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Semester 1/Programming 1/Java/examples/projects/chapter14/address-book-v1g/AddressBook.java

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+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import java.util.TreeSet;
+
+/**
+ * A class to maintain an arbitrary number of contact details.
+ * Details are indexed by both name and phone number.
+ * 
+ * @author David J. Barnes and Michael Kölling.
+ * @version 2016.02.29
+ */
+public class AddressBook
+{
+    // Storage for an arbitrary number of details.
+    private TreeMap<String, ContactDetails> book;
+    private int numberOfEntries;
+
+    /**
+     * Perform any initialization for the address book.
+     */
+    public AddressBook()
+    {
+        book = new TreeMap<>();
+        numberOfEntries = 0;
+    }
+    
+    /**
+     * Look up a name or phone number and return the
+     * corresponding contact details.
+     * @param key The name or number to be looked up.
+     * @return The details corresponding to the key.
+     */
+    public ContactDetails getDetails(String key)
+    {
+        return book.get(key);
+    }
+
+    /**
+     * Return whether or not the current key is in use.
+     * @param key The name or number to be looked up.
+     * @return true if the key is in use, false otherwise.
+     */
+    public boolean keyInUse(String key)
+    {
+        return book.containsKey(key);
+    }
+
+    /**
+     * Add a new set of details to the address book.
+     * @param details The details to associate with the person.
+     */
+    public void addDetails(ContactDetails details)
+    {
+        book.put(details.getName(), details);
+        book.put(details.getPhone(), details);
+        numberOfEntries++;
+    }
+    
+    /**
+     * Change the details previously stored under the given key.
+     * @param oldKey One of the keys used to store the details.
+     * @param details The replacement details.
+     */
+    public void changeDetails(String oldKey,
+                              ContactDetails details)
+    {
+        removeDetails(oldKey);
+        addDetails(details);
+    }
+    
+    /**
+     * Search for all details stored under a key that starts with
+     * the given prefix.
+     * @param keyPrefix The key prefix to search on.
+     * @return An array of those details that have been found.
+     */
+    public ContactDetails[] search(String keyPrefix)
+    {
+        // Build a list of the matches.
+        List<ContactDetails> matches = new LinkedList<>();
+        // Find keys that are equal-to or greater-than the prefix.
+        SortedMap<String, ContactDetails> tail = book.tailMap(keyPrefix);
+        Iterator<String> it = tail.keySet().iterator();
+        // Stop when we find a mismatch.
+        boolean endOfSearch = false;
+        while(!endOfSearch && it.hasNext()) {
+            String key = it.next();
+            if(key.startsWith(keyPrefix)) {
+                matches.add(book.get(key));
+            }
+            else {
+                endOfSearch = true;
+            }
+        }
+        ContactDetails[] results = new ContactDetails[matches.size()];
+        matches.toArray(results);
+        return results;
+    }
+
+    /**
+     * Return the number of entries currently in the
+     * address book.
+     * @return The number of entries.
+     */
+    public int getNumberOfEntries()
+    {
+        return numberOfEntries;
+    }
+
+    /**
+     * Remove an entry with the given key from the address book.
+     * @param key One of the keys of the entry to be removed.
+     */
+    public void removeDetails(String key)
+    {
+        ContactDetails details = book.get(key);
+        book.remove(details.getName());
+        book.remove(details.getPhone());
+        numberOfEntries--;
+    }
+
+    /**
+     * Return all the contact details, sorted according
+     * to the sort order of the ContactDetails class.
+     * @return A sorted list of the details.
+     */
+    public String listDetails()
+    {
+        // Because each entry is stored under two keys, it is
+        // necessary to build a set of the ContactDetails. This
+        // eliminates duplicates.
+        StringBuilder allEntries = new StringBuilder();
+        Set<ContactDetails> sortedDetails = new TreeSet<>(book.values());
+        for(ContactDetails details : sortedDetails) {
+            allEntries.append(details).append("\n\n");
+        }
+        return allEntries.toString();
+    }
+}