Java tutorial
/******************************************************************************* * MontiCore Language Workbench * Copyright (c) 2015, 2016, MontiCore, All rights reserved. * * This project is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3.0 of the License, or (at your option) any later version. * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this project. If not, see <http://www.gnu.org/licenses/>. *******************************************************************************/ package de.se_rwth.langeditor.util; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.InvocationTargetException; import java.net.URL; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.HashSet; import java.util.List; import java.util.Optional; import java.util.Set; import java.util.Stack; import java.util.function.Consumer; import java.util.function.Function; import java.util.function.Predicate; import java.util.stream.Collectors; import java.util.stream.Stream; import org.apache.commons.io.IOUtils; import org.eclipse.core.resources.IFile; import org.eclipse.core.resources.IProject; import org.eclipse.core.resources.IStorage; import org.eclipse.core.runtime.CoreException; import org.eclipse.jdt.core.IClasspathEntry; import org.eclipse.jdt.core.IJarEntryResource; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.JavaModelException; import org.eclipse.jdt.internal.ui.javaeditor.JarEntryEditorInput; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Display; import org.eclipse.ui.IEditorInput; import org.eclipse.ui.IStorageEditorInput; import org.eclipse.ui.part.FileEditorInput; @SuppressWarnings("restriction") public final class Misc { private Misc() { // noninstantiable } public static Optional<Image> loadImage(String location) { try { URL url = new URL("platform:/plugin/texteditor-core/" + location); InputStream inputStream = url.openConnection().getInputStream(); return Optional.of(new Image(Display.getCurrent(), inputStream)); } catch (IOException e) { return Optional.empty(); } } public static <T> T callGetter(Object element, String getterName, Class<T> returnType) { try { return returnType.cast(element.getClass().getMethod(getterName).invoke(element)); } catch (ClassCastException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | NoSuchMethodException | SecurityException e) { throw new IllegalArgumentException("Object of type " + element.getClass().getName() + "didn't have correctly typed, no-argument method called " + getterName, e); } } public static <T> Stream<T> preorder(T start, Function<T, Collection<? extends T>> generatingFunction) { List<T> elements = new ArrayList<>(); Stack<T> stack = new Stack<>(); stack.push(start); T currentElement; while (!stack.isEmpty()) { currentElement = stack.pop(); elements.add(currentElement); stack.addAll(generatingFunction.apply(currentElement)); } return elements.stream(); } public static <T> void traverse(T root, Function<T, Collection<? extends T>> childGenerator, Consumer<? super T> enter, Consumer<? super T> exit) { Set<T> previouslyVisited = new HashSet<>(); Stack<T> yetToVisit = new Stack<>(); yetToVisit.push(root); T nextElement; while (!yetToVisit.isEmpty()) { nextElement = yetToVisit.peek(); if (!previouslyVisited.contains(nextElement)) { enter.accept(nextElement); previouslyVisited.add(nextElement); yetToVisit.addAll(childGenerator.apply(nextElement)); } else { exit.accept(yetToVisit.pop()); } } } public static String getContents(IStorage storage) { try { return IOUtils.toString(storage.getContents()); } catch (IOException | CoreException e) { throw new RuntimeException(e); } } public static IStorageEditorInput getEditorInput(IStorage storage) { if (storage instanceof IFile) { return new FileEditorInput((IFile) storage); } else if (storage instanceof IJarEntryResource) { return new JarEntryEditorInput(storage); } else { throw new IllegalArgumentException("Unknown IStorage implementation"); } } public static IStorage getStorage(IEditorInput editorInput) { if (editorInput instanceof IStorageEditorInput) { try { return ((IStorageEditorInput) editorInput).getStorage(); } catch (CoreException e) { throw new RuntimeException(e); } } else { throw new IllegalArgumentException("Unknown IStorage implementation"); } } public static IProject getProject(IStorage storage) { if (storage instanceof IFile) { return ((IFile) storage).getProject(); } else if (storage instanceof IJarEntryResource) { return ((IJarEntryResource) storage).getPackageFragmentRoot().getJavaProject().getProject(); } else { throw new IllegalArgumentException("Unknown IStorage implementation"); } } public static void addToClasspath(IJavaProject javaProject, List<IClasspathEntry> newEntries) { try { IClasspathEntry[] oldClasspath = javaProject.getRawClasspath(); IClasspathEntry[] newClasspath = Arrays.copyOf(oldClasspath, oldClasspath.length + newEntries.size()); for (int i = 0; i < newEntries.size(); i++) { newClasspath[oldClasspath.length + i] = newEntries.get(i); } javaProject.setRawClasspath(newClasspath, null); } catch (JavaModelException e) { throw new RuntimeException(e); } } public static boolean removeFromClasspath(IJavaProject javaProject, Predicate<IClasspathEntry> predicate) { try { IClasspathEntry[] oldClasspath = javaProject.getRawClasspath(); List<IClasspathEntry> filteredClasspath = Arrays.stream(oldClasspath).filter(predicate.negate()) .collect(Collectors.toList()); IClasspathEntry[] newClasspath = filteredClasspath .toArray(new IClasspathEntry[filteredClasspath.size()]); javaProject.setRawClasspath(newClasspath, null); return oldClasspath.length > newClasspath.length; } catch (JavaModelException e) { throw new RuntimeException(e); } } public static int convertLineAndColumnToLinearIndex(String string, int line, int column) { String[] lines = string.split("\n"); if (lines.length <= line) { return 0; } else { int linearIndex = 0; for (int i = 0; i < line - 1; i++) { linearIndex += lines[i].length() + 1; } linearIndex += column; return linearIndex; } } }