| /* |
| * 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.ByteArrayInputStream; |
| import java.io.IOException; |
| import org.apache.bcel.classfile.ClassParser; |
| import org.apache.bcel.classfile.ConstantValue; |
| import org.apache.bcel.classfile.Field; |
| import org.apache.bcel.classfile.JavaClass; |
| |
| // CheckStyle:HideUtilityClassConstructorCheck OFF - bc |
| /** |
| * Helper class that filters constants from a Java Class |
| * |
| */ |
| public final class JavaClassHelper { |
| /** System specific line separator. */ |
| private static final String LS = System.getProperty("line.separator"); |
| |
| /** |
| * Get the constants declared in a file as name=value |
| * |
| * @param bytes the class as a array of bytes |
| * @return a StringBuffer contains the name=value pairs |
| * @exception IOException if an error occurs |
| */ |
| public static StringBuffer getConstants(byte[] bytes) |
| throws IOException { |
| final StringBuffer sb = new StringBuffer(); |
| final ByteArrayInputStream bis = new ByteArrayInputStream(bytes); |
| final ClassParser parser = new ClassParser(bis, ""); |
| final JavaClass javaClass = parser.parse(); |
| final Field[] fields = javaClass.getFields(); |
| for (int i = 0; i < fields.length; i++) { |
| final Field field = fields[i]; |
| if (field != null) { |
| final ConstantValue cv = field.getConstantValue(); |
| if (cv != null) { |
| String cvs = cv.toString(); |
| //Remove start and end quotes if field is a String |
| if (cvs.startsWith("\"") && cvs.endsWith("\"")) { |
| cvs = cvs.substring(1, cvs.length() - 1); |
| } |
| sb.append(field.getName()); |
| sb.append('='); |
| sb.append(cvs); |
| sb.append(LS); |
| } |
| } |
| } |
| return sb; |
| } |
| } |