BikePartsDB.getSize());
 
	}
 
 
	@After
	public void tearDown() throws Exception {
 
		bp1 = null;
		bp2 = null;
		BikePartsDB.removeAll();
	}
 
}