| /* |
| * 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 |
| * |
| * http://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.types.resources; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| |
| import org.apache.tools.ant.BuildException; |
| import org.apache.tools.ant.types.ResourceCollection; |
| import org.apache.tools.ant.util.FileUtils; |
| |
| /** |
| * A resource that transforms the content of another resource. |
| * |
| * <p>Wraps around another resource, delegates all queries (except |
| * getSize) to that other resource but transforms stream content |
| * on the fly.</p> |
| * |
| * @since Ant 1.8 |
| */ |
| public abstract class ContentTransformingResource extends ResourceDecorator { |
| |
| private static final int BUFFER_SIZE = 8192; |
| |
| /** no arg constructor */ |
| protected ContentTransformingResource() { |
| } |
| |
| /** |
| * Constructor with another resource to wrap. |
| * @param other the resource to wrap. |
| */ |
| protected ContentTransformingResource(final ResourceCollection other) { |
| super(other); |
| } |
| |
| /** |
| * Get the size of this Resource. |
| * @return the size, as a long, 0 if the Resource does not exist (for |
| * compatibility with java.io.File), or UNKNOWN_SIZE if not known. |
| */ |
| @Override |
| public long getSize() { |
| if (isExists()) { |
| InputStream in = null; |
| try { |
| in = getInputStream(); |
| final byte[] buf = new byte[BUFFER_SIZE]; |
| int size = 0; |
| int readNow; |
| while ((readNow = in.read(buf, 0, buf.length)) > 0) { |
| size += readNow; |
| } |
| return size; |
| } catch (final IOException ex) { |
| throw new BuildException("caught exception while reading " |
| + getName(), ex); |
| } finally { |
| FileUtils.close(in); |
| } |
| } else { |
| return 0; |
| } |
| } |
| |
| /** |
| * Get an InputStream for the Resource. |
| * @return an InputStream containing this Resource's content. |
| * @throws IOException if unable to provide the content of this |
| * Resource as a stream. |
| * @throws UnsupportedOperationException if InputStreams are not |
| * supported for this Resource type. |
| */ |
| @Override |
| public InputStream getInputStream() throws IOException { |
| InputStream in = getResource().getInputStream(); |
| if (in != null) { |
| in = wrapStream(in); |
| } |
| return in; |
| } |
| |
| /** |
| * Get an OutputStream for the Resource. |
| * @return an OutputStream to which content can be written. |
| * @throws IOException if unable to provide the content of this |
| * Resource as a stream. |
| * @throws UnsupportedOperationException if OutputStreams are not |
| * supported for this Resource type. |
| */ |
| @Override |
| public OutputStream getOutputStream() throws IOException { |
| OutputStream out = getResource().getOutputStream(); |
| if (out != null) { |
| out = wrapStream(out); |
| } |
| return out; |
| } |
| |
| /** |
| * Suppress FileProvider, re-implement Appendable |
| */ |
| @Override |
| public <T> T as(final Class<T> clazz) { |
| if (Appendable.class.isAssignableFrom(clazz)) { |
| if (isAppendSupported()) { |
| final Appendable a = |
| getResource().as(Appendable.class); |
| if (a != null) { |
| return clazz.cast(new Appendable() { |
| public OutputStream getAppendOutputStream() |
| throws IOException { |
| OutputStream out = a.getAppendOutputStream(); |
| if (out != null) { |
| out = wrapStream(out); |
| } |
| return out; |
| } |
| }); |
| } |
| } |
| return null; |
| } |
| |
| return FileProvider.class.isAssignableFrom(clazz) |
| ? null : getResource().as(clazz); |
| } |
| |
| /** |
| * Learn whether the transformation performed allows appends. |
| * |
| * <p>In general compressed outputs will become invalid if they |
| * are appended to, for example.</p> |
| * |
| * <p>This implementations returns false.</p> |
| * |
| * @return boolean false |
| */ |
| protected boolean isAppendSupported() { |
| return false; |
| } |
| |
| /** |
| * Get a content-filtering/transforming InputStream. |
| * |
| * @param in InputStream to wrap, will never be null. |
| * @return a compressed InputStream. |
| * @throws IOException if there is a problem. |
| */ |
| protected abstract InputStream wrapStream(InputStream in) |
| throws IOException; |
| |
| /** |
| * Get a content-filtering/transforming OutputStream. |
| * |
| * @param out OutputStream to wrap, will never be null. |
| * @return a compressed OutputStream. |
| * @throws IOException if there is a problem. |
| */ |
| protected abstract OutputStream wrapStream(OutputStream out) |
| throws IOException; |
| |
| } |