Stock FunctionalityHomepage  « Case Study « Stock Functionality

In this lesson we finish the model code for the case study by completing the stocking() and unstocking() methods requested by Stocking Goods Limited. These methods are delegated to, via the Services singleton, whenever a user requests stocking or unstocking within the Manufacturer Application GUI.

Updating The stocking() Methodgo to top of page Top

The stocking() method stub needs to be coded to accept a stocking amount entered in the Manufacturer GUI. We will have to update the information held in our cache map and also update the physical Manufacturer file held on disk. We must also ensure that the stock ordered hasn't been set by another user, before setting our locks and updating the information.

Open the StockImpl class in your text editor and cut and paste the following stocking() method into the StockImpl class overwriting the existing stocking() method and comments. This stock() method can be found near the bottom of the StockImpl class.


    /**
     * Stock the requested amount entered by a user in the GUI.
     *
     * @param name The name of the Manufacturer.
     * @param location The location where the Manufacturer is based.
     * @param stockLevel The amount of stock left.
     * @param stockOrdered The amount of stock requested.
     * 
     * @throws StockingException Stock quantity already ordered by another user. 
     * 
     */
    public void stocking(String name, String location, 
            int stockLevel, int stockOrdered) throws StockingException {
        log.entering("StockImpl", "stocking", 
                new Object[]{name, location, stockLevel, stockOrdered});
        Long lock = 0L;
        long[] retrecOffset = new long[1];
        String[] criteria = {name, location};
        boolean unlockRequired = true;
        retrecOffset = findBySearchCriteria(criteria);
        // Return the record number
        long recOffset = retrecOffset[0];

        if (recOffset == 0) {
            log.log(Level.INFO, "Problem stocking Manufacturer: " + name + ", " + location);
            String e = "Problem stocking Manufacturer: " + name + ", " + location;
            throw new ServicesException(e);
        }
        try {
            log.log(Level.FINE, "Run by: " + Thread.currentThread().getName());
            Manufacturer manufacturer = getManufacturer(recOffset);
            // Firstly make sure that stock ordered hasn't been set by another user
            if (!manufacturer.getStockOrdered().equals("")) {
                log.log(Level.INFO, "Manufacturer: " + name + ", " + location +
                            " , " + " product: " + manufacturer.getProduct() + 
                            ", stock quantity already ordered by another user.");
                unlockRequired = false;
                throw new ServicesException("Stock quantity already ordered by another user.");
            } else {
                String strStockLevel = "" + stockLevel;
                manufacturer.setStockLevel(strStockLevel);
                String strStockOrdered = "" + stockOrdered;
                manufacturer.setStockOrdered(strStockOrdered);
                String[] manufacturerData = {manufacturer.getDeletedFlag(), manufacturer.getName(), 
                        manufacturer.getLocation(), manufacturer.getProduct(), 
                        manufacturer.getPrice(), manufacturer.getStockLevel(), 
                        manufacturer.getStockOrdered()};
                //Add record number to the locking map
                lock = lockRecord(recOffset);
                //Update record with new stock totals
                updateRecord(recOffset, manufacturerData, lock);
                log.log(Level.INFO, "Manufacturer: " + name + ", " + location +
                        " product: " + manufacturer.getProduct() + 
                        " stock quantity left: " + stockLevel + 
                        ", stock quantity ordered: " + stockOrdered);
            }	
        } catch (ServicesException e) {
            log.log(Level.WARNING, e.getMessage(), e);
            throw new StockingException(e);
        } catch (ManufacturerFileAccessException e) {
            log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } catch (RecordNotFoundException e) {
            log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } catch (SecurityException e) {  
			log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } finally {  
            if (unlockRequired) {
                //Remove record number from the locking map
                unlock(recOffset, lock);
            }
        }
        log.exiting("StockImpl", "stocking");
    }

Save the StockImpl class in the   c:\_Case_Study\src\model directory.

Updating The unstocking() Methodgo to top of page Top

The unstocking() method stub needs to be coded to accept an unstocking amount entered in the Manufacturer GUI. We will have to update the information held in our cache map and also update the physical Manufacturer file held on disk. We must also ensure that the unstocking hasn't already been done by another user, before setting our locks and updating the information.

In not already open, open the StockImpl class in your text editor and cut and paste the above unstocking() method into the StockImpl class overwriting the existing unstocking() method and comments. The unstocking() method can be found near the bottom of the StockImpl class just below the stocking() method.


    /**
     * Unstock the requested amount entered by a user in the GUI.
     *
     * @param name The name of the Manufacturer.
     * @param location The location where the Manufacturer is based.
     * @param stockOrdered The amount of unstocking to do.
     * 
     */
    public void unstocking(String name, String location, int stockOrdered) {
        log.entering("StockImpl", "unstocking", 
                new Object[]{name, location, stockOrdered});
        Long lock = 0L;
        long[] retrecOffset = new long[1];
        String[] criteria = {name, location};
        boolean unlockRequired = true;
        retrecOffset = findBySearchCriteria(criteria);
        // Return the record number
        long recOffset = retrecOffset[0];

        if (recOffset == 0) {
            log.log(Level.INFO, "Problem restocking Manufacturer: " + name + ", " + location);
            String e = "Problem restocking Manufacturer: " + name + ", " + location;
            throw new ServicesException(e);
        }
        try {
            log.log(Level.FINE, "Run by: " + Thread.currentThread().getName());
            Manufacturer manufacturer = getManufacturer(recOffset);
            // Firstly make sure that ordered stock hasn't been cancelled by another user
            if (manufacturer.getStockOrdered().equals("")) {
                log.log(Level.INFO, "Manufacturer: " + name + ", " + location +
                        " , product: " + manufacturer.getProduct() + 
                        " stock quantity ordered, already reset by another user.");
                unlockRequired = false;
            } else {
                //Restock manufacturer and remove stock ordered
                int manStockLevel = 0;
                try {
                    manStockLevel = Integer.parseInt(manufacturer.getStockLevel());
                } catch (NumberFormatException e) {
                    log.log(Level.INFO, "Manufacturer: " + name + ", " + location + 
                            ", " + " stock level was non numeric");
                } finally {
                    manStockLevel = manStockLevel + stockOrdered;
                    String strStockLevel = "" + manStockLevel;
                    manufacturer.setStockLevel(strStockLevel);
                    manufacturer.setStockOrdered("");
                    String[] manufacturerData = {manufacturer.getDeletedFlag(), 
                            manufacturer.getName(), manufacturer.getLocation(), 
                            manufacturer.getProduct(), manufacturer.getPrice(), 
                            manufacturer.getStockLevel(), manufacturer.getStockOrdered()};
                    //Add record number to the locking map
                    lock = lockRecord(recOffset);
                    //Update record with new stock totals
                    updateRecord(recOffset, manufacturerData, lock);
                    log.log(Level.INFO, "Manufacturer: " + name + ", " + location +
                            ", product: " + manufacturer.getProduct() + 
                            ", new Stock Level: " + manufacturer.getStockLevel());
                }
            }
        } catch (ManufacturerFileAccessException e) {
            log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } catch (RecordNotFoundException e) {
            log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } catch (SecurityException e) {  
            log.log(Level.SEVERE, e.getMessage(), e);
            throw new ServicesException(e);
        } finally {  
            if (unlockRequired) {
                //Remove record number from the locking map
                unlock(recOffset, lock);
            }
        }
        log.exiting("StockImpl", "unstocking");
    }

Save the StockImpl class in the   c:\_Case_Study\src\model directory.

Compiling Our Source File With the -cp and -d Options

Open your command line editor:

Change to directory  cd c:\_Case_Study\src\model

Compile StockImpl.java using the java compiler with the -cp and -d options
  javac -cp ..\..\classes -d ..\..\classes StockImpl.java

The following screenshot shows that the StockImpl class compiles fine after we have made the changes.

update StockImpl class

Related Java6 Tutorials

Beginning Java6 - Primitive Variables
Beginning Java6 - Conditional Statements
Objects & Classes - Arrays
Objects & Classes - Class Structure and Syntax
Objects & Classes - Reference Variables
Objects & Classes - Methods
Objects & Classes - Instance Variables & Scope
Objects & Classes - Constructors
Objects & Classes - Static Members
Objects & Classes - Enumerations
OO Concepts - Encapsulation - Getters & Setters
Flow Control - Handling Exceptions
Swing - RMI - Serialization


What's Next?

That concludes the model code for the case study. In the next section we complete the controller code.

<<  Search Functionality                    Controller Part 2  >>

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All the Model Part 2 lessons are listed below. Click a link to go to that lesson.


Model Part 2

Search Functionality

Stock Functionality

Updating stocking() Method

Updating unstocking() Method