code: /**
   * This file is part of Eclipse Steady.
   *
   * Licensed 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.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.java;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.util.Map;
  import java.util.Set;
  import java.util.TreeMap;
  
  import org.apache.logging.log4j.Logger;
  import org.eclipse.steady.Construct;
  import org.eclipse.steady.ConstructId;
  import org.eclipse.steady.FileAnalysisException;
  import org.eclipse.steady.FileAnalyzer;
  import org.eclipse.steady.java.monitor.ClassPoolUpdater;
  import org.eclipse.steady.java.monitor.ClassVisitor;
  import org.eclipse.steady.shared.util.FileUtil;
  
  import javassist.ClassPool;
  import javassist.CtClass;
  
  /**
   * Analyzes class files.
   */
  public class ClassFileAnalyzer implements FileAnalyzer {
  
    private static final Logger log =
        org.apache.logging.log4j.LogManager.getLogger(ClassFileAnalyzer.class);
  
    /** The file to be analyzed. */
    private File file = null;
  
    /** All Java constructs found in the given class file. */
    private Map<ConstructId, Construct> constructs = null;
  
    /** {@inheritDoc} */
    @Override
    public String[] getSupportedFileExtensions() {
      return new String[] {"class"};
    }
  
    /** {@inheritDoc} */
    @Override
    public boolean canAnalyze(File _file) {
      final String ext = FileUtil.getFileExtension(_file);
      if (ext == null || ext.equals("")) return false;
      for (String supported_ext : this.getSupportedFileExtensions()) {
        if (supported_ext.equalsIgnoreCase(ext)) return true;
      }
      return false;
    }
  
    /** {@inheritDoc} */
    @Override
    public void analyze(final File _file) throws FileAnalysisException {
      this.setFile(_file);
    }
  
    /**
     * <p>Setter for the field <code>file</code>.</p>
     *
     * @param _file a {@link java.io.File} object.
     * @throws java.lang.IllegalArgumentException if any.
     */
    public void setFile(File _file) throws IllegalArgumentException {
      final String ext = FileUtil.getFileExtension(_file);
      if (!ext.equals("class"))
        throw new IllegalArgumentException("Expected a class file but got [" + _file + "]");
      if (!FileUtil.isAccessibleFile(_file.toPath()))
        throw new IllegalArgumentException("Cannot open file [" + _file + "]");
      this.file = _file;
    }
  
    /** {@inheritDoc} */
    @Override
    public Map<ConstructId, Construct> getConstructs() throws FileAnalysisException {
      if (this.constructs == null) {
        try {
          this.constructs = new TreeMap<ConstructId, Construct>();
  
          // Create a Javassist representation of the class file
          final CtClass ctclass;
          try (final FileInputStream fis = new FileInputStream(this.file)) {
            ctclass = ClassPool.getDefault().makeClass(fis);
          }
  
          // Update default class pool so that other classes are also found (e.g., the declaring class
          // of nested classes when constructing the ClassVisitor)
          // TODO HP, 4.4.16: This does not yet seem to work
          ClassPoolUpdater.getInstance().updateClasspath(ctclass, this.file);
  
          // Only add constructs of ctclass is either a class or enum (no interfaces)
          if (ctclass.isInterface()) {
            ClassFileAnalyzer.log.debug("Interface [" + ctclass.getName() + "] skipped");
          } else {
            // Use a class visitor to get all constructs from the class file
            final ClassVisitor cv = new ClassVisitor(ctclass);
            final Set<ConstructId> temp_constructs = cv.getConstructs();
  
            // Add all constructs with a "" body
            // TODO: Change Construct so that string (for source files) and binary bodies (file
            // compiled classes) can be covered
            for (ConstructId c : temp_constructs) this.constructs.put(c, new Construct(c, ""));
          }
        } catch (FileNotFoundException e) {
          throw new FileAnalysisException(e.getMessage(), e);
        } catch (IOException e) {
          throw new FileAnalysisException(
              "IO exception while analysing class file ["
                  + this.file.getName()
                  + "]: "
                  + e.getMessage(),
              e);
        } catch (RuntimeException e) {
          throw new FileAnalysisException(
              "Runtime exception while analysing class file ["
                  + this.file.getName()
                  + "]: "
                  + e.getMessage(),
              e);
        }
      }
      return this.constructs;
    }
  
    /** {@inheritDoc} */
    @Override
    public boolean containsConstruct(ConstructId _id) throws FileAnalysisException {
      return this.getConstructs().containsKey(_id);
    }
  
    /** {@inheritDoc} */
    @Override
    public Construct getConstruct(ConstructId _id) throws FileAnalysisException {
      return this.getConstructs().get(_id);
    }
  
    /** {@inheritDoc} */
    @Override
    public boolean hasChilds() {
      return false;
    }
  
    /** {@inheritDoc} */
    @Override
    public Set<FileAnalyzer> getChilds(boolean _recursive) {
      return null;
    }
  }
  