| /* |
| * Copyright 2003-2007 the original author or authors. |
| * |
| * 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 org.codehaus.groovy.control.io; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| import org.codehaus.groovy.control.HasCleanup; |
| import org.codehaus.groovy.control.Janitor; |
| |
| /** |
| * An interface for things that can supply (and potentially resupply) a Reader |
| * on a source stream. |
| * |
| * @author <a href="mailto:cpoirier@dreaming.org">Chris Poirier</a> |
| * |
| * @version $Id$ |
| */ |
| public interface ReaderSource extends HasCleanup { |
| /** |
| * Returns a new Reader on the underlying source object. Returns |
| * null if the source can't be reopened. |
| * @throws java.io.IOException if there was an error opening for stream |
| * @return the reader to the resource |
| */ |
| Reader getReader() throws IOException; |
| |
| /** |
| * Returns true if the source can be restarted (ie. if getReader() |
| * will return non-null on subsequent calls. |
| * @return true if the resource can be reopened for reading |
| */ |
| boolean canReopenSource(); |
| |
| /** |
| * Returns a line from the source, or null, if unavailable. If |
| * you supply a Janitor, resources will be cached. |
| * @param lineNumber the number of the line of interest |
| * @param janitor helper to clean up afterwards |
| * @return the line of interest |
| */ |
| String getLine( int lineNumber, Janitor janitor ); |
| |
| /** |
| * Cleans up any cached resources used by getLine(). |
| */ |
| void cleanup(); |
| } |