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.IOException; import java.io.InputStream; import org.eclipse.core.resources.*; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.NullProgressMonitor; import org.eclipse.core.runtime.Path; 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.IJavaElementDelta; import org.eclipse.jdt.core.IJavaModelStatus; import org.eclipse.jdt.core.IJavaModelStatusConstants; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.IPackageFragment; import org.eclipse.jdt.core.JavaConventions; 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; /** * <p>This operation creates a compilation unit (CU). * If the CU doesn't exist yet, a new compilation unit will be created with the content provided. * Otherwise the operation will override the contents of an existing CU with the new content. * * <p>Note: It is possible to create a CU automatically when creating a * class or interface. Thus, the preferred method of creating a CU is * to perform a create type operation rather than * first creating a CU and secondly creating a type inside the CU. * * <p>Required Attributes:<ul> * <li>The package fragment in which to create the compilation unit. * <li>The name of the compilation unit. * Do not include the <code>".java"</code> suffix (ex. <code>"Object"</code> - * the <code>".java"</code> will be added for the name of the compilation unit.) * <li> * </ul> */ public class CreateCompilationUnitOperation extends JavaModelOperation { /** * The name of the compilation unit being created. */ protected String name; /** * The source code to use when creating the element. */ protected String source = null; /** * When executed, this operation will create a compilation unit with the given name. * The name should have the ".java" suffix. */ public CreateCompilationUnitOperation(IPackageFragment parentElement, String name, String source, boolean force) { super(null, new IJavaElement[] { parentElement }, force); this.name = name; this.source = source; } /** * Creates a compilation unit. * * @exception JavaModelException if unable to create the compilation unit. */ @Override protected void executeOperation() throws JavaModelException { try { beginTask(Messages.operation_createUnitProgress, 2); JavaElementDelta delta = newJavaElementDelta(); ICompilationUnit unit = getCompilationUnit(); IPackageFragment pkg = (IPackageFragment) getParentElement(); IContainer folder = (IContainer) pkg.getResource(); worked(1); IFile compilationUnitFile = folder.getFile(new Path(this.name)); if (compilationUnitFile.exists()) { // update the contents of the existing unit if fForce is true if (this.force) { IBuffer buffer = unit.getBuffer(); if (buffer == null) return; buffer.setContents(this.source); unit.save(new NullProgressMonitor(), false); this.resultElements = new IJavaElement[] { unit }; if (!Util.isExcluded(unit) && unit.getParent().exists()) { for (int i = 0; i < this.resultElements.length; i++) { delta.changed(this.resultElements[i], IJavaElementDelta.F_CONTENT); } addDelta(delta); } } else { throw new JavaModelException( new JavaModelStatus(IJavaModelStatusConstants.NAME_COLLISION, Messages.bind( Messages.status_nameCollision, compilationUnitFile.getFullPath().toString()))); } } else { try { String encoding = null; try { encoding = folder.getDefaultCharset(); // get folder encoding as file is not accessible } catch (CoreException ce) { // use no encoding } InputStream stream = new ByteArrayInputStream( encoding == null ? this.source.getBytes() : this.source.getBytes(encoding)); createFile(folder, unit.getElementName(), stream, this.force); this.resultElements = new IJavaElement[] { unit }; if (!Util.isExcluded(unit) && unit.getParent().exists()) { for (int i = 0; i < this.resultElements.length; i++) { delta.added(this.resultElements[i]); } addDelta(delta); } } catch (IOException e) { throw new JavaModelException(e, IJavaModelStatusConstants.IO_EXCEPTION); } } worked(1); } finally { done(); } } /** * @see CreateElementInCUOperation#getCompilationUnit() */ protected ICompilationUnit getCompilationUnit() { return ((IPackageFragment) getParentElement()).getCompilationUnit(this.name); } @Override protected ISchedulingRule getSchedulingRule() { IResource resource = getCompilationUnit().getResource(); IWorkspace workspace = resource.getWorkspace(); if (resource.exists()) { return workspace.getRuleFactory().modifyRule(resource); } else { return workspace.getRuleFactory().createRule(resource); } } /** * Possible failures: <ul> * <li>NO_ELEMENTS_TO_PROCESS - the package fragment supplied to the operation is * <code>null</code>. * <li>INVALID_NAME - the compilation unit name provided to the operation * is <code>null</code> or has an invalid syntax * <li>INVALID_CONTENTS - the source specified for the compiliation unit is null * </ul> */ @Override public IJavaModelStatus verify() { if (getParentElement() == null) { return new JavaModelStatus(IJavaModelStatusConstants.NO_ELEMENTS_TO_PROCESS); } IJavaProject project = getParentElement().getJavaProject(); if (JavaConventions .validateCompilationUnitName(this.name, project.getOption(JavaCore.COMPILER_SOURCE, true), project.getOption(JavaCore.COMPILER_COMPLIANCE, true)) .getSeverity() == IStatus.ERROR) { return new JavaModelStatus(IJavaModelStatusConstants.INVALID_NAME, this.name); } if (this.source == null) { return new JavaModelStatus(IJavaModelStatusConstants.INVALID_CONTENTS); } return JavaModelStatus.VERIFIED_OK; } }