1 files changed, 144 insertions, 0 deletions
diff --git a/src/uk/org/ury/common/library/LibraryUtils.java b/src/uk/org/ury/common/library/LibraryUtils.java
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+++ b/src/uk/org/ury/common/library/LibraryUtils.java
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+/**
+ * 
+ */
+package uk.org.ury.common.library;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import uk.org.ury.backend.database.DatabaseDriver;
+import uk.org.ury.backend.database.exceptions.QueryFailureException;
+import uk.org.ury.common.library.exceptions.EmptySearchException;
+import uk.org.ury.common.library.item.LibraryItem;
+import uk.org.ury.common.library.item.LibraryItemProperty;
+
+
+
+/**
+ * A set of common utility routines to facilitate the extraction of 
+ * library items from the library areas of the URY database. 
+ * 
+ * @author  Matt Windsor
+ */
+
+public class LibraryUtils
+{ 
+  /**
+   * Perform a library search.
+   * 
+   * @param db      The database to query.
+   * 
+   * @param search  The search fragment to include in the search.
+   *                Can be empty or null.
+   *                
+   * @throws        IllegalArgumentException if the search term is 
+   *                are null.
+   *                
+   * @throws        QueryFailureException if the database backend 
+   *                yielded an error while executing the search 
+   *                query.
+   *                
+   * @throws        EmptySearchException if the search term is 
+   *                empty (to be handled as a user error).
+   *                
+   * @return        a list of LibraryItems matching the search terms.
+   */
+  
+  public static List<LibraryItem>
+  search (DatabaseDriver db, String search)
+  throws QueryFailureException, EmptySearchException
+  {
+    if (db == null)
+      throw new IllegalArgumentException ("Database handle is null.");
+
+    if (search == null)
+      throw new IllegalArgumentException ("Search string is null.");
+
+    List<LibraryItem> results = new ArrayList<LibraryItem> ();
+    
+    
+    // Return empty set if the search term is null.
+    
+    if (search.equals(""))
+    	throw new EmptySearchException ();
+    
+    
+    ResultSet rs = null;
+
+    Object[] params = {"%" + search + "%", "%" + search + "%", "%" + search + "%"};
+    
+    try
+      {
+        rs = db.executeQuery (
+            "SELECT r.title AS album, t.title,"
+            + " t.artist, recordlabel AS label, status, media AS medium, format,"
+            + " datereleased, EXTRACT(EPOCH FROM dateadded) as dateadded,"
+            + " EXTRACT(EPOCH FROM datetime_lastedit) AS dateedited,"
+            + " shelfletter, shelfnumber, cdid, digitised, clean"
+            + " FROM rec_record AS r"
+            + " INNER JOIN rec_track AS t ON (r.recordid = t.recordid)"
+            + " WHERE t.title ILIKE ?"
+            + " OR t.artist ILIKE ?"
+            + " OR r.title ILIKE ?"
+            + " ORDER BY digitised DESC, medium ASC, r.title ASC,"
+            + " t.artist ASC, t.title ASC;", params, 50);
+      }
+    catch (SQLException e)
+      {
+        throw new QueryFailureException (e.getMessage ());
+      }
+    
+    try
+      {
+        while (rs.next ())
+          {
+            results.add (translateRow (rs));
+          }
+      }
+    catch (SQLException e)
+      { 
+        throw new QueryFailureException (e.getMessage ());
+      }
+  
+    return results;
+  }
+  
+  
+  /**
+   * Translate a row retrieved from the database into a LibraryItem.
+   * 
+   * @param rs  The result-set, or database cursor, pointing to the 
+   *            row to translate.
+   *            
+   * @return    A new LibraryItem containing the properties extracted 
+   *            from the translated row.
+   */
+  
+  private static LibraryItem
+  translateRow (ResultSet rs)
+  {
+    // Translate SQL columns into a list of properties.
+            
+    Map<LibraryItemProperty, String> properties = new HashMap<LibraryItemProperty, String> ();
+            
+    for (LibraryItemProperty p : LibraryItemProperty.values ())
+      {
+        try
+          {
+            properties.put (p, rs.getString (p.sql));
+          }
+        catch (SQLException e)
+          {
+            // Ignore this, as it is almost certainly just a non-existent 
+            // property.
+          }
+      }
+    
+  
+    return new LibraryItem (properties);
+  }
+}