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SmallBookServiceServantData.javaAPI DocExample2984Fri Oct 11 10:25:00 BST 2002ora.jwsnut.chapter6.smallbookservice

SmallBookServiceServantData

public class SmallBookServiceServantData extends Object
A class that loads the data for the small book service

Fields Summary
private static HashMap
bookAuthorMap
The author data in the form of a HashMap, created when it is first requested.
private static String[]
bookTitles
List of book titles.
private static byte[]
buffer
Buffer used when reading image data
private static ByteArrayOutputStream
os
Stream used when reading image data
Constructors Summary
Methods Summary
public static java.lang.StringgetBookAuthor(java.lang.String title)
Gets the author name for a book with a given title.

        loadData();
        return (String)bookAuthorMap.get(title.trim().toUpperCase());
    
public static java.lang.String[]getBookTitles()
Gets a list of all known books.

        loadData();
        return bookTitles;
    
private static voidloadData()
Loads the book data from information contained in the booklist.txt file.

        if (bookAuthorMap == null) {
            
            // First request - create the data
            bookAuthorMap = new HashMap();
            ArrayList list = new ArrayList();

            try {
                buffer = new byte[1024];
                os = new ByteArrayOutputStream();                
                InputStream is = 
                    SmallBookServiceServantData.class.getResourceAsStream("booklist.txt");
                BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                String line;
                while ((line = reader.readLine()) != null) {
                    StringTokenizer st = new StringTokenizer(line, "!");
                    if (st.countTokens() == 2) {
                        String title = st.nextToken();
                        String canonicalTitle = title.trim().toUpperCase();
                        String author = st.nextToken();
                        
                        // Store the author name
                        bookAuthorMap.put(canonicalTitle, author);
                        
                        // Add a new book title
                        list.add(title);
                    }
                }
                
                bookTitles = new String[list.size()];
                list.toArray(bookTitles);
            } catch (Exception ex) {
                // Just return an empty or partial list                
                ex.printStackTrace();
            }
        }