diff options
Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java new file mode 100644 index 00000000..79445bfd --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java @@ -0,0 +1,177 @@ +/* + * 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> + */ + 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; + +} |