Hashmap and finding

**r035198x** · May 7 '07, 05:26 PM

Originally posted by nomad

When I run choice == 2 I'm suppose to a an out.println back finding a product.
but I get Null for all the values.
Can someone help me with this.

Code:

class Computer_listing {
 
	private String id;
 
	private String name;
 
	private int harddrive;
 
	private int memory;
 
	private float speed;
 
	public Computer_listing(String idx) {
 
	this.id = idx;
 
	}
 
 
	public Computer_listing(String cd, String cn, int hd, int me,
			float sp) {
		this.id = cd;
		this.name = cn;
		this.harddrive = hd;
		this.memory = me;
		this.speed = sp;
 
	}
 
	public String getId() {
 
		return this.id;
 
	}
 
	public String getName() {
 
		return this.name;
 
	}
 
	public int getHardrive() {
 
		return this.harddrive;
 
	}
 
	public int getMemory() {
 
		return this.memory;
 
	}
 
	public float getSpeed() {
 
		return this.speed;
 
	}
 
	public void setId(String cd) {
 
		this.id = cd;
	}
 
	public void setName(String cn) {
 
	this.name = cn;
 
	}
 
	public void setHarddrive(Integer hd) {
 
		this.harddrive = hd;
 
	}
 
	public void setMemory(Integer me) {
 
		this.memory = me;
 
	}
 
	public void setSpeed(float sp) {
 
		this.speed = sp;
 
	}
}
 
 
public class ComputerInvent{
 
 
public static void main(String s[]){
 
HashMap<String,Computer_listing> hs = new HashMap<String,Computer_listing>();
Computer_listing[] computer = new Computer_listing[2];
computer[0] = new Computer_listing("IBM123", "IBM ThinkCentera",2, 5000, 340);
computer[1] = new Computer_listing("Apple", "15 PowerBook", 2, 5000, 340);
Scanner kbd = new Scanner(System.in);
			int choice;
			System.out.println("Make a Section: ");
			System.out.println("1. Enter Info ");
			System.out.println("2. Print all ");
			System.out.println("3. Exit ");
			System.out.print("\nPlease press Enter afer each response");
			System.out.println("Enter your chose please: ");
			choice = kbd.nextInt();
			kbd.nextLine();
 
			if (choice == 2) {
				 Collection<Computer_listing> values = hs.values();
 
		 Scanner kbd2 = new Scanner(System.in);
					int choice2;//new section making
					System.out.println("Make a Section: ");
					System.out.println("1. Print all ");
					System.out.println("2. Exit ");
					System.out.print("\nPlease press Enter afer each response");
					System.out.println("Enter your chose please: ");
					choice2 = kbd.nextInt();
					kbd2.nextLine();
					if (choice2 == 1) {
						for (Computer_listing temp : values) {
					 System.out.println("Item is enter in the db\n");
					 System.out.printf("Id: %s \n",temp.getId());
					 System.out.printf("Product name: %s \n",temp.getName());
					 System.out.printf("Product name: %s \n",temp.getHardrive());
					 System.out.printf("Product name: %s \n",temp.getMemory());
					 System.out.printf("Product name: %s \n",temp.getSpeed());
					 System.out.println("--------------------");
						}
 
		 }// close the choice2==1
					if (choice2 == 2) {
						System.out.printf("Good bye");
					 }// close the choice2==2
 
		if (choice == 3) {
			System.out.printf("Good bye");
		}// close the choice == 3
 
		}//close else
 
 
}//close main
 
 
}//close class

thanks
Nomad

Where did you let the user enter the info?
When you do

Code:

 
Collection<Computer_listing> values = hs.values();

make sure there was something put in hs first.

**nomad** · May 7 '07, 05:38 PM

Originally posted by r035198x

Where did you let the user enter the info?
When you do

Code:

 
Collection<Computer_listing> values = hs.values();

make sure there was something put in hs first.

here is the input section for the user...
Same Class...

Code:

  public static void main(String s[]){

         HashMap<String,Computer_listing> hs = new HashMap<String,Computer_listing>();
         Computer_listing[] computer = new Computer_listing[2];
         computer[0] = new Computer_listing("IBM123", "IBM ThinkCentera",2, 5000, 340);
         computer[1] = new Computer_listing("Apple", "15 PowerBook", 2, 5000, 340);
        
         
         Scanner kbd = new Scanner(System.in);
			int choice;
			System.out.println("Make a Section: ");
			System.out.println("1. Enter Info ");
			System.out.println("2. Print all ");
			System.out.println("3. Exit ");
			System.out.print("\nPlease press Enter afer each response");
			System.out.println("Enter your chose please: ");
			choice = kbd.nextInt();
			kbd.nextLine();
			if (choice == 1) {
         Scanner ifput = new Scanner(System.in);
         ifput.useDelimiter("\r\n");

           while(true){

               String msg = null;
               Computer_listing compdb = null;

                System.out.println("Enter <ComputerID> ie IBM123A - Type <Stop> to print");
           	msg = ifput.next();

                if (msg.equalsIgnoreCase("STOP"))

		  break;

            	else
		  compdb = new Computer_listing(msg);

                System.out.println("Enter Computer Name:");
		compdb.setName(ifput.next());

		System.out.println("Enter HardDrive: ie 12");
		compdb.setHarddrive(Integer.parseInt(ifput.next()));


		System.out.println("Enter Memory: ie 7865");
		compdb.setMemory(Integer.parseInt(ifput.next()));

		System.out.println("Enter Clock Speed: ie 765.00");
		compdb.setSpeed(Float.parseFloat(ifput.next()));

                hs.put(msg,compdb);

          }

          System.out.println("<Done>");

          Collection<Computer_listing> values = hs.values();
          int i = 0;

          for (Computer_listing temp : values) {
        	System.out.println("Item is enter in the db\n");
        	System.out.printf("Product Id: %s \n",temp.getId());
        	System.out.printf("Product Name: %s \n",temp.getName());
        	System.out.printf("Product Hardrive: %s \n",temp.getHardrive());
        	System.out.printf("Product Memory: %s \n",temp.getMemory());
        	System.out.printf("Product Speed: %s \n",temp.getSpeed());
        	System.out.println("--------------------");
			i++;

          }
			} // close the if loop

nomad

**r035198x** · May 7 '07, 05:45 PM

Originally posted by nomad

here is the input section for the user...
Same Class...

Code:

 public static void main(String s[]){
 
HashMap<String,Computer_listing> hs = new HashMap<String,Computer_listing>();
Computer_listing[] computer = new Computer_listing[2];
computer[0] = new Computer_listing("IBM123", "IBM ThinkCentera",2, 5000, 340);
computer[1] = new Computer_listing("Apple", "15 PowerBook", 2, 5000, 340);
 
 
Scanner kbd = new Scanner(System.in);
			int choice;
			System.out.println("Make a Section: ");
			System.out.println("1. Enter Info ");
			System.out.println("2. Print all ");
			System.out.println("3. Exit ");
			System.out.print("\nPlease press Enter afer each response");
			System.out.println("Enter your chose please: ");
			choice = kbd.nextInt();
			kbd.nextLine();
			if (choice == 1) {
Scanner ifput = new Scanner(System.in);
ifput.useDelimiter("\r\n");
 
while(true){
 
String msg = null;
Computer_listing compdb = null;
 
System.out.println("Enter <ComputerID> ie IBM123A - Type <Stop> to print");
	msg = ifput.next();
 
if (msg.equalsIgnoreCase("STOP"))
 
		 break;
 
	else
		 compdb = new Computer_listing(msg);
 
System.out.println("Enter Computer Name:");
		compdb.setName(ifput.next());
 
		System.out.println("Enter HardDrive: ie 12");
		compdb.setHarddrive(Integer.parseInt(ifput.next()));
 
 
		System.out.println("Enter Memory: ie 7865");
		compdb.setMemory(Integer.parseInt(ifput.next()));
 
		System.out.println("Enter Clock Speed: ie 765.00");
		compdb.setSpeed(Float.parseFloat(ifput.next()));
 
hs.put(msg,compdb);
 
}
 
System.out.println("<Done>");
 
Collection<Computer_listing> values = hs.values();
int i = 0;
 
for (Computer_listing temp : values) {
	System.out.println("Item is enter in the db\n");
	System.out.printf("Product Id: %s \n",temp.getId());
	System.out.printf("Product Name: %s \n",temp.getName());
	System.out.printf("Product Hardrive: %s \n",temp.getHardrive());
	System.out.printf("Product Memory: %s \n",temp.getMemory());
	System.out.printf("Product Speed: %s \n",temp.getSpeed());
	System.out.println("--------------------");
			i++;
 
}
			} // close the if loop

nomad

In

Code:

compdb = new Computer_listing(msg);

are you creating a Computer_listin g object using only one String as parameter?
Where is the constructor that takes that?

Hashmap and finding

Hashmap and finding

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