Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2009 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.internal.core; import java.io.ByteArrayInputStream; import java.io.UnsupportedEncodingException; import org.eclipse.core.resources.IFile; import org.eclipse.core.resources.IResource; import org.eclipse.core.resources.IWorkspace; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.jobs.ISchedulingRule; import org.eclipse.jdt.core.IBuffer; import org.eclipse.jdt.core.ICompilationUnit; import org.eclipse.jdt.core.IJavaElement; import org.eclipse.jdt.core.IJavaModelStatus; import org.eclipse.jdt.core.IJavaModelStatusConstants; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.JavaCore; import org.eclipse.jdt.core.JavaModelException; import org.eclipse.jdt.internal.core.util.Messages; import org.eclipse.jdt.internal.core.util.Util; /** * Commits the contents of a working copy compilation * unit to its original element and resource, bringing * the Java Model up-to-date with the current contents of the working * copy. * * <p>It is possible that the contents of the * original resource have changed since the working copy was created, * in which case there is an update conflict. This operation allows * for two settings to resolve conflict set by the <code>fForce</code> flag:<ul> * <li>force flag is <code>false</code> - in this case an <code>JavaModelException</code> * is thrown</li> * <li>force flag is <code>true</code> - in this case the contents of * the working copy are applied to the underlying resource even though * the working copy was created before a subsequent change in the * resource</li> * </ul> * * <p>The default conflict resolution setting is the force flag is <code>false</code> * * A JavaModelOperation exception is thrown either if the commit could not * be performed or if the new content of the compilation unit violates some Java Model * constraint (e.g. if the new package declaration doesn't match the name of the folder * containing the compilation unit). */ public class CommitWorkingCopyOperation extends JavaModelOperation { /** * Constructs an operation to commit the contents of a working copy * to its original compilation unit. */ public CommitWorkingCopyOperation(ICompilationUnit element, boolean force) { super(new IJavaElement[] { element }, force); } /** * @exception JavaModelException if setting the source * of the original compilation unit fails */ @Override protected void executeOperation() throws JavaModelException { try { beginTask(Messages.workingCopy_commit, 2); CompilationUnit workingCopy = getCompilationUnit(); if (ExternalJavaProject.EXTERNAL_PROJECT_NAME.equals(workingCopy.getJavaProject().getElementName())) { // case of a working copy without a resource workingCopy.getBuffer().save(this.progressMonitor, this.force); return; } ICompilationUnit primary = workingCopy.getPrimary(); boolean isPrimary = workingCopy.isPrimary(); JavaElementDeltaBuilder deltaBuilder = null; PackageFragmentRoot root = (PackageFragmentRoot) workingCopy .getAncestor(IJavaElement.PACKAGE_FRAGMENT_ROOT); boolean isIncluded = !Util.isExcluded(workingCopy); IFile resource = (IFile) workingCopy.getResource(); IJavaProject project = root.getJavaProject(); if (isPrimary || (root.validateOnClasspath().isOK() && isIncluded && resource.isAccessible() && Util.isValidCompilationUnitName(workingCopy.getElementName(), project.getOption(JavaCore.COMPILER_SOURCE, true), project.getOption(JavaCore.COMPILER_COMPLIANCE, true)))) { // force opening so that the delta builder can get the old info if (!isPrimary && !primary.isOpen()) { primary.open(null); } // creates the delta builder (this remembers the content of the cu) if: // - it is not excluded // - and it is not a primary or it is a non-consistent primary if (isIncluded && (!isPrimary || !workingCopy.isConsistent())) { deltaBuilder = new JavaElementDeltaBuilder(primary); } // save the cu IBuffer primaryBuffer = primary.getBuffer(); if (!isPrimary) { if (primaryBuffer == null) return; char[] primaryContents = primaryBuffer.getCharacters(); boolean hasSaved = false; try { IBuffer workingCopyBuffer = workingCopy.getBuffer(); if (workingCopyBuffer == null) return; primaryBuffer.setContents(workingCopyBuffer.getCharacters()); primaryBuffer.save(this.progressMonitor, this.force); primary.makeConsistent(this); hasSaved = true; } finally { if (!hasSaved) { // restore original buffer contents since something went wrong primaryBuffer.setContents(primaryContents); } } } else { // for a primary working copy no need to set the content of the buffer again primaryBuffer.save(this.progressMonitor, this.force); primary.makeConsistent(this); } } else { // working copy on cu outside classpath OR resource doesn't exist yet String encoding = null; try { encoding = resource.getCharset(); } catch (CoreException ce) { // use no encoding } String contents = workingCopy.getSource(); if (contents == null) return; try { byte[] bytes = encoding == null ? contents.getBytes() : contents.getBytes(encoding); ByteArrayInputStream stream = new ByteArrayInputStream(bytes); if (resource.exists()) { resource.setContents(stream, this.force ? IResource.FORCE | IResource.KEEP_HISTORY : IResource.KEEP_HISTORY, null); } else { resource.create(stream, this.force, this.progressMonitor); } } catch (CoreException e) { throw new JavaModelException(e); } catch (UnsupportedEncodingException e) { throw new JavaModelException(e, IJavaModelStatusConstants.IO_EXCEPTION); } } setAttribute(HAS_MODIFIED_RESOURCE_ATTR, TRUE); // make sure working copy is in sync workingCopy.updateTimeStamp((CompilationUnit) primary); workingCopy.makeConsistent(this); worked(1); // build the deltas if (deltaBuilder != null) { deltaBuilder.buildDeltas(); // add the deltas to the list of deltas created during this operation if (deltaBuilder.delta != null) { addDelta(deltaBuilder.delta); } } worked(1); } finally { done(); } } /** * Returns the compilation unit this operation is working on. */ protected CompilationUnit getCompilationUnit() { return (CompilationUnit) getElementToProcess(); } @Override protected ISchedulingRule getSchedulingRule() { IResource resource = getElementToProcess().getResource(); if (resource == null) return null; IWorkspace workspace = resource.getWorkspace(); if (resource.exists()) { return workspace.getRuleFactory().modifyRule(resource); } else { return workspace.getRuleFactory().createRule(resource); } } /** * Possible failures: <ul> * <li>INVALID_ELEMENT_TYPES - the compilation unit supplied to this * operation is not a working copy * <li>ELEMENT_NOT_PRESENT - the compilation unit the working copy is * based on no longer exists. * <li>UPDATE_CONFLICT - the original compilation unit has changed since * the working copy was created and the operation specifies no force * <li>READ_ONLY - the original compilation unit is in read-only mode * </ul> */ @Override public IJavaModelStatus verify() { CompilationUnit cu = getCompilationUnit(); if (!cu.isWorkingCopy()) { return new JavaModelStatus(IJavaModelStatusConstants.INVALID_ELEMENT_TYPES, cu); } if (cu.hasResourceChanged() && !this.force) { return new JavaModelStatus(IJavaModelStatusConstants.UPDATE_CONFLICT); } // no read-only check, since some repository adapters can change the flag on save // operation. return JavaModelStatus.VERIFIED_OK; } }