HELP NEEDED~~

[Jose Cisse]

   private void removeinventoryItem()
  {
    displayinventory();
    ArrayList items = inventory.getInventoryItems();
    int toRemove = 0;
    System.out.println("\nRemove Book Item from Inventory");
    System.out.print("Enter number of Book item: ");
    toRemove = in.readInteger();
    if ((toRemove > 0) && (toRemove <= items.size()))
    {
      inventory.removeItem(toRemove - 1);
     [B] System.out.println("The entry for: " +  InventoryItem.getName()+ " has been removed");[/B]
    }
    else
    {
      System.out.println("Invalid item number, nothing removed");
    }
  }   

in this bit:"System.out.println("The entry for: " + InventoryItem.getName()+ " has been removed");"

how do you make the name of the book shown after"The entry for: "???
code " InventoryItem.getName()" doesnt work actually~~~error message coming out:" non-static method getName() cannot be referenced from a static context"

AND basically in my InventoryItem, it looks like:

 import java.util.ArrayList;
 
public class InventoryItem
{
  private String name;
  private int price;
  public InventoryItem(String name, int price)
  {
    this.name = name;
    this.price = price;
  }
  public String getName()
  {
    return name;
  }
  public int getPrice()
  {
    return price;
  }
}   

so where is the problem???

[ March 22, 2006: Message edited by: Jose Cisse ]

[ March 22, 2006: Message edited by: Jose Cisse ]
[ March 22, 2006: Message edited by: Jose Cisse ]

[Paul Sturrock]

InventoryItem's getName() method is not static, so you can't access it in a static way. You need an instance of InventoryItem to call the getName() method on.

For example:

public class Foo {
   public static void doSomething() {
       // does something 
   }
}
 
public class Bar {
    public void doSomething() {
        // does something
    }
}
 
public class MyApp {
    
    public static void main(String [] args] {
        Foo.doSomething();   // fine
        Bar.doSomething()    // illegal 
 
        Foo myFoo = new Foo();
        Bar myBar = new Bar();
 
        myFoo.doSomething();   // OK, but unnecessary since the method is static
        myBar.doSomething(); // Fine
    }

[Jonathan Moore]

Hi Jose,

You need to reference the actual item you are removing from the ArrayList and call getName() on it - as Paul said you are trying to call the method on the class, not the object.

As far as I'm aware ArrayList doesn't have a removeItem() method, but it does have a remove() method which returns the object you are removing. So you can replace your two lines of code with:

 
InventoryItem item = (InventoryItem)inventory.remove(toRemove - 1);
System.out.println("The entry for: " +  item.getName()+ " has been removed");

Cheers
Jon

[Jose Cisse]

 
InventoryItem item = (InventoryItem)inventory.remove(toRemove - 1);
System.out.println("The entry for: " +  item.getName()+ " has been removed");

Cheers
Jon[/qb]<hr></blockquote>

thanks for your help~~~

for "InventoryItem item = (InventoryItem)inventory.remove(toRemove - 1);"
i got a error message:"cannot resolve symbol - method remove(int)"
...so seems i need more your help~~~

[ March 22, 2006: Message edited by: Jose Cisse ]

[Jose Cisse]

???

[marc weber]

Originally posted by Jose Cisse:
...for "InventoryItem item = (InventoryItem)inventory.remove(toRemove - 1);"
i got a error message:"cannot resolve symbol - method remove(int)"...

I don't know what type "inventory" is, but it does not appear to have a remove(int) method.

It seems that you're trying to treat "inventory" as an ArrayList, but that doesn't quite make sense because your original post has a line...

ArrayList items = inventory.getInventoryItems();

So the question is: What type is "inventory"?

[Jose Cisse]

how about i change them to:

if ((toRemove > 0) && (toRemove <= items.size()))
    {
      InventoryItem temp=（InventoryItem)inventory.get(toRemove - 1);
      inventory.removeItem(toRemove - 1);
      System.out.println("The entry for: " +  temp.getName()+ " has been removed");
    }

[ March 22, 2006: Message edited by: Jose Cisse ] :roll:
[ March 22, 2006: Message edited by: Jose Cisse ]

[marc weber]

Originally posted by Jose Cisse:
how about i change them to...

Did it work?

The question is still the same: What type is "inventory"? And are you calling the proper methods defined in that type?

[Jose Cisse]

Originally posted by marc weber:

Did it work?

The question is still the same: What type is "inventory"? And are you calling the proper methods defined in that type?

no it doesnt, for line

" InventoryItem temp=(InventoryItem)inventory.get(toRemove - 1);"

cannot resolve symbol-method get(int)... ...



and in my inventory class , i did like:

 import java.util.ArrayList;
public class inventory
{
  private ArrayList inventoryList;
  public inventory()
  {
    inventoryList = new ArrayList();
  }
  public ArrayList getInventoryItems()
  {
    return inventoryList;
  }
  public void addItem(String name, String description,  int price)
  {
    inventoryList.add(new InventoryItem(name, description,  price));
  }
  public void removeItem(int n)
  {
    inventoryList.remove(n);
  }
... ...     

[Christophe Verré]

A little advice:
You should do some basic tutorials first.
You don't seem to know the basics, and you don't understand the compiler errors. 'Trial and error' will not resolve your problems.

[marc weber]

Your inventory class does not seem to have a method called "get," so "inventory.get()" does not work.

Your inventory class does not seem to have a method called "remove," so "inventory.remove()" does not work.

Is there a method in your inventory class that you want to call?

Hint: I think you took a wrong turn several posts above when an assumption was made that "inventory" represented an ArrayList.

[Jonathan Moore]

Hmm, sorry I didn't read it properly - I was assuming inventory was the ArrayList.

You won't be able to call get() on your inventory item because you haven't defined a get() method. You can either define a get() method and your code snippet should work, or you could change your inventory class so that the removeItem() method returns the item you have removed. Wither way will obtain a reference to the item you are about to remove so that you can call getName() on it.

Another tip - you should capitalise class names, so call your class Inventory rather than inventory.

Cheers
Jon

[Jose Cisse]

i think i defined get() method in my InventoryItem class, plz have a look:

  import java.util.ArrayList;
 
public class InventoryItem
{
  private String name;
  private String description;
  private int price;
  public  InventoryItem(String name, String description, int price)
  {
    this.name = name;
    this.description = description;
    this.price = price;
  }
  public String getName()
  {
    return name;
  }
  public String getDescription()
  {
    return description;
  }
 
  public int getPrice()
  {
    return price;
  }
}  

[marc weber]

Originally posted by Jonathan Moore:
Hmm, sorry I didn't read it properly - I was assuming inventory was the ArrayList...

Yeah, it's hard to get a good overall picture based on snippets.

[marc weber]

Originally posted by Jose Cisse:
i think i defined get() method in my InventoryItem class...

No. InventoryItem has a few "getter" methods: getName, getDescription, and getPrice. But it does not have a method simply called "get."

Also, Inventory and InventoryItem are two different classes, neither of which extend the other. So even if InventoryItem did have a "get" method, that would not allow you to call "get" on an instance of Inventory.
[ March 23, 2006: Message edited by: marc weber ]

[Christophe Verré]

i think i defined get() method in my InventoryItem class...

Good luck Marc.

[Jose Cisse]

oh~~~finally i figured it out~~~many thanks for you guys~~~

[Christophe Verré]

Jose,
that's cool you've figured it out.

You may be interested to read a tutorial :
http://java.sun.com/docs/books/tutorial/