diff options
Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java new file mode 100644 index 00000000..f176c331 --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java @@ -0,0 +1,288 @@ +/* + * 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.filters.util; + +import java.io.FilterReader; +import java.io.IOException; +import java.io.Reader; +import java.lang.reflect.Constructor; +import java.lang.reflect.InvocationTargetException; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.Vector; + +import org.apache.tools.ant.AntClassLoader; +import org.apache.tools.ant.BuildException; +import org.apache.tools.ant.Project; +import org.apache.tools.ant.filters.BaseFilterReader; +import org.apache.tools.ant.filters.ChainableReader; +import org.apache.tools.ant.types.AntFilterReader; +import org.apache.tools.ant.types.FilterChain; +import org.apache.tools.ant.types.Parameter; +import org.apache.tools.ant.types.Parameterizable; +import org.apache.tools.ant.types.Path; +import org.apache.tools.ant.util.FileUtils; + +/** + * Process a FilterReader chain. + * + */ +public final class ChainReaderHelper { + + // default buffer size + private static final int DEFAULT_BUFFER_SIZE = 8192; + // CheckStyle:VisibilityModifier OFF - bc + /** + * The primary reader to which the reader chain is to be attached. + */ + public Reader primaryReader; + + /** + * The size of the buffer to be used. + */ + public int bufferSize = DEFAULT_BUFFER_SIZE; + + /** + * Chain of filters + */ + public Vector<FilterChain> filterChains = new Vector<FilterChain>(); + + /** The Ant project */ + private Project project = null; + + // CheckStyle:VisibilityModifier ON + + /** + * Sets the primary reader + * @param rdr the reader object + */ + public void setPrimaryReader(Reader rdr) { + primaryReader = rdr; + } + + /** + * Set the project to work with + * @param project the current project + */ + public void setProject(final Project project) { + this.project = project; + } + + /** + * Get the project + * + * @return the current project + */ + public Project getProject() { + return project; + } + + /** + * Sets the buffer size to be used. Defaults to 8192, + * if this method is not invoked. + * @param size the buffer size to use + */ + public void setBufferSize(int size) { + bufferSize = size; + } + + /** + * Sets the collection of filter reader sets + * + * @param fchain the filter chains collection + */ + public void setFilterChains(Vector<FilterChain> fchain) { + filterChains = fchain; + } + + /** + * Assemble the reader + * @return the assembled reader + * @exception BuildException if an error occurs + */ + public Reader getAssembledReader() throws BuildException { + if (primaryReader == null) { + throw new BuildException("primaryReader must not be null."); + } + + Reader instream = primaryReader; + final int filterReadersCount = filterChains.size(); + final Vector<Object> finalFilters = new Vector<Object>(); + final ArrayList<AntClassLoader> classLoadersToCleanUp = + new ArrayList<AntClassLoader>(); + + for (int i = 0; i < filterReadersCount; i++) { + final FilterChain filterchain = + filterChains.elementAt(i); + final Vector<Object> filterReaders = filterchain.getFilterReaders(); + final int readerCount = filterReaders.size(); + for (int j = 0; j < readerCount; j++) { + finalFilters.addElement(filterReaders.elementAt(j)); + } + } + + final int filtersCount = finalFilters.size(); + + if (filtersCount > 0) { + boolean success = false; + try { + for (int i = 0; i < filtersCount; i++) { + Object o = finalFilters.elementAt(i); + + if (o instanceof AntFilterReader) { + instream = + expandReader((AntFilterReader) finalFilters.elementAt(i), + instream, classLoadersToCleanUp); + } else if (o instanceof ChainableReader) { + setProjectOnObject(o); + instream = ((ChainableReader) o).chain(instream); + setProjectOnObject(instream); + } + } + success = true; + } finally { + if (!success && classLoadersToCleanUp.size() > 0) { + cleanUpClassLoaders(classLoadersToCleanUp); + } + } + } + final Reader finalReader = instream; + return classLoadersToCleanUp.size() == 0 ? finalReader + : new FilterReader(finalReader) { + public void close() throws IOException { + FileUtils.close(in); + cleanUpClassLoaders(classLoadersToCleanUp); + } + protected void finalize() throws Throwable { + try { + close(); + } finally { + super.finalize(); + } + } + }; + } + + /** + * helper method to set the project on an object. + * the reflection setProject does not work for anonymous/protected/private + * classes, even if they have public methods. + */ + private void setProjectOnObject(Object obj) { + if (project == null) { + return; + } + if (obj instanceof BaseFilterReader) { + ((BaseFilterReader) obj).setProject(project); + return; + } + project.setProjectReference(obj); + } + + /** + * Deregisters Classloaders from the project so GC can remove them later. + */ + private static void cleanUpClassLoaders(List<AntClassLoader> loaders) { + for (Iterator<AntClassLoader> it = loaders.iterator(); it.hasNext();) { + it.next().cleanup(); + } + } + + /** + * Read data from the reader and return the + * contents as a string. + * @param rdr the reader object + * @return the contents of the file as a string + * @exception IOException if an error occurs + */ + public String readFully(Reader rdr) + throws IOException { + return FileUtils.readFully(rdr, bufferSize); + } + + /** + * Creates and parameterizes a new FilterReader from a + * <filterreader> element. + * + * @since Ant 1.8.0 + */ + private Reader expandReader(final AntFilterReader filter, + final Reader ancestor, + final List<AntClassLoader> classLoadersToCleanUp) { + final String className = filter.getClassName(); + final Path classpath = filter.getClasspath(); + final Project pro = filter.getProject(); + if (className != null) { + try { + Class<?> clazz = null; + if (classpath == null) { + clazz = Class.forName(className); + } else { + AntClassLoader al = pro.createClassLoader(classpath); + classLoadersToCleanUp.add(al); + clazz = Class.forName(className, true, al); + } + if (clazz != null) { + if (!FilterReader.class.isAssignableFrom(clazz)) { + throw new BuildException(className + " does not extend" + + " java.io.FilterReader"); + } + final Constructor<?>[] constructors = clazz.getConstructors(); + int j = 0; + boolean consPresent = false; + for (; j < constructors.length; j++) { + Class<?>[] types = constructors[j].getParameterTypes(); + if (types.length == 1 + && types[0].isAssignableFrom(Reader.class)) { + consPresent = true; + break; + } + } + if (!consPresent) { + throw new BuildException(className + " does not define" + + " a public constructor" + + " that takes in a Reader" + + " as its single argument."); + } + final Reader[] rdr = {ancestor}; + Reader instream = + (Reader) constructors[j].newInstance((Object[]) rdr); + setProjectOnObject(instream); + if (Parameterizable.class.isAssignableFrom(clazz)) { + final Parameter[] params = filter.getParams(); + ((Parameterizable) instream).setParameters(params); + } + return instream; + } + } catch (final ClassNotFoundException cnfe) { + throw new BuildException(cnfe); + } catch (final InstantiationException ie) { + throw new BuildException(ie); + } catch (final IllegalAccessException iae) { + throw new BuildException(iae); + } catch (final InvocationTargetException ite) { + throw new BuildException(ite); + } + } + // Ant 1.7.1 and earlier ignore <filterreader> without a + // classname attribute, not sure this is a good idea - + // backwards compatibility makes it hard to change, though. + return ancestor; + } +} |