Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * */ import java.io.IOException; import java.io.LineNumberReader; import java.io.PrintWriter; import java.io.StringReader; import java.io.StringWriter; import java.util.ArrayList; /** * Utility class for working with xml data * * Implementation is heavily based on org.apache.log4j.helpers.Transform * * @author The Apache MINA Project (dev@mina.apache.org) * @version $Rev: 686610 $, $Date: 2008-08-17 15:31:25 +0200 (Sun, 17 Aug 2008) $ */ public class Transform { private static final String CDATA_START = "<![CDATA["; private static final String CDATA_END = "]]>"; private static final String CDATA_PSEUDO_END = "]]>"; private static final String CDATA_EMBEDED_END = CDATA_END + CDATA_PSEUDO_END + CDATA_START; private static final int CDATA_END_LEN = CDATA_END.length(); /** * This method takes a string which may contain HTML tags (ie, * <b>, <table>, etc) and replaces any * '<', '>' , '&' or '"' * characters with respective predefined entity references. * * @param input The text to be converted. * @return The input string with the special characters replaced. * */ static public String escapeTags(final String input) { // Check if the string is null, zero length or devoid of special characters // if so, return what was sent in. if (input == null || input.length() == 0 || (input.indexOf('"') == -1 && input.indexOf('&') == -1 && input.indexOf('<') == -1 && input.indexOf('>') == -1)) { return input; } StringBuilder buf = new StringBuilder(input.length() + 6); char ch; int len = input.length(); for (int i = 0; i < len; i++) { ch = input.charAt(i); if (ch > '>') { buf.append(ch); } else if (ch == '<') { buf.append("<"); } else if (ch == '>') { buf.append(">"); } else if (ch == '&') { buf.append("&"); } else if (ch == '"') { buf.append("""); } else { buf.append(ch); } } return buf.toString(); } /** * Ensures that embeded CDEnd strings (]]>) are handled properly * within message, NDC and throwable tag text. * * @param buf StringBuffer holding the XML data to this point. The * initial CDStart (<![CDATA[) and final CDEnd (]]>) of the CDATA * section are the responsibility of the calling method. * @param str The String that is inserted into an existing CDATA Section within buf. * */ static public void appendEscapingCDATA(final StringBuffer buf, final String str) { if (str != null) { int end = str.indexOf(CDATA_END); if (end < 0) { buf.append(str); } else { int start = 0; while (end > -1) { buf.append(str.substring(start, end)); buf.append(CDATA_EMBEDED_END); start = end + CDATA_END_LEN; if (start < str.length()) { end = str.indexOf(CDATA_END, start); } else { return; } } buf.append(str.substring(start)); } } } /** * convert a Throwable into an array of Strings * @param throwable * @return string representation of the throwable */ public static String[] getThrowableStrRep(Throwable throwable) { StringWriter sw = new StringWriter(); PrintWriter pw = new PrintWriter(sw); throwable.printStackTrace(pw); pw.flush(); LineNumberReader reader = new LineNumberReader(new StringReader(sw.toString())); ArrayList<String> lines = new ArrayList<String>(); try { String line = reader.readLine(); while (line != null) { lines.add(line); line = reader.readLine(); } } catch (IOException ex) { lines.add(ex.toString()); } String[] rep = new String[lines.size()]; lines.toArray(rep); return rep; } }