doc/org.eclipse.emf.examples.jet.article2/src/org/eclipse/emf/examples/jet/article2/codegen/JETGateway.java - emf/org.eclipse.emf - Git at Google

 package org.eclipse.emf.examples.jet.article2.codegen;


 import java.io.ByteArrayInputStream;
 import java.io.InputStream;

 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.ResourceAttributes;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.Status;

 import org.eclipse.emf.codegen.jet.JETEmitter;
 import org.eclipse.emf.codegen.jet.JETException;
 import org.eclipse.emf.codegen.merge.java.JControlModel;
 import org.eclipse.emf.codegen.merge.java.JMerger;
 import org.eclipse.emf.codegen.util.CodeGenUtil;
 import org.eclipse.emf.common.util.BasicMonitor;
 import org.eclipse.emf.common.util.DiagnosticException;
 import org.eclipse.emf.common.util.Monitor;


 /**
  * This class encapsulates access to the JET and JMerge packages.
  *
  * @author Remko Popma
  * @version $Revision: 1.5 $ ($Date: 2006/12/29 21:12:36 $)
  */
 public class JETGateway
 {

   private Config mConfig = null;

   public JETGateway(Config config)
   {
     mConfig = config;
   }

   /**
    * Invokes the JET template specified in the <code>Config</code> with the
    * model specified in the <code>Config</code> and returns the generated text
    * as a String.
    * <p>
    * This implementation uses a <code>JETEmitter</code> to translate the
    * template to a Java implementation class. The translated class is created in
    * a hidden project called <code>.JETEmitters</code>.
    * <p>
    * In order to be able to compile the translated template implementation
    * class, the classes used by the model specified in the <code>Config</code>
    * must be available in the classpath. For this reason, this method sets the
    * first runtime library of the plugin specified in the <code>Config</code>
    * as a classpath variable to the <code>.JETEmitters</code> project.
    *
    * @param monitor
    *          the progress monitor to use. May be <code>null</code>.
    * @return the source code text generated by the JET template
    * @throws CoreException
    */
   public String generate(IProgressMonitor monitor) throws CoreException
   {
     try
     {
       monitor = createIfNull(monitor);
       Config config = getConfig();
       JETEmitter emitter = new JETEmitter(config.getTemplateFullUri(), getClass().getClassLoader());
       emitter.addVariable(config.getClasspathVariable(), config.getPluginId());

       Monitor sub = new BasicMonitor.EclipseSubProgress(monitor, 1);
       String result = emitter.generate(sub, new Object []{ config.getModel() });
       monitor.worked(1);
       return result;
     }
     catch (JETException exception)
     {
       throw DiagnosticException.toCoreException(exception);
     }
   }

   /**
    * Merges the specified emitterResult with the contents of an existing file
    * and returns the result. The existing file is not modified.
    * <p>
    * The location of the file to merge with is found by finding or creating the
    * container (folder) for the <code>Config</code>'s package in the
    * <code>Config</code>'s target folder. The name of the file to merge with
    * is the <code>Config</code>'s target file.
    *
    * @param monitor
    *          the progress monitor to use. May be <code>null</code>.
    * @param emitterResult
    *          generated content to merge with the existing content
    * @return the result of merging the specified generated contents with the
    *         existing file
    * @throws CoreException
    *           if an error occurs accessing the contents of the file
    */
   public String merge(IProgressMonitor monitor, String emitterResult) throws CoreException
   {
     monitor = createIfNull(monitor);

     Config config = getConfig();
     IContainer container = findOrCreateContainer(monitor, config.getTargetFolder(), config.getPackageName());
     if (container == null)
     {
       throw
         new CoreException
           (new Status
              (IStatus.ERROR,
               "org.eclipse.emf.examples.jet.article2",
               0,
               "Could not find or create container for package " + config.getPackageName() + " in " + config.getTargetFolder(),
               null));
     }

     IFile targetFile = container.getFile(new Path(config.getTargetFile()));
     if (!targetFile.exists())
     {
       monitor.worked(1);
       return emitterResult;
     }

     JControlModel jControlModel = new JControlModel();
     jControlModel.initialize(CodeGenUtil.instantiateFacadeHelper(JMerger.DEFAULT_FACADE_HELPER_CLASS), config.getMergeXmlFullUri());
     JMerger jMerger = new JMerger(jControlModel);
     jMerger.setSourceCompilationUnit(jMerger.createCompilationUnitForContents(emitterResult));

     jMerger.setTargetCompilationUnit(jMerger.createCompilationUnitForInputStream(targetFile.getContents(true)));
     String oldContents = jControlModel.getFacadeHelper().getOriginalContents(jMerger.getTargetCompilationUnit());

     jMerger.merge();
     monitor.worked(1);

     String result = jMerger.getTargetCompilationUnitContents();
     if (oldContents.equals(result))
     {
       return result;
     }

     if (!targetFile.isReadOnly())
     {
       return result;
     }

     // The file may be read-only because it is checked out
     // by a VCM component. Here we ask permission to change the file.
     if (targetFile.getWorkspace().validateEdit(new IFile []{ targetFile }, BasicMonitor.subProgress(monitor, 1)).isOK())
     {

       jMerger.setTargetCompilationUnit(jMerger.createCompilationUnitForInputStream(targetFile.getContents(true)));
       jMerger.remerge();
       return jMerger.getTargetCompilationUnitContents();
     }
     return result;
   }

   /**
    * Saves the specified contents to a location specified by the
    * <code>Config</code> settings. The location of the file to save is found
    * by finding or creating the container (folder) for the <code>Config</code>
    * 's package in the <code>Config</code>'s target folder. The name of the
    * file to save is the <code>Config</code>'s target file.
    *
    * @param monitor
    *          the progress monitor to use. May be <code>null</code>.
    * @param contents
    *          the byte contents of the file to save
    * @throws CoreException
    */
   public IFile save(IProgressMonitor monitor, byte[] contents) throws CoreException
   {
     monitor = createIfNull(monitor);

     Config config = getConfig();
     IContainer container = findOrCreateContainer(monitor, config.getTargetFolder(), config.getPackageName());
     if (container == null)
     {
       throw
         new CoreException
           (new Status
              (IStatus.ERROR,
               "org.eclipse.emf.examples.jet.article2",
               0,
               "Could not find or create container for package " + config.getPackageName() + " in " + config.getTargetFolder(),
               null));
     }
     IFile targetFile = container.getFile(new Path(config.getTargetFile()));
     IFile result = getWritableTargetFile(targetFile, container, config.getTargetFile());

     InputStream newContents = new ByteArrayInputStream(contents);
     if (result.exists())
     {
       result.setContents(newContents, true, true, BasicMonitor.subProgress(monitor, 1));
     }
     else
     {
       result.create(newContents, true, BasicMonitor.subProgress(monitor, 1));
     }
     return result;
   }

   /**
    * Returns a non-null progress monitor.
    *
    * @param monitor
    *          an existing progress monitor
    * @return a new <code>NullProgressMonitor</code> if the specified monitor
    *         is <code>null</code>, or the existing monitor otherwise
    */
   private IProgressMonitor createIfNull(IProgressMonitor monitor)
   {
     if (monitor == null)
     {
       return new NullProgressMonitor();
     }
     return monitor;
   }

   private IContainer findOrCreateContainer(IProgressMonitor progressMonitor, String targetDirectory, String packageName) throws CoreException
   {

     IPath outputPath = new Path(targetDirectory + "/" + packageName.replace('.', '/'));
     progressMonitor.beginTask("", 4);

     IProgressMonitor sub = BasicMonitor.subProgress(progressMonitor, 1);
     IPath localLocation = null; // use default
     IContainer container = CodeGenUtil.EclipseUtil.findOrCreateContainer(outputPath, true, localLocation, sub);
     return container;
   }

   /**
    * Returns a <code>IFile</code> that can be written to. If the specified
    * file is read-write, it is returned unchanged. If the specified file is
    * read-only and {@link Config#isForceOverwrite()}returns <code>true</code>,
    * the file is made writable, otherwise a new file is returned in the
    * specified container with filename <code>"." + fileName + ".new"</code>.
    *
    * @param container
    *          container to create the new file in if the specified file cannot
    *          be made writable
    * @param targetFile
    *          the file to make writable
    * @param fileName
    *          used to create a new file name if the specified file cannot be
    *          made writable
    * @return a <code>IFile</code> that can be written to
    */
   private IFile getWritableTargetFile(IFile targetFile, IContainer container, String fileName)
   {
     if (targetFile.isReadOnly())
     {
       if (getConfig().isForceOverwrite())
       {
         ResourceAttributes attributes = targetFile.getResourceAttributes();
         attributes.setReadOnly(false);
         try
         {
           targetFile.setResourceAttributes(attributes);
         }
         catch (CoreException e)
         {
           // Ignore
         }
       }
       else
       {
         targetFile = container.getFile(new Path("." + fileName + ".new"));
       }
     }
     return targetFile;
   }

   /**
    * Returns the <code>Config</code> object
    *
    * @return the <code>Config</code> object
    */
   protected Config getConfig()
   {
     return mConfig;
   }
 }
	package org.eclipse.emf.examples.jet.article2.codegen;


	import java.io.ByteArrayInputStream;
	import java.io.InputStream;

	import org.eclipse.core.resources.IContainer;
	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.ResourceAttributes;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.Status;

	import org.eclipse.emf.codegen.jet.JETEmitter;
	import org.eclipse.emf.codegen.jet.JETException;
	import org.eclipse.emf.codegen.merge.java.JControlModel;
	import org.eclipse.emf.codegen.merge.java.JMerger;
	import org.eclipse.emf.codegen.util.CodeGenUtil;
	import org.eclipse.emf.common.util.BasicMonitor;
	import org.eclipse.emf.common.util.DiagnosticException;
	import org.eclipse.emf.common.util.Monitor;


	/**
	* This class encapsulates access to the JET and JMerge packages.
	*
	* @author Remko Popma
	* @version $Revision: 1.5 $ ($Date: 2006/12/29 21:12:36 $)
	*/
	public class JETGateway
	{

	private Config mConfig = null;

	public JETGateway(Config config)
	{
	mConfig = config;
	}

	/**
	* Invokes the JET template specified in the <code>Config</code> with the
	* model specified in the <code>Config</code> and returns the generated text
	* as a String.
	* <p>
	* This implementation uses a <code>JETEmitter</code> to translate the
	* template to a Java implementation class. The translated class is created in
	* a hidden project called <code>.JETEmitters</code>.
	* <p>
	* In order to be able to compile the translated template implementation
	* class, the classes used by the model specified in the <code>Config</code>
	* must be available in the classpath. For this reason, this method sets the
	* first runtime library of the plugin specified in the <code>Config</code>
	* as a classpath variable to the <code>.JETEmitters</code> project.
	*
	* @param monitor
	* the progress monitor to use. May be <code>null</code>.
	* @return the source code text generated by the JET template
	* @throws CoreException
	*/
	public String generate(IProgressMonitor monitor) throws CoreException
	{
	try
	{
	monitor = createIfNull(monitor);
	Config config = getConfig();
	JETEmitter emitter = new JETEmitter(config.getTemplateFullUri(), getClass().getClassLoader());
	emitter.addVariable(config.getClasspathVariable(), config.getPluginId());

	Monitor sub = new BasicMonitor.EclipseSubProgress(monitor, 1);
	String result = emitter.generate(sub, new Object []{ config.getModel() });
	monitor.worked(1);
	return result;
	}
	catch (JETException exception)
	{
	throw DiagnosticException.toCoreException(exception);
	}
	}

	/**
	* Merges the specified emitterResult with the contents of an existing file
	* and returns the result. The existing file is not modified.
	* <p>
	* The location of the file to merge with is found by finding or creating the
	* container (folder) for the <code>Config</code>'s package in the
	* <code>Config</code>'s target folder. The name of the file to merge with
	* is the <code>Config</code>'s target file.
	*
	* @param monitor
	* the progress monitor to use. May be <code>null</code>.
	* @param emitterResult
	* generated content to merge with the existing content
	* @return the result of merging the specified generated contents with the
	* existing file
	* @throws CoreException
	* if an error occurs accessing the contents of the file
	*/
	public String merge(IProgressMonitor monitor, String emitterResult) throws CoreException
	{
	monitor = createIfNull(monitor);

	Config config = getConfig();
	IContainer container = findOrCreateContainer(monitor, config.getTargetFolder(), config.getPackageName());
	if (container == null)
	{
	throw
	new CoreException
	(new Status
	(IStatus.ERROR,
	"org.eclipse.emf.examples.jet.article2",
	0,
	"Could not find or create container for package " + config.getPackageName() + " in " + config.getTargetFolder(),
	null));
	}

	IFile targetFile = container.getFile(new Path(config.getTargetFile()));
	if (!targetFile.exists())
	{
	monitor.worked(1);
	return emitterResult;
	}

	JControlModel jControlModel = new JControlModel();
	jControlModel.initialize(CodeGenUtil.instantiateFacadeHelper(JMerger.DEFAULT_FACADE_HELPER_CLASS), config.getMergeXmlFullUri());
	JMerger jMerger = new JMerger(jControlModel);
	jMerger.setSourceCompilationUnit(jMerger.createCompilationUnitForContents(emitterResult));

	jMerger.setTargetCompilationUnit(jMerger.createCompilationUnitForInputStream(targetFile.getContents(true)));
	String oldContents = jControlModel.getFacadeHelper().getOriginalContents(jMerger.getTargetCompilationUnit());

	jMerger.merge();
	monitor.worked(1);

	String result = jMerger.getTargetCompilationUnitContents();
	if (oldContents.equals(result))
	{
	return result;
	}

	if (!targetFile.isReadOnly())
	{
	return result;
	}

	// The file may be read-only because it is checked out
	// by a VCM component. Here we ask permission to change the file.
	if (targetFile.getWorkspace().validateEdit(new IFile []{ targetFile }, BasicMonitor.subProgress(monitor, 1)).isOK())
	{

	jMerger.setTargetCompilationUnit(jMerger.createCompilationUnitForInputStream(targetFile.getContents(true)));
	jMerger.remerge();
	return jMerger.getTargetCompilationUnitContents();
	}
	return result;
	}

	/**
	* Saves the specified contents to a location specified by the
	* <code>Config</code> settings. The location of the file to save is found
	* by finding or creating the container (folder) for the <code>Config</code>
	* 's package in the <code>Config</code>'s target folder. The name of the
	* file to save is the <code>Config</code>'s target file.
	*
	* @param monitor
	* the progress monitor to use. May be <code>null</code>.
	* @param contents
	* the byte contents of the file to save
	* @throws CoreException
	*/
	public IFile save(IProgressMonitor monitor, byte[] contents) throws CoreException
	{
	monitor = createIfNull(monitor);

	Config config = getConfig();
	IContainer container = findOrCreateContainer(monitor, config.getTargetFolder(), config.getPackageName());
	if (container == null)
	{
	throw
	new CoreException
	(new Status
	(IStatus.ERROR,
	"org.eclipse.emf.examples.jet.article2",
	0,
	"Could not find or create container for package " + config.getPackageName() + " in " + config.getTargetFolder(),
	null));
	}
	IFile targetFile = container.getFile(new Path(config.getTargetFile()));
	IFile result = getWritableTargetFile(targetFile, container, config.getTargetFile());

	InputStream newContents = new ByteArrayInputStream(contents);
	if (result.exists())
	{
	result.setContents(newContents, true, true, BasicMonitor.subProgress(monitor, 1));
	}
	else
	{
	result.create(newContents, true, BasicMonitor.subProgress(monitor, 1));
	}
	return result;
	}

	/**
	* Returns a non-null progress monitor.
	*
	* @param monitor
	* an existing progress monitor
	* @return a new <code>NullProgressMonitor</code> if the specified monitor
	* is <code>null</code>, or the existing monitor otherwise
	*/
	private IProgressMonitor createIfNull(IProgressMonitor monitor)
	{
	if (monitor == null)
	{
	return new NullProgressMonitor();
	}
	return monitor;
	}

	private IContainer findOrCreateContainer(IProgressMonitor progressMonitor, String targetDirectory, String packageName) throws CoreException
	{

	IPath outputPath = new Path(targetDirectory + "/" + packageName.replace('.', '/'));
	progressMonitor.beginTask("", 4);

	IProgressMonitor sub = BasicMonitor.subProgress(progressMonitor, 1);
	IPath localLocation = null; // use default
	IContainer container = CodeGenUtil.EclipseUtil.findOrCreateContainer(outputPath, true, localLocation, sub);
	return container;
	}

	/**
	* Returns a <code>IFile</code> that can be written to. If the specified
	* file is read-write, it is returned unchanged. If the specified file is
	* read-only and {@link Config#isForceOverwrite()}returns <code>true</code>,
	* the file is made writable, otherwise a new file is returned in the
	* specified container with filename <code>"." + fileName + ".new"</code>.
	*
	* @param container
	* container to create the new file in if the specified file cannot
	* be made writable
	* @param targetFile
	* the file to make writable
	* @param fileName
	* used to create a new file name if the specified file cannot be
	* made writable
	* @return a <code>IFile</code> that can be written to
	*/
	private IFile getWritableTargetFile(IFile targetFile, IContainer container, String fileName)
	{
	if (targetFile.isReadOnly())
	{
	if (getConfig().isForceOverwrite())
	{
	ResourceAttributes attributes = targetFile.getResourceAttributes();
	attributes.setReadOnly(false);
	try
	{
	targetFile.setResourceAttributes(attributes);
	}
	catch (CoreException e)
	{
	// Ignore
	}
	}
	else
	{
	targetFile = container.getFile(new Path("." + fileName + ".new"));
	}
	}
	return targetFile;
	}

	/**
	* Returns the <code>Config</code> object
	*
	* @return the <code>Config</code> object
	*/
	protected Config getConfig()
	{
	return mConfig;
	}
	}