GREAT PACKAGE RESHUFFLE: Everything is now organised into frontend, backend and common (to frontend and backend) packages. Things may have been broken. Doc refresh.

1 files changed, 80 insertions, 0 deletions

diff --git a/src/uk/org/ury/backend/database/DatabaseItem.java b/src/uk/org/ury/backend/database/DatabaseItem.java
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+++ b/src/uk/org/ury/backend/database/DatabaseItem.java
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+package uk.org.ury.backend.database;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import uk.org.ury.backend.database.exceptions.MissingPropertyException;
+
+/**
+ * An abstract class presenting a template for objects serving as a data
+ * structure for collections of properties retrieved from a SQL database.
+ * 
+ * @param E
+ *            The enumeration type used as the property list.
+ * 
+ * @param T
+ *            The type of datum stored for each property.
+ * 
+ * @author Matt Windsor
+ */
+public abstract class DatabaseItem<E, T> {
+    private Map<E, T> properties;
+
+    /**
+     * Construct a new item from an existing list of properties.
+     * 
+     * @param properties
+     *            The map of properties that the new item will inherit.
+     */
+    public DatabaseItem(Map<E, T> properties) {
+	this.properties = properties;
+    }
+
+    /**
+     * Check whether a property has been set in the item.
+     * 
+     * @return true if the property has been set; false otherwise.
+     */
+
+    public boolean has(E property) {
+	return properties.containsKey(property);
+    }
+
+    /**
+     * Query this item for a property.
+     * 
+     * @param property
+     *            The property to query.
+     * 
+     * @return The property, if it exists.
+     * 
+     * @throws MissingPropertyException
+     *             if the property does not exist.
+     */
+    public T get(E property) throws MissingPropertyException {
+	if (properties.containsKey(property))
+	    return properties.get(property);
+	else
+	    throw new MissingPropertyException(property.toString());
+    }
+
+    /**
+     * Retrieve a map of string representations of the properties.
+     * 
+     * This relies on E and T having meaningful toString methods.
+     * 
+     * @return a list of lines representing the response.
+     */
+    public Map<String, String> asResponse() {
+	// TODO: Fan out implementation details into separate class
+	Map<String, String> response = new HashMap<String, String>();
+
+	for (E property : properties.keySet()) {
+	    if (properties.get(property) != null)
+		response.put(property.toString(), properties.get(property)
+			.toString());
+	}
+
+	return response;
+    }
+}