org.eclipse.blockchain.core/src/org/eclipse/blockchain/classloader/DynamicClassLoader.java

/*
 * Copyright (c) Robert Bosch GmbH. All rights reserved.
 */
package org.eclipse.blockchain.classloader;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import org.eclipse.blockchain.core.BlockchainCore;
import org.eclipse.blockchain.core.ProjectCreator;
import org.eclipse.core.resources.IResource;

/**
 * @author ADG5COB
 */
public class DynamicClassLoader extends ClassLoader {

  String directoryLocation = "";
  String projectName = "";

  /**
   * @param parentLoader -
   * @param projectName -
   * @param directory -
   */
  public DynamicClassLoader(final ClassLoader parentLoader, final String projectName, final String directory) {
    super(parentLoader);
    this.directoryLocation = directory;
    this.projectName = projectName;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public Class<?> loadClass(final String name) throws ClassNotFoundException {
    if (shouldBeHandled(name)) {
      URL url;
      try {
        url = new URL("file:" + this.directoryLocation + File.separator + name.replace(".", File.separator) + ".class");
        URLConnection urlConn = url.openConnection();
        InputStream is = urlConn.getInputStream();
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        int data = is.read();

        while (data != -1) {
          buffer.write(data);
          data = is.read();
        }
        is.close();

        byte[] classData = buffer.toByteArray();

        return defineClass(name, classData, 0, classData.length);
      }
      catch (Exception e) {
        BlockchainCore.getInstance().logException("", e.getMessage(), e);
      }
    }
    return super.loadClass(name);
  }

  private boolean shouldBeHandled(final String name) {
    if (getSmartContracts().contains(name.substring(name.lastIndexOf('.') + 1))) {
      return true;
    }
    else if (name.contains("$") &&
        getSmartContracts().contains(name.substring(name.lastIndexOf('.') + 1, name.indexOf('$')))) {
      return true;
    }
    else if (name.equals("org.eclipse.blockchain.core.SolidityDynamicValueCaster")) {
      return true;
    }
    else if (name.equals("org.eclipse.blockchain.core.SolidityDatatypeToJavaDatatype")) {
      return true;
    }
    return false;
  }

  private List<String> getSmartContracts() {
    Set<IResource> solFiles = ProjectCreator.getInstance().getEthProject(this.projectName).getCompiledSolidityFiles();
    return solFiles.stream().map(IResource::getName).map(r -> r.replace(".sol", "")).collect(Collectors.toList());
  }
}