Hashmap and finding

664 Expert 512MB

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.

Expand|Select|Wrap|Line Numbers

 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

May 7 '07 #1

Subscribe Post Reply

1753

r035198x

13,262

8TB

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.

Expand|Select|Wrap|Line Numbers

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

Expand|Select|Wrap|Line Numbers

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

make sure there was something put in hs first.

May 7 '07 #2

nomad

664

Expert 512MB

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

Expand|Select|Wrap|Line Numbers

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...

Expand|Select|Wrap|Line Numbers

   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

May 7 '07 #3

r035198x

13,262

8TB

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

Expand|Select|Wrap|Line Numbers

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

Expand|Select|Wrap|Line Numbers

compdb = new Computer_listing(msg);

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

May 7 '07 #4

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