| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 |
| * |
| * https://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.apache.tools.ant.util; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import org.apache.tools.ant.util.FileUtils; |
| |
| /** |
| * Class that delays opening the output file until the first bytes |
| * shall be written or the method {@link #open open} has been invoked |
| * explicitly. |
| * |
| * @since Ant 1.6 |
| */ |
| public class LazyFileOutputStream extends OutputStream { |
| |
| private OutputStream fos; |
| private File file; |
| private boolean append; |
| private boolean alwaysCreate; |
| private boolean opened = false; |
| private boolean closed = false; |
| |
| /** |
| * Creates a stream that will eventually write to the file with |
| * the given name and replace it. |
| * @param name the filename. |
| */ |
| public LazyFileOutputStream(String name) { |
| this(name, false); |
| } |
| |
| /** |
| * Creates a stream that will eventually write to the file with |
| * the given name and optionally append to instead of replacing |
| * it. |
| * @param name the filename. |
| * @param append if true append rather than replace. |
| */ |
| public LazyFileOutputStream(String name, boolean append) { |
| this(new File(name), append); |
| } |
| |
| /** |
| * Creates a stream that will eventually write to the file with |
| * the given name and replace it. |
| * @param f the file to create. |
| */ |
| public LazyFileOutputStream(File f) { |
| this(f, false); |
| } |
| |
| /** |
| * Creates a stream that will eventually write to the file with |
| * the given name and optionally append to instead of replacing |
| * it. |
| * @param file the file to create. |
| * @param append if true append rather than replace. |
| */ |
| public LazyFileOutputStream(File file, boolean append) { |
| this(file, append, false); |
| } |
| |
| /** |
| * Creates a stream that will eventually write to the file with |
| * the given name, optionally append to instead of replacing |
| * it, and optionally always create a file (even if zero length). |
| * @param file the file to create. |
| * @param append if true append rather than replace. |
| * @param alwaysCreate if true create the file even if nothing to write. |
| */ |
| public LazyFileOutputStream(File file, boolean append, |
| boolean alwaysCreate) { |
| this.file = file; |
| this.append = append; |
| this.alwaysCreate = alwaysCreate; |
| } |
| |
| /** |
| * Explicitly open the file for writing. |
| * |
| * <p>Returns silently if the file has already been opened.</p> |
| * @throws IOException if there is an error. |
| */ |
| public void open() throws IOException { |
| ensureOpened(); |
| } |
| |
| /** |
| * Close the file. |
| * @throws IOException if there is an error. |
| */ |
| @Override |
| public synchronized void close() throws IOException { |
| if (alwaysCreate && !closed) { |
| ensureOpened(); |
| } |
| if (opened) { |
| fos.close(); |
| } |
| closed = true; |
| } |
| |
| /** |
| * Delegates to the three-arg version. |
| * @param b the bytearray to write. |
| * @throws IOException if there is a problem. |
| */ |
| @Override |
| public void write(byte[] b) throws IOException { |
| write(b, 0, b.length); |
| } |
| |
| /** |
| * Write part of a byte array. |
| * @param b the byte array. |
| * @param offset write from this index. |
| * @param len the number of bytes to write. |
| * @throws IOException if there is a problem. |
| */ |
| @Override |
| public synchronized void write(byte[] b, int offset, int len) |
| throws IOException { |
| ensureOpened(); |
| fos.write(b, offset, len); |
| } |
| |
| /** |
| * Write a byte. |
| * @param b the byte to write. |
| * @throws IOException if there is a problem. |
| */ |
| @Override |
| public synchronized void write(int b) throws IOException { |
| ensureOpened(); |
| fos.write(b); |
| } |
| |
| private synchronized void ensureOpened() throws IOException { |
| if (closed) { |
| throw new IOException(file + " has already been closed."); |
| } |
| |
| if (!opened) { |
| fos = FileUtils.newOutputStream(file.toPath(), append); |
| opened = true; |
| } |
| } |
| } |