/**
* 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.
*
*/
import java.io.*;
import java.util.*;
/**
* A class that syntax highlights Java code by turning it into html.
*
* @version 1.0 October 1999
* @author Bill Lynch, Matt Tucker, CoolServlets.com
*
* <p> A <code>CodeViewer</code> 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.
*
* <p> Users of the class can set how the java code will be highlighted with
* setter methods.
*
* <p> Only valid java lines should be passed in since the object maintains
* state and may not handle illegal code gracefully.
*
* <p> The actual system is implemented as a series of filters that deal with
* specific portions of the java code. The filters are as follows:
*
* <pre>
* htmlFilter
* |__
* multiLineCommentFilter
* |___
* inlineCommentFilter
* |___
* stringFilter
* |__
* keywordFilter
* </pre>
*/
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 = "</font><font size=1 color=\"#0000aa\"><i>";
private String commentEnd = "</font></i><font size=1 color=black>";
private String stringStart = "</font><font size=1 color=\"#00bb00\">";
private String stringEnd = "</font><font size=1 color=black>";
private String reservedWordStart = "<b>";
private String reservedWordEnd = "</b>";
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<line.length() && ( ( ch >= 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" );
}
}
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