distributedevent.java

Java 3D Desktop Environment旨在使用Java 3D来创建一个3D桌面环境。功能包括：分布式的应用程序

package org.j3de.events;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.io.StreamCorruptedException;
import java.security.PublicKey;
import java.security.PrivateKey;
import java.security.Signature;
import java.security.SignatureException;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;

import org.j3de.security.SecurityFactory;
import org.j3de.exception.ExceptionHandler;

public final class DistributedEvent implements Serializable {
  private PublicKey receiver;
  private PublicKey sender;
  private byte[] encodedEvent;
  private byte[] signed;
  private String classname;

  public DistributedEvent(PublicKey receiver,
                          Class receiverApp,
                          Serializable event,
                          SecurityFactory securityFactory) throws DistributedEventCreationException {
    this.receiver = receiver;
    this.sender   = securityFactory.getPublicKey();

    try {
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      ObjectOutputStream out =
        new ObjectOutputStream(
          new CipherOutputStream(baos, securityFactory.getEncodingCipher()));
      out.writeObject(event);
      out.close();

      Signature signature = securityFactory.getSignature();
      signature.update(encodedEvent);

      this.encodedEvent = baos.toByteArray();
      this.signed       = signature.sign();
      this.classname    = receiverApp.getName();
    } catch (IOException e) {
      throw new DistributedEventCreationException(e);
    } catch (SignatureException e2) {
      throw new DistributedEventCreationException(e2);
    }

  }

  public PublicKey getReceiver() {
    return receiver;
  }

  public PublicKey getSender() {
    return sender;
  }

  public Object getEvent(SecurityFactory securityFactory)
    throws DistributedEventCorruptedException, UnknownEventException {
    try {
      ByteArrayInputStream baos = new ByteArrayInputStream(encodedEvent);
      ObjectInputStream in =
        new ObjectInputStream(
          new CipherInputStream(baos, securityFactory.getDecodingCipher()));

      Object obj = in.readObject();

      in.close();

      return obj;
    } catch (StreamCorruptedException e) {
      throw new DistributedEventCorruptedException(e);
    } catch (IOException e2) {
      throw new DistributedEventCorruptedException(e2);
    } catch (ClassNotFoundException e3) {
      throw new UnknownEventException(e3.getMessage());
    }
  }

  public boolean verify(SecurityFactory securityFactory) {
    try {
      Signature signature = securityFactory.getVerifySignature(sender);
      signature.update(encodedEvent);
      return signature.verify(signed);
    } catch (SignatureException e) {
      ExceptionHandler.handleException(e);
      return false;
    }
  }

}