Appendix: Encryption

EMF has the possibility to encrypt the data model before writing it and to decrypt it before loading. The following demonstrates this.

Create an model based on the following interface.

   
package mymodel;

import org.eclipse.emf.ecore.EObject;
/**
* @model
*/
public interface IPerson extends EObject {
 /**
  * @model default="";
  */
 public String getLastname();
}


  

Create the following factory which sets the option for encryption.

   
package factory;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.impl.AESCipherImpl;
import org.eclipse.emf.ecore.xmi.XMIResource;
import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;

public class MyXMIFactoryImpl extends XMIResourceFactoryImpl {

 @Override
 public Resource createResource(URI uri) {
  XMIResourceFactoryImpl resFactory = new XMIResourceFactoryImpl();
  XMIResource resource = (XMIResource) resFactory.createResource(uri);
  try {
   resource.getDefaultLoadOptions().put(Resource.OPTION_CIPHER,
     new AESCipherImpl("12345"));
   resource.getDefaultSaveOptions().put(Resource.OPTION_CIPHER,
     new AESCipherImpl("12345"));
  } catch (Exception e) {
   e.printStackTrace();
  }
  return resource;
 }
}

  

Create the following test class.

   
package load;

import java.io.IOException;
import java.util.Collections;
import java.util.Map;

import mymodel.IPerson;
import mymodel.MymodelFactory;
import mymodel.impl.MymodelPackageImpl;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;

import factory.MyXMIFactoryImpl;

public class Create {
 public void create() {
  MymodelPackageImpl.init();
  // Retrieve the default factory singleton
  MymodelFactory factory = MymodelFactory.eINSTANCE;

  // Create the content of the model via this program
  IPerson person = factory.createIPerson();
  person.setLastname("Lars");

  // Register the XMI resource factory for the .website extension
  Resource.Factory.Registry reg = Resource.Factory.Registry.INSTANCE;
  Map m = reg.getExtensionToFactoryMap();
  m.put("person", new MyXMIFactoryImpl());

  // Obtain a new resource set
  ResourceSet resSet = new ResourceSetImpl();

  // Create a resource
  Resource resource = resSet.createResource(URI
  .createURI("mymodel.person"));
  resource.getContents().add(person);

  // Now save the content.
   try {
    resource.save(Collections.EMPTY_MAP);
   } catch (IOException e) {
    e.printStackTrace();
   }
 }
 
 public void load() {
  // Initialize the model
  MymodelPackageImpl.init();
  // Register the XMI resource factory for the .website extension
  Resource.Factory.Registry reg = Resource.Factory.Registry.INSTANCE;
  Map m = reg.getExtensionToFactoryMap();
  m.put("person", new MyXMIFactoryImpl());
  ResourceSet resSet = new ResourceSetImpl();
  Resource resource = resSet.getResource(URI
    .createURI("mymodel.person"), true);
  try {
   IPerson person= (IPerson) resource.getContents().get(0);
   System.out.println(person.getLastname());
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
 
 public static void main(String[] args){
  Create test = new Create();
  test.create();
  test.load();
 }
}