/** * CodeViewer.java * * Bill Lynch & Matt Tucker * CoolServlets.com, October 1999 * * Please visit CoolServlets.com for high quality, open source Java servlets. * * Copyright (C) 1999 CoolServlets.com * * Any errors or suggested improvements to this class can be reported * as instructed on Coolservlets.com. We hope you enjoy * this program... your comments will encourage further development! * * This software is distributed under the terms of The BSD License. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * Neither name of CoolServlets.com nor the names of its contributors may be * used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY COOLSERVLETS.COM AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL COOLSERVLETS.COM OR CONTRIBUTORS BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * @(#)CodeViewer.java 1.6 02/06/13 */ import java.io.*; import java.util.*; /** * A class that syntax highlights Java code by turning it into html. * *

A CodeViewer object is created and then keeps state as * lines are passed in. Each line passed in as java text, is returned as syntax * highlighted html text. * *

Users of the class can set how the java code will be highlighted with * setter methods. * *

Only valid java lines should be passed in since the object maintains * state and may not handle illegal code gracefully. * *

The actual system is implemented as a series of filters that deal with * specific portions of the java code. The filters are as follows: * *

 *  htmlFilter
 *     |__
 *        multiLineCommentFilter
 *           |___
 *                inlineCommentFilter
 *                   |___
 *                        stringFilter
 *                           |__
 *                               keywordFilter
 * 
* * @version 1.6 06/13/02 * @author Bill Lynch, Matt Tucker, CoolServlets.com */ public class CodeViewer { private static HashMap reservedWords = new HashMap(); // >= Java2 only (also, not thread-safe) //private static Hashtable reservedWords = new Hashtable(); // < Java2 (thread-safe) private boolean inMultiLineComment = false; private String backgroundColor = "#ffffff"; private String commentStart = ""; private String commentEnd = ""; private String stringStart = ""; private String stringEnd = ""; private String reservedWordStart = ""; private String reservedWordEnd = ""; static { loadHash(); } public CodeViewer() { } public void setCommentStart(String commentStart) { this.commentStart = commentStart; } public void setCommentEnd(String commentEnd) { this.commentEnd = commentEnd; } public void setStringStart(String stringStart) { this.stringStart = stringStart; } public void setStringEnd(String stringEnd) { this.stringEnd = stringEnd; } public void setReservedWordStart(String reservedWordStart) { this.reservedWordStart = reservedWordStart; } public void setReservedWordEnd(String reservedWordEnd) { this.reservedWordEnd = reservedWordEnd; } public String getCommentStart() { return commentStart; } public String getCommentEnd() { return commentEnd; } public String getStringStart() { return stringStart; } public String getStringEnd() { return stringEnd; } public String getReservedWordStart() { return reservedWordStart; } public String getReservedWordEnd() { return reservedWordEnd; } /** * Passes off each line to the first filter. * @param line The line of Java code to be highlighted. */ public String syntaxHighlight( String line ) { return htmlFilter(line); } /* * Filter html tags into more benign text. */ private String htmlFilter( String line ) { if( line == null || line.equals("") ) { return ""; } // replace ampersands with HTML escape sequence for ampersand; line = replace(line, "&", "&"); // replace the \\ with HTML escape sequences. fixes a problem when // backslashes preceed quotes. line = replace(line, "\\\\", "\\" ); // replace \" sequences with HTML escape sequences; line = replace(line, "" + (char)92 + (char)34, "\""); // replace less-than signs which might be confused // by HTML as tag angle-brackets; line = replace(line, "<", "<"); // replace greater-than signs which might be confused // by HTML as tag angle-brackets; line = replace(line, ">", ">"); return multiLineCommentFilter(line); } /* * Filter out multiLine comments. State is kept with a private boolean * variable. */ private String multiLineCommentFilter(String line) { if (line == null || line.equals("")) { return ""; } StringBuffer buf = new StringBuffer(); int index; //First, check for the end of a multi-line comment. if (inMultiLineComment && (index = line.indexOf("*/")) > -1 && !isInsideString(line,index)) { inMultiLineComment = false; buf.append(line.substring(0,index)); buf.append("*/").append(commentEnd); if (line.length() > index+2) { buf.append(inlineCommentFilter(line.substring(index+2))); } return buf.toString(); } //If there was no end detected and we're currently in a multi-line //comment, we don't want to do anymore work, so return line. else if (inMultiLineComment) { return line; } //We're not currently in a comment, so check to see if the start //of a multi-line comment is in this line. else if ((index = line.indexOf("/*")) > -1 && !isInsideString(line,index)) { inMultiLineComment = true; //Return result of other filters + everything after the start //of the multiline comment. We need to pass the through the //to the multiLineComment filter again in case the comment ends //on the same line. buf.append(inlineCommentFilter(line.substring(0,index))); buf.append(commentStart).append("/*"); buf.append(multiLineCommentFilter(line.substring(index+2))); return buf.toString(); } //Otherwise, no useful multi-line comment information was found so //pass the line down to the next filter for processesing. else { return inlineCommentFilter(line); } } /* * Filter inline comments from a line and formats them properly. */ private String inlineCommentFilter(String line) { if (line == null || line.equals("")) { return ""; } StringBuffer buf = new StringBuffer(); int index; if ((index = line.indexOf("//")) > -1 && !isInsideString(line,index)) { buf.append(stringFilter(line.substring(0,index))); buf.append(commentStart); buf.append(line.substring(index)); buf.append(commentEnd); } else { buf.append(stringFilter(line)); } return buf.toString(); } /* * Filters strings from a line of text and formats them properly. */ private String stringFilter(String line) { if (line == null || line.equals("")) { return ""; } StringBuffer buf = new StringBuffer(); if (line.indexOf("\"") <= -1) { return keywordFilter(line); } int start = 0; int startStringIndex = -1; int endStringIndex = -1; int tempIndex; //Keep moving through String characters until we want to stop... while ((tempIndex = line.indexOf("\"")) > -1) { //We found the beginning of a string if (startStringIndex == -1) { startStringIndex = 0; buf.append( stringFilter(line.substring(start,tempIndex)) ); buf.append(stringStart).append("\""); line = line.substring(tempIndex+1); } //Must be at the end else { startStringIndex = -1; endStringIndex = tempIndex; buf.append(line.substring(0,endStringIndex+1)); buf.append(stringEnd); line = line.substring(endStringIndex+1); } } buf.append( keywordFilter(line) ); return buf.toString(); } /* * Filters keywords from a line of text and formats them properly. */ private String keywordFilter( String line ) { if( line == null || line.equals("") ) { return ""; } StringBuffer buf = new StringBuffer(); HashMap usedReservedWords = new HashMap(); // >= Java2 only (not thread-safe) //Hashtable usedReservedWords = new Hashtable(); // < Java2 (thread-safe) int i=0, startAt=0; char ch; StringBuffer temp = new StringBuffer(); while( i < line.length() ) { temp.setLength(0); ch = line.charAt(i); startAt = i; // 65-90, uppercase letters // 97-122, lowercase letters while( i= 65 && ch <= 90 ) || ( ch >= 97 && ch <= 122 ) ) ) { temp.append(ch); i++; if( i < line.length() ) { ch = line.charAt(i); } } String tempString = temp.toString(); if( reservedWords.containsKey(tempString) && !usedReservedWords.containsKey(tempString)) { usedReservedWords.put(tempString,tempString); line = replace( line, tempString, (reservedWordStart+tempString+reservedWordEnd) ); i += (reservedWordStart.length() + reservedWordEnd.length()); } else { i++; } } buf.append(line); return buf.toString(); } /* * All important replace method. Replaces all occurences of oldString in * line with newString. */ private String replace( String line, String oldString, String newString ) { int i=0; while( ( i=line.indexOf( oldString, i ) ) >= 0 ) { line = (new StringBuffer().append(line.substring(0,i)).append(newString).append(line.substring(i+oldString.length()))).toString(); i += newString.length(); } return line; } /* * Checks to see if some position in a line is between String start and * ending characters. Not yet used in code or fully working :) */ private boolean isInsideString(String line, int position) { if (line.indexOf("\"") < 0) { return false; } int index; String left = line.substring(0,position); String right = line.substring(position); int leftCount = 0; int rightCount = 0; while ((index = left.indexOf("\"")) > -1) { leftCount ++; left = left.substring(index+1); } while ((index = right.indexOf("\"")) > -1) { rightCount ++; right = right.substring(index+1); } if (rightCount % 2 != 0 && leftCount % 2 != 0) { return true; } else { return false; } } /* * Load Hashtable (or HashMap) with Java reserved words. */ private static void loadHash() { reservedWords.put( "abstract", "abstract" ); reservedWords.put( "do", "do" ); reservedWords.put( "inner", "inner" ); reservedWords.put( "public", "public" ); reservedWords.put( "var", "var" ); reservedWords.put( "boolean", "boolean" ); reservedWords.put( "continue", "continue" ); reservedWords.put( "int", "int" ); reservedWords.put( "return", "return" ); reservedWords.put( "void", "void" ); reservedWords.put( "break", "break" ); reservedWords.put( "else", "else" ); reservedWords.put( "interface", "interface" ); reservedWords.put( "short", "short" ); reservedWords.put( "volatile", "volatile" ); reservedWords.put( "byvalue", "byvalue" ); reservedWords.put( "extends", "extends" ); reservedWords.put( "long", "long" ); reservedWords.put( "static", "static" ); reservedWords.put( "while", "while" ); reservedWords.put( "case", "case" ); reservedWords.put( "final", "final" ); reservedWords.put( "naive", "naive" ); reservedWords.put( "super", "super" ); reservedWords.put( "transient", "transient" ); reservedWords.put( "cast", "cast" ); reservedWords.put( "float", "float" ); reservedWords.put( "new", "new" ); reservedWords.put( "rest", "rest" ); reservedWords.put( "catch", "catch" ); reservedWords.put( "for", "for" ); reservedWords.put( "null", "null" ); reservedWords.put( "synchronized", "synchronized" ); reservedWords.put( "char", "char" ); reservedWords.put( "finally", "finally" ); reservedWords.put( "operator", "operator" ); reservedWords.put( "this", "this" ); reservedWords.put( "class", "class" ); reservedWords.put( "generic", "generic" ); reservedWords.put( "outer", "outer" ); reservedWords.put( "switch", "switch" ); reservedWords.put( "const", "const" ); reservedWords.put( "goto", "goto" ); reservedWords.put( "package", "package" ); reservedWords.put( "throw", "throw" ); reservedWords.put( "double", "double" ); reservedWords.put( "if", "if" ); reservedWords.put( "private", "private" ); reservedWords.put( "true", "true" ); reservedWords.put( "default", "default" ); reservedWords.put( "import", "import" ); reservedWords.put( "protected", "protected" ); reservedWords.put( "try", "try" ); } }