org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/util/InfoFilesUtil.java

/*******************************************************************************
 * Copyright (c) 2016 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * This is an implementation of an early-draft specification developed under the Java
 * Community Process (JCP) and is made available for testing and evaluation purposes
 * only. The code is not compatible with any specification of the JCP.
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.util;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.SubProgressMonitor;

import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.ISourceRange;
import org.eclipse.jdt.core.formatter.CodeFormatter;

import org.eclipse.jdt.internal.corext.codemanipulation.StubUtility;

import org.eclipse.jdt.ui.CodeGeneration;

public class InfoFilesUtil {

	/**
	 * Creates a compilation unit in the given package fragment with the specified file name. The
	 * compilation unit is formatted and contains the given contents with file and type comments
	 * prepended to it.
	 * 
	 * @param fileName the name of the compilation unit
	 * @param fileContent the contents of the compilation unit
	 * @param pack the package fragment to create the compilation unit in
	 * @param monitor the progress monitor
	 * @throws CoreException when there is a problem while creating the compilation unit
	 */
	public static void createInfoJavaFile(String fileName, String fileContent, IPackageFragment pack, IProgressMonitor monitor) throws CoreException {
		String lineDelimiter= StubUtility.getLineDelimiterUsed(pack.getJavaProject());
		StringBuilder content= new StringBuilder();
		String fileComment= getFileComment(fileName, pack, lineDelimiter);
		String typeComment= getTypeComment(fileName, pack, lineDelimiter);

		if (fileComment != null) {
			content.append(fileComment);
			content.append(lineDelimiter);
		}

		if (typeComment != null) {
			content.append(typeComment);
			content.append(lineDelimiter);
		} else if (fileComment != null) {
			// insert an empty file comment to avoid that the file comment becomes the type comment
			content.append("/**"); //$NON-NLS-1$
			content.append(lineDelimiter);
			content.append(" *"); //$NON-NLS-1$
			content.append(lineDelimiter);
			content.append(" */"); //$NON-NLS-1$
			content.append(lineDelimiter);
		}

		content.append(fileContent);

		ICompilationUnit compilationUnit= pack.createCompilationUnit(fileName, content.toString(), true, monitor);

		JavaModelUtil.reconcile(compilationUnit);

		compilationUnit.becomeWorkingCopy(monitor);
		try {
			IBuffer buffer= compilationUnit.getBuffer();
			ISourceRange sourceRange= compilationUnit.getSourceRange();
			String originalContent= buffer.getText(sourceRange.getOffset(), sourceRange.getLength());

			String formattedContent= CodeFormatterUtil.format(CodeFormatter.K_COMPILATION_UNIT, originalContent, 0, lineDelimiter, pack.getJavaProject());
			formattedContent= Strings.trimLeadingTabsAndSpaces(formattedContent);
			buffer.replace(sourceRange.getOffset(), sourceRange.getLength(), formattedContent);
			compilationUnit.commitWorkingCopy(true, new SubProgressMonitor(monitor, 1));
		} finally {
			compilationUnit.discardWorkingCopy();
		}
	}

	public static String getFileComment(String fileName, IPackageFragment pack, String lineDelimiterUsed) throws CoreException {
		ICompilationUnit cu= pack.getCompilationUnit(fileName);
		return CodeGeneration.getFileComment(cu, lineDelimiterUsed);
	}

	public static String getTypeComment(String fileName, IPackageFragment pack, String lineDelimiterUsed) throws CoreException {
		ICompilationUnit cu= pack.getCompilationUnit(fileName);
		String typeName= fileName.substring(0, fileName.length() - JavaModelUtil.DEFAULT_CU_SUFFIX.length());
		return CodeGeneration.getTypeComment(cu, typeName, lineDelimiterUsed);
	}

}