Java tutorial
/******************************************************************************* * Copyright (c) 2006-2010 eBay Inc. All Rights Reserved. * 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 *******************************************************************************/ package org.ebayopensource.turmeric.eclipse.utils.lang; import java.text.MessageFormat; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import org.apache.commons.lang.StringUtils; /** * A utility class for working with <code>String</code>. * * @author yayu * */ public class StringUtil { /** The end of line. */ public static final String EOL; static { String eol = "\n"; EOL = StringUtils.isEmpty(System.getProperty("line.separator")) ? eol : System.getProperty("line.separator"); } /** * Remove the first occurrence of the giving string. * * @param string The string to be removed from * @param remove The string to be removed * @return the string */ public static String removeFirst(final String string, final String remove) { return StringUtils.replace(string, remove, "", 1); } /** * Join the objects using the given delimiter. * * @param objects the objects * @param delimiter the delimiter * @return the string */ public static String join(final Collection<? extends Object> objects, final String delimiter) { return StringUtils.join(objects != null ? objects.toArray() : null, delimiter); } /** * Copy non nulls. * * @param strings the String... elements to copy if not null * @return non-null String[] of non-null elements from input strings */ public static String[] copyNonNulls(final String... strings) { ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(strings)); arrayList.removeAll(Collections.singleton(null)); return arrayList.toArray(new String[0]); } /** * Chop. * * @param input the input * @param length the length * @param result the result */ public static void lineate(String input, int length, StringBuilder result) { int start = 0; while (length < (input.length() - start)) { int nextWhitespace = nextWhitespaceAfter(input, start, length); if (-1 == nextWhitespace) { result.append(input.substring(start)); result.append(EOL); start = input.length(); } else { result.append(input.substring(start, nextWhitespace)); result.append(EOL); start = nextWhitespace + 1; } } if (start < (input.length() - 1)) { result.append(input.substring(start)); result.append(EOL); } } /** * Next whitespace after. * * @param error the error * @param start the start * @param lineLength the line length * @return the int */ static int nextWhitespaceAfter(String error, int start, int lineLength) { final int LENGTH = error.length(); if ((null == error) || (start >= LENGTH)) { return -1; } int index = start + lineLength; while (index < LENGTH) { if (Character.isWhitespace(error.charAt(index))) { return index; } index++; } return -1; } /** * This method will prepend the prefix to the string arg iff prefix is not * already there at the beginning. * * @param prefix the prefix * @param string the string * @return the string */ public static String prefix(final String prefix, final String string) { if (StringUtils.isEmpty(prefix)) return string; if (StringUtils.defaultString(string).startsWith(prefix)) return StringUtils.defaultString(string); return prefix + StringUtils.defaultString(string); } /** * This method will postfix the postfix to the string arg iff prefix is not * already there at the end. * * @param string the string * @param postfix the postfix * @return the string */ public static String postfix(final String string, final String postfix) { if (StringUtils.isEmpty(postfix)) return string; if (StringUtils.defaultString(string).endsWith(postfix)) return StringUtils.defaultString(string); return StringUtils.defaultString(string) + postfix; } /** * Bracket. * * @param prefix the prefix * @param string the string * @param postfix the postfix * @return the string */ public static String bracket(final String prefix, final String string, final String postfix) { return postfix(prefix(prefix, string), postfix); } /** * <p> * </p>. * * @param messages the messages * @return A String to represent the message * @throws IllegalArgumentException the illegal argument exception */ public static String toString(Object... messages) throws IllegalArgumentException { final StringBuffer buf = new StringBuffer(); if (messages == null || messages.length == 0) { return buf.toString(); } for (Object msg : messages) { buf.append(String.valueOf(msg)); } return buf.toString(); } /** * Format the given message with the provided arguments. * * @param message the message * @param args the args * @return the string * @throws IllegalArgumentException the illegal argument exception * @see java.text.MessageFormat */ public static String formatString(String message, Object... args) throws IllegalArgumentException { if (args == null) return message; return MessageFormat.format(message, args); } /** * Broad equals. * * @param str1 the str1 * @param str2 the str2 * @return true, if successful * trims, ignores the case and null safe */ public static boolean broadEquals(String str1, String str2) { String defStr1 = StringUtils.defaultString(str1); String defStr2 = StringUtils.defaultString(str2); defStr1 = defStr1.trim(); defStr2 = defStr2.trim(); return defStr1.equalsIgnoreCase(defStr2); } }