Java tutorial
/* * Copyright 1999,2004,2012 The Apache Software Foundation. * * 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. */ // Copied from GenerationJava Core Library. //package com.generationjava.lang; // copied in kune from: // http://svn.apache.org/repos/asf/jakarta/taglibs/proper/string/trunk/src/org/apache/taglibs/string/util/StringW.java package cc.kune.core.server.utils; import org.apache.commons.lang.StringUtils; // TODO: Auto-generated Javadoc /** * A set of String library static methods. While extending String or * StringBuffer would have been the nicest solution, that is not possible, so a * simple set of static methods seems the most workable. * * Method ideas have so far been taken from the PHP4, Ruby and .NET languages. * * @author bayard@generationjava.com * @version 0.4 20010812 */ final public class StringW { /** * Quote a string so that it may be used in a regular expression without any * parts of the string being considered as a part of the regular expression's * control characters. * * @param str * the str * @return the string */ static public String quoteRegularExpression(final String str) { // replace ? + * / . ^ $ as long as they're not in character // class. so must be done by hand final char[] chrs = str.toCharArray(); final int sz = chrs.length; final StringBuffer buffer = new StringBuffer(2 * sz); for (int i = 0; i < sz; i++) { switch (chrs[i]) { case '[': case ']': case '?': case '+': case '*': case '/': case '.': case '^': case '$': buffer.append("\\"); default: buffer.append(chrs[i]); } } return buffer.toString(); } /** * Truncates a string nicely. It will search for the first space after the * lower limit and truncate the string there. It will also append any string * passed as a parameter to the end of the string. The hard limit can be * specified to forcibily truncate a string (in the case of an extremely long * word or such). All HTML/XML markup will be stripped from the string prior * to processing for truncation. * * @param str * String the string to be truncated. * @param lower * int value of the lower limit. * @param upper * int value of the upper limit, -1 if no limit is desired. If the * uppper limit is lower than the lower limit, it will be adjusted to * be same as the lower limit. * @param appendToEnd * String to be appended to the end of the truncated string. This is * appended ONLY if the string was indeed truncated. The append is * does not count towards any lower/upper limits. * @return the string * @author timster@mac.com */ // @PMD:REVIEWED:AvoidReassigningParameters: by vjrj on 21/05/09 14:13 public static String truncateNicely(String str, final int lower, int upper, final String appendToEnd) { // strip markup from the string str = XmlW.removeXml(str); // unescape temporarily for length handling str = XmlW.unescapeXml(str); // quickly adjust the upper if it is set lower than 'lower' if (upper < lower) { upper = lower; } // now determine if the string fits within the upper limit // if it does, go straight to return, do not pass 'go' and collect $200 if (str.length() > upper) { // the magic location int int loc; // first we determine where the next space appears after lower loc = str.lastIndexOf(' ', upper); // now we'll see if the location is greater than the lower limit if (loc >= lower) { // yes it was, so we'll cut it off here str = str.substring(0, loc); } else { // no it wasnt, so we'll cut it off at the upper limit str = str.substring(0, upper); } // the string was truncated, so we append the appendToEnd String str = str + appendToEnd; } // escape after finished processing string str = XmlW.escapeXml(str); return str; } /** * Create a word-wrapped version of a String. Wrap at 80 characters and use * newlines as the delimiter. If a word is over 80 characters long use a - * sign to split it. * * @param str * the str * @return the string */ static public String wordWrap(final String str) { return wordWrap(str, 80, "\n", "-", true); } /** * Create a word-wrapped version of a String. Wrap at a specified width and * use newlines as the delimiter. If a word is over the width in lenght use a * - sign to split it. * * @param str * the str * @param width * the width * @return the string */ static public String wordWrap(final String str, final int width) { return wordWrap(str, width, "\n", "-", true); } /** * Word-wrap a string. * * @param str * String to word-wrap * @param width * int to wrap at * @param delim * String to use to separate lines * @param split * String to use to split a word greater than width long * * @return String that has been word wrapped (with the delim inside width * boundaries) */ static public String wordWrap(final String str, final int width, final String delim, final String split) { return wordWrap(str, width, delim, split, true); } /** * Word-wrap a string. * * @param str * String to word-wrap * @param width * int to wrap at * @param delim * String to use to separate lines * @param split * String to use to split a word greater than width long * @param delimInside * wheter or not delim should be included in chunk before length * reaches width. * * @return String that has been word wrapped */ // @PMD:REVIEWED:AvoidReassigningParameters: by vjrj on 21/05/09 14:13 static public String wordWrap(final String str, int width, final String delim, final String split, final boolean delimInside) { final int sz = str.length(); // System.err.println( ">>>> inside: " + delimInside + " sz : " + sz ); // / shift width up one. mainly as it makes the logic easier width++; // our best guess as to an initial size final StringBuffer buffer = new StringBuffer(sz / width * delim.length() + sz); // every line might include a delim on the end // System.err.println( "width before: "+ width ); if (delimInside) { width = width - delim.length(); } else { width--; } // System.err.println( "width after: "+ width ); int idx = -1; String substr = null; // beware: i is rolled-back inside the loop for (int i = 0; i < sz; i += width) { // on the last line if (i > sz - width) { buffer.append(str.substring(i)); // System.err.print("LAST-LINE: "+str.substring(i)); break; } // System.err.println("loop[i] is: "+i); // the current line substr = str.substring(i, i + width); // System.err.println( "substr: " + substr ); // is the delim already on the line idx = substr.indexOf(delim); // System.err.println( "i: " + i + " idx : " + idx ); if (idx != -1) { buffer.append(substr.substring(0, idx)); // System.err.println("Substr: '"substr.substring(0,idx)+"'"); buffer.append(delim); i -= width - idx - delim.length(); // System.err.println("loop[i] is now: "+i); // System.err.println("ounfd-whitespace: '"+substr.charAt(idx+1)+"'."); // Erase a space after a delim. Is this too obscure? if (substr.length() > idx + 1) { if (substr.charAt(idx + 1) != '\n') { if (Character.isWhitespace(substr.charAt(idx + 1))) { i++; } } } // System.err.println("i -= "+width+"-"+idx); continue; } idx = -1; // figure out where the last space is final char[] chrs = substr.toCharArray(); for (int j = width; j > 0; j--) { if (Character.isWhitespace(chrs[j - 1])) { idx = j; // System.err.println("Found whitespace: "+idx); break; } } // idx is the last whitespace on the line. // System.err.println("idx is "+idx); if (idx == -1) { for (int j = width; j > 0; j--) { if (chrs[j - 1] == '-') { idx = j; // System.err.println("Found Dash: "+idx); break; } } if (idx == -1) { buffer.append(substr); buffer.append(delim); // System.err.print(substr); // System.err.print(delim); } else { if (idx != width) { idx++; } buffer.append(substr.substring(0, idx)); buffer.append(delim); // System.err.print(substr.substring(0,idx)); // System.err.print(delim); i -= width - idx; } } else { /* * if(force) { if(idx == width-1) { buffer.append(substr); * buffer.append(delim); } else { // stick a split in. int splitsz = * split.length(); buffer.append(substr.substring(0,width-splitsz)); * buffer.append(split); buffer.append(delim); i -= splitsz; } } else { */ // insert spaces buffer.append(substr.substring(0, idx)); buffer.append(StringUtils.repeat(" ", width - idx)); // System.err.print(substr.substring(0,idx)); // System.err.print(StringUtils.repeat(" ",width-idx)); buffer.append(delim); // System.err.print(delim); // System.err.println("i -= "+width+"-"+idx); i -= width - idx; // } } } // System.err.println("\n*************"); return buffer.toString(); } }