1bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2006 The Guava Authors 3bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * 4bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Licensed under the Apache License, Version 2.0 (the "License"); 5bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * you may not use this file except in compliance with the License. 6bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * You may obtain a copy of the License at 7bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * 8bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * http://www.apache.org/licenses/LICENSE-2.0 9bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * 10bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Unless required by applicable law or agreed to in writing, software 11bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * distributed under the License is distributed on an "AS IS" BASIS, 12bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * See the License for the specific language governing permissions and 14bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * limitations under the License. 15bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor */ 16bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 17bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnorpackage com.google.common.io; 18bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 19bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnorimport java.io.Closeable; 20bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnorimport java.io.Flushable; 21bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnorimport java.io.IOException; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.io.Writer; 23bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 24bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor/** 25bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Writer that places all output on an {@link Appendable} target. If the target 26bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * is {@link Flushable} or {@link Closeable}, flush()es and close()s will also 27bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * be delegated to the target. 28bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * 29bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * @author Alan Green 30bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * @author Sebastian Kanthak 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 1.0 32bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor */ 33bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnorclass AppendableWriter extends Writer { 34bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor private final Appendable target; 35bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor private boolean closed; 36bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 37bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor /** 38bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Creates a new writer that appends everything it writes to {@code target}. 39bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * 40bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * @param target target to which to append output 41bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor */ 42bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor AppendableWriter(Appendable target) { 43bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor this.target = target; 44bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 45bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 46bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor /* 47bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Abstract methods from Writer 48bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor */ 49bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 50bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void write(char cbuf[], int off, int len) 51bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor throws IOException { 52bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 53bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor // It turns out that creating a new String is usually as fast, or faster 54bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor // than wrapping cbuf in a light-weight CharSequence. 55bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(new String(cbuf, off, len)); 56bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 57bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 58bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void flush() throws IOException { 59bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 60bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor if (target instanceof Flushable) { 61bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor ((Flushable) target).flush(); 62bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 63bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 64bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 65bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void close() throws IOException { 66bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor this.closed = true; 67bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor if (target instanceof Closeable) { 68bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor ((Closeable) target).close(); 69bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 70bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 71bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 72bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor /* 73bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * Override a few functions for performance reasons to avoid creating 74bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor * unnecessary strings. 75bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor */ 76bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 77bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void write(int c) throws IOException { 78bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 79bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append((char) c); 80bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 81bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 82bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void write(String str) throws IOException { 83bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 84bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(str); 85bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 86bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 87bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public void write(String str, int off, int len) throws IOException { 88bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 89bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor // tricky: append takes start, end pair... 90bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(str, off, off + len); 91bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 92bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 93bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public Writer append(char c) throws IOException { 94bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 95bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(c); 96bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor return this; 97bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 98bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 99bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public Writer append(CharSequence charSeq) throws IOException { 100bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 101bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(charSeq); 102bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor return this; 103bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 104bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 105bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor @Override public Writer append(CharSequence charSeq, int start, int end) 106bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor throws IOException { 107bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor checkNotClosed(); 108bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor target.append(charSeq, start, end); 109bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor return this; 110bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 111bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor 112bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor private void checkNotClosed() throws IOException { 113bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor if (closed) { 114bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor throw new IOException("Cannot write to a closed writer."); 115bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 116bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor } 117bfe2dd089341dcb4c1fb65a5b6b077ad0ebbf6dcDan Egnor} 118