001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.configuration2.io; 018 019import java.io.IOException; 020import java.io.Reader; 021import java.io.Writer; 022 023import org.apache.commons.configuration2.ex.ConfigurationException; 024 025/** 026 * <p> 027 * Definition of an interface to be implemented by objects which know how to 028 * read and write themselves from or to a character stream. 029 * </p> 030 * <p> 031 * This interface is implemented by special implementations of the 032 * {@code Configuration} interface which are associated with a file. It demands 033 * only basic methods for doing I/O based on character stream objects. Based on 034 * these methods it is possible to implement other methods which operate on 035 * files, file names, URLs, etc. 036 * </p> 037 * <p> 038 * <strong>Note that the methods defined by this interface are not intended to 039 * be called directly by client code!</strong> Rather, they are used internally 040 * when doing I/O operations with a {@link FileHandler}. A {@code FileHandler} 041 * supports additional functionality (e.g. it evaluates some additional 042 * interfaces the {@code FileBased} object may implement); this functionality 043 * is not available on a direct method invocation, so this may lead to 044 * unpredictable results. 045 * </p> 046 * 047 */ 048public interface FileBased 049{ 050 /** 051 * Reads the content of this object from the given reader. 052 * <strong>Client code should not call this method directly, but use a 053 * {@code FileHandler} for reading data.</strong> 054 * 055 * @param in the reader 056 * @throws IOException if an I/O error occurs 057 * @throws ConfigurationException if a non-I/O related problem occurs, e.g. 058 * the data read does not have the expected format 059 */ 060 void read(Reader in) throws ConfigurationException, IOException; 061 062 /** 063 * Writes the content of this object to the given writer. 064 * <strong>Client code should not call this method directly, but use a 065 * {@code FileHandler} for writing data.</strong> 066 * 067 * @param out the writer 068 * @throws IOException if an I/O error occurs 069 * @throws ConfigurationException if a non-I/O related problem occurs, e.g. 070 * the data read does not have the expected format 071 */ 072 void write(Writer out) throws ConfigurationException, IOException; 073}