001 /* 002 $Id: ReaderSource.java 1082 2004-04-19 07:29:47Z cpoirier $ 003 004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved. 005 006 Redistribution and use of this software and associated documentation 007 ("Software"), with or without modification, are permitted provided 008 that the following conditions are met: 009 010 1. Redistributions of source code must retain copyright 011 statements and notices. Redistributions must also contain a 012 copy of this document. 013 014 2. Redistributions in binary form must reproduce the 015 above copyright notice, this list of conditions and the 016 following disclaimer in the documentation and/or other 017 materials provided with the distribution. 018 019 3. The name "groovy" must not be used to endorse or promote 020 products derived from this Software without prior written 021 permission of The Codehaus. For written permission, 022 please contact info@codehaus.org. 023 024 4. Products derived from this Software may not be called "groovy" 025 nor may "groovy" appear in their names without prior written 026 permission of The Codehaus. "groovy" is a registered 027 trademark of The Codehaus. 028 029 5. Due credit should be given to The Codehaus - 030 http://groovy.codehaus.org/ 031 032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS 033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 043 OF THE POSSIBILITY OF SUCH DAMAGE. 044 045 */ 046 047 package org.codehaus.groovy.control.io; 048 049 import java.io.IOException; 050 import java.io.Reader; 051 052 import org.codehaus.groovy.control.HasCleanup; 053 import org.codehaus.groovy.control.Janitor; 054 055 056 /** 057 * An interface for things that can supply (and resupply) a Reader 058 * on a source stream. 059 * 060 * @author <a href="mailto:cpoirier@dreaming.org">Chris Poirier</a> 061 * 062 * @version $Id: ReaderSource.java 1082 2004-04-19 07:29:47Z cpoirier $ 063 */ 064 065 public interface ReaderSource extends HasCleanup 066 { 067 068 /** 069 * Returns a new Reader on the underlying source object. Returns 070 * null if the source can't be reopened. 071 */ 072 073 Reader getReader() throws IOException; 074 075 076 077 /** 078 * Returns true if the source can be restarted (ie. if getReader() 079 * will return non-null on subsequent calls. 080 */ 081 082 boolean canReopenSource(); 083 084 085 086 /** 087 * Returns a line from the source, or null, if unavailable. If 088 * you supply a Janitor, resources will be cached. 089 */ 090 091 String getLine( int lineNumber, Janitor janitor ); 092 093 094 095 /** 096 * Cleans up any cached resources used by getLine(). 097 */ 098 099 void cleanup(); 100 101 }