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.io.output; 018 019import java.io.IOException; 020import java.io.Writer; 021import java.util.function.Supplier; 022 023/** 024 * Always throws an {@link IOException} from all {@link Writer} methods. 025 * <p> 026 * This class is mostly useful for testing error handling in code that uses a writer. 027 * </p> 028 * 029 * @since 2.0 030 */ 031public class BrokenWriter extends Writer { 032 033 /** 034 * The singleton instance. 035 * 036 * @since 2.12.0 037 */ 038 public static final BrokenWriter INSTANCE = new BrokenWriter(); 039 040 /** 041 * A supplier for the exception that is thrown by all methods of this class. 042 */ 043 private final Supplier<IOException> exceptionSupplier; 044 045 /** 046 * Constructs a new writer that always throws an {@link IOException}. 047 */ 048 public BrokenWriter() { 049 this(() -> new IOException("Broken writer")); 050 } 051 052 /** 053 * Constructs a new writer that always throws the given exception. 054 * 055 * @param exception the exception to be thrown. 056 */ 057 public BrokenWriter(final IOException exception) { 058 this(() -> exception); 059 } 060 061 /** 062 * Constructs a new writer that always throws an {@link IOException}. 063 * 064 * @param exceptionSupplier a supplier for the exception to be thrown. 065 * @since 2.12.0 066 */ 067 public BrokenWriter(final Supplier<IOException> exceptionSupplier) { 068 this.exceptionSupplier = exceptionSupplier; 069 } 070 071 /** 072 * Throws the configured exception. 073 * 074 * @throws IOException always thrown 075 */ 076 @Override 077 public void close() throws IOException { 078 throw exceptionSupplier.get(); 079 } 080 081 /** 082 * Throws the configured exception. 083 * 084 * @throws IOException always thrown 085 */ 086 @Override 087 public void flush() throws IOException { 088 throw exceptionSupplier.get(); 089 } 090 091 /** 092 * Throws the configured exception. 093 * 094 * @param cbuf ignored 095 * @param off ignored 096 * @param len ignored 097 * @throws IOException always thrown 098 */ 099 @Override 100 public void write(final char[] cbuf, final int off, final int len) throws IOException { 101 throw exceptionSupplier.get(); 102 } 103 104}