MiscUtil.java

/*
 * Copyright (C) 2016 Patrick Favre-Bulle
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package at.favre.tools.dconvert.util;

import java.io.File;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Locale;
import java.util.Set;

/**
 * Misc util methods
 */
public class MiscUtil {
	public static String getStackTrace(Throwable t) {
		StringWriter sw = new StringWriter();
		PrintWriter pw = new PrintWriter(sw);
		t.printStackTrace(pw);
		return sw.toString();
	}

	public static String duration(long ms) {
		if (ms >= 1000) {
			return String.format(Locale.US, "%.2f sec", (double) ms / 1000);
		}
		return ms + " ms";
	}

	public static <T> T[] concat(T[] first, T[] second) {
		T[] result = Arrays.copyOf(first, first.length + second.length);
		System.arraycopy(second, 0, result, first.length, second.length);
		return result;
	}

	public static File createAndCheckFolder(String path, boolean dryRun) {
		File f = new File(path);

		if (dryRun) {
			return f;
		}

		if (!f.exists()) {
			f.mkdirs();
		}

		if (!f.exists() || !f.isDirectory()) {
			throw new IllegalStateException("could not create folder: " + path);
		}
		return f;
	}

	public static String getFileExtensionLowerCase(File file) {
		return getFileExtension(file).toLowerCase();
	}

	public static String getFileExtension(File file) {
		if (file == null) {
			return "";
		}
		return file.getName().substring(file.getName().lastIndexOf(".") + 1);
	}

	public static String getFileNameWithoutExtension(File file) {
		String fileName = file.getName();
		int pos = fileName.lastIndexOf(".");
		if (pos > 0) {
			fileName = fileName.substring(0, pos);
		}
		return fileName;
	}

	public static String getCmdProgressBar(float progress) {
		int loadingBarCount = 40;
		int bars = Math.round((float) loadingBarCount * progress);
		StringBuilder sb = new StringBuilder("\r[");

		for (int i = 0; i < loadingBarCount; i++) {
			if (i < bars) {
				sb.append("-");
			} else {
				sb.append(" ");
			}
		}
		sb.append("] ");

		if (progress < 1f) {
			sb.append(String.format("%6s", String.format(Locale.US, "%.2f", progress * 100f))).append("%");
		} else {
			sb.append("100.00%\n");
		}

		return sb.toString();
	}

	public static <T> Set<T> toSet(T elem) {
		Set<T> set = new HashSet<>(1);
		set.add(elem);
		return set;
	}

	public static void deleteFolder(File folder) {
		if (folder != null && folder.exists()) {
			File[] files = folder.listFiles();
			if (files != null) { //some JVMs return null for empty dirs
				for (File f : files) {
					if (f.isDirectory()) {
						deleteFolder(f);
					} else {
						f.delete();
					}
				}
			}
			folder.delete();
		}
	}
}