implement ContentResolver

ContentUris.java and UriMatcher.java are copied from AOSP

src/api-impl/android/content/ContentUris.java

@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.content;
+
+import java.util.List;
+
+import android.net.Uri;
+
+/**
+* Utility methods useful for working with {@link android.net.Uri} objects
+* that use the "content" (content://) scheme.
+*
+*<p>
+*   Content URIs have the syntax
+*</p>
+*<p>
+*   <code>content://<em>authority</em>/<em>path</em>/<em>id</em></code>
+*</p>
+*<dl>
+*   <dt>
+*       <code>content:</code>
+*   </dt>
+*   <dd>
+*       The scheme portion of the URI. This is always set to {@link
+*       android.content.ContentResolver#SCHEME_CONTENT ContentResolver.SCHEME_CONTENT} (value
+*       <code>content://</code>).
+*   </dd>
+*   <dt>
+*       <em>authority</em>
+*   </dt>
+*   <dd>
+*       A string that identifies the entire content provider. All the content URIs for the provider
+*       start with this string. To guarantee a unique authority, providers should consider
+*       using an authority that is the same as the provider class' package identifier.
+*   </dd>
+*   <dt>
+*       <em>path</em>
+*   </dt>
+*   <dd>
+*       Zero or more segments, separated by a forward slash (<code>/</code>), that identify
+*       some subset of the provider's data. Most providers use the path part to identify
+*       individual tables. Individual segments in the path are often called
+*       &quot;directories&quot; although they do not refer to file directories. The right-most
+*       segment in a path is often called a &quot;twig&quot;
+*   </dd>
+*   <dt>
+*       <em>id</em>
+*   </dt>
+*   <dd>
+*       A unique numeric identifier for a single row in the subset of data identified by the
+*       preceding path part. Most providers recognize content URIs that contain an id part
+*       and give them special handling. A table that contains a column named <code>_ID</code>
+*       often expects the id part to be a particular value for that column.
+*   </dd>
+*</dl>
+*
+*/
+public class ContentUris {
+
+	/**
+	 * Converts the last path segment to a long.
+	 *
+	 * <p>This supports a common convention for content URIs where an ID is
+	 * stored in the last segment.
+	 *
+	 * @throws UnsupportedOperationException if this isn't a hierarchical URI
+	 * @throws NumberFormatException if the last segment isn't a number
+	 *
+	 * @return the long conversion of the last segment or -1 if the path is
+	 *  empty
+	 */
+	public static long parseId(Uri contentUri) {
+		String last = contentUri.getLastPathSegment();
+		return last == null ? -1 : Long.parseLong(last);
+	}
+
+	/**
+	 * Appends the given ID to the end of the path.
+	 *
+	 * @param builder to append the ID to
+	 * @param id to append
+	 *
+	 * @return the given builder
+	 */
+	public static Uri.Builder appendId(Uri.Builder builder, long id) {
+		return builder.appendEncodedPath(String.valueOf(id));
+	}
+
+	/**
+	 * Appends the given ID to the end of the path.
+	 *
+	 * @param contentUri to start with
+	 * @param id to append
+	 *
+	 * @return a new URI with the given ID appended to the end of the path
+	 */
+	public static Uri withAppendedId(Uri contentUri, long id) {
+		return appendId(contentUri.buildUpon(), id).build();
+	}
+
+	/**
+	 * Removes any ID from the end of the path.
+	 *
+	 * @param contentUri that ends with an ID
+	 * @return a new URI with the ID removed from the end of the path
+	 * @throws IllegalArgumentException when the given URI has no ID to remove
+	 *             from the end of the path
+	 */
+	public static Uri removeId(Uri contentUri) {
+		// Verify that we have a valid ID to actually remove
+		final String last = contentUri.getLastPathSegment();
+		if (last == null) {
+			throw new IllegalArgumentException("No path segments to remove");
+		} else {
+			Long.parseLong(last);
+		}
+
+		final List<String> segments = contentUri.getPathSegments();
+		final Uri.Builder builder = contentUri.buildUpon();
+		builder.path(null);
+		for (int i = 0; i < segments.size() - 1; i++) {
+			builder.appendPath(segments.get(i));
+		}
+		return builder.build();
+	}
+}