| /* |
| * 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; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import org.apache.tools.ant.BuildException; |
| |
| |
| /** |
| * Assembles the constants declared in a Java class in |
| * <code>key1=value1(line separator)key2=value2</code> |
| * format. |
| *<p> |
| * Notes: |
| * <ol> |
| * <li>This filter uses the BCEL external toolkit. |
| * <li>This assembles only those constants that are not created |
| * using the syntax <code>new whatever()</code> |
| * <li>This assembles constants declared using the basic datatypes |
| * and String only.</li> |
| * <li>The access modifiers of the declared constants do not matter.</li> |
| *</ol> |
| * Example:<br> |
| * <pre><classconstants/></pre> |
| * Or: |
| * <pre><filterreader |
| * classname="org.apache.tools.ant.filters.ClassConstants"/></pre> |
| */ |
| public final class ClassConstants |
| extends BaseFilterReader |
| implements ChainableReader { |
| /** Data that must be read from, if not null. */ |
| private String queuedData = null; |
| |
| /** Helper Class to be invoked via reflection. */ |
| private static final String JAVA_CLASS_HELPER = |
| "org.apache.tools.ant.filters.util.JavaClassHelper"; |
| |
| /** |
| * Constructor for "dummy" instances. |
| * |
| * @see BaseFilterReader#BaseFilterReader() |
| */ |
| public ClassConstants() { |
| super(); |
| } |
| |
| /** |
| * Creates a new filtered reader. The contents of the passed-in reader |
| * are expected to be the name of the class from which to produce a |
| * list of constants. |
| * |
| * @param in A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| */ |
| public ClassConstants(final Reader in) { |
| super(in); |
| } |
| |
| /** |
| * Reads and assembles the constants declared in a class file. |
| * |
| * @return the next character in the list of constants, or -1 |
| * if the end of the resulting stream has been reached |
| * |
| * @exception IOException if the underlying stream throws an IOException |
| * during reading, or if the constants for the specified class cannot |
| * be read (for example due to the class not being found). |
| */ |
| public int read() throws IOException { |
| |
| int ch = -1; |
| |
| if (queuedData != null && queuedData.length() == 0) { |
| queuedData = null; |
| } |
| |
| if (queuedData != null) { |
| ch = queuedData.charAt(0); |
| queuedData = queuedData.substring(1); |
| if (queuedData.length() == 0) { |
| queuedData = null; |
| } |
| } else { |
| final String clazz = readFully(); |
| if (clazz == null || clazz.length() == 0) { |
| ch = -1; |
| } else { |
| final byte[] bytes = clazz.getBytes("ISO-8859-1"); |
| try { |
| final Class javaClassHelper = |
| Class.forName(JAVA_CLASS_HELPER); |
| if (javaClassHelper != null) { |
| final Class[] params = { |
| byte[].class |
| }; |
| final Method getConstants = |
| javaClassHelper.getMethod("getConstants", params); |
| final Object[] args = { |
| bytes |
| }; |
| // getConstants is a static method, no need to |
| // pass in the object |
| final StringBuffer sb = (StringBuffer) |
| getConstants.invoke(null, args); |
| if (sb.length() > 0) { |
| queuedData = sb.toString(); |
| return read(); |
| } |
| } |
| } catch (NoClassDefFoundError ex) { |
| throw ex; |
| } catch (RuntimeException ex) { |
| throw ex; |
| } catch (InvocationTargetException ex) { |
| Throwable t = ex.getTargetException(); |
| if (t instanceof NoClassDefFoundError) { |
| throw (NoClassDefFoundError) t; |
| } |
| if (t instanceof RuntimeException) { |
| throw (RuntimeException) t; |
| } |
| throw new BuildException(t); |
| } catch (Exception ex) { |
| throw new BuildException(ex); |
| } |
| } |
| } |
| return ch; |
| } |
| |
| /** |
| * Creates a new ClassConstants using the passed in |
| * Reader for instantiation. |
| * |
| * @param rdr A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| * |
| * @return a new filter based on this configuration, but filtering |
| * the specified reader |
| */ |
| public Reader chain(final Reader rdr) { |
| ClassConstants newFilter = new ClassConstants(rdr); |
| return newFilter; |
| } |
| } |