?? codeviewer.java
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/**
* $RCSfile: CodeViewer.java,v $
* $Revision: 1.7 $
* $Date: 2001/07/31 05:39:19 $
*
* Copyright (C) 1999-2001 CoolServlets, Inc. All rights reserved.
*
* This software is the proprietary information of CoolServlets, Inc.
* Use is subject to license terms.
*/
package net.acai.codeviewer;
import java.util.*;
/**
* A class that syntax highlights Java code into html.
* <p>
* 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.
* <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:
* <p>
* <pre>
* htmlFilter
* |__
* multiLineCommentFilter
* |___
* inlineCommentFilter
* |___
* stringFilter
* |__
* keywordFilter
* </pre>
*
*/
public class CodeViewer {
private static HashMap reservedWords = new HashMap(150); // >= Java2 only (also, not thread-safe)
//private static Hashtable reservedWords = new Hashtable(150); // < Java2 (thread-safe)
private boolean inMultiLineComment = false;
private String backgroundColor = "#ffffff";
private String commentStart = "<font color=\"#aa0000\"><i>";
private String commentEnd = "</font></i>";
private String stringStart = "<font color=\"#000099\">";
private String stringEnd = "</font>";
private String reservedWordStart = "<b>";
private String reservedWordEnd = "</b>";
/**
* Load all keywords at class loading time.
*/
static {
loadKeywords();
}
/**
* Gets the html for the start of a comment block.
*/
public String getCommentStart() {
return commentStart;
}
/**
* Sets the html for the start of a comment block.
*/
public void setCommentStart(String commentStart) {
this.commentStart = commentStart;
}
/**
* Gets the html for the end of a comment block.
*/
public String getCommentEnd() {
return commentEnd;
}
/**
* Sets the html for the end of a comment block.
*/
public void setCommentEnd(String commentEnd) {
this.commentEnd = commentEnd;
}
/**
* Gets the html for the start of a String.
*/
public String getStringStart() {
return stringStart;
}
/**
* Sets the html for the start of a String.
*/
public void setStringStart(String stringStart) {
this.stringStart = stringStart;
}
/**
* Gets the html for the end of a String.
*/
public String getStringEnd() {
return stringEnd;
}
/**
* Sets the html for the end of a String.
*/
public void setStringEnd(String stringEnd) {
this.stringEnd = stringEnd;
}
/**
* Gets the html for the start of a reserved word.
*/
public String getReservedWordStart() {
return reservedWordStart;
}
/**
* Sets the html for the start of a reserved word.
*/
public void setReservedWordStart(String reservedWordStart) {
this.reservedWordStart = reservedWordStart;
}
/**
* Gets the html for the end of a reserved word.
*/
public String getReservedWordEnd() {
return reservedWordEnd;
}
/**
* Sets the html for the end of a reserved word.
*/
public void setReservedWordEnd(String reservedWordEnd) {
this.reservedWordEnd = 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 that appear in the java source into more benign text
* that won't disrupt the output.
*/
private String htmlFilter( String line ) {
if( line == null || line.equals("") ) {
return "";
}
// replace ampersands with HTML escape sequence for ampersand;
line = replace(line, "&", "&");
// replace \" sequences with HTML escape sequences;
line = replace(line, "\\\"", "\"");
// replace the \\ with HTML escape sequences. fixes a problem when
// backslashes preceed quotes.
line = replace(line, "\\\\", "\\" );
// 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();
}
/**
* Replaces all instances of oldString with newString in line.
*/
private static final String replace( String line, String oldString, String newString )
{
int i=0;
if ((i=line.indexOf(oldString, i)) >= 0 ) {
char [] line2 = line.toCharArray();
char [] newString2 = newString.toCharArray();
int oLength = oldString.length();
StringBuffer buf = new StringBuffer(line2.length);
buf.append(line2, 0, i).append(newString2);
i += oLength;
int j = i;
while((i=line.indexOf(oldString, i)) > 0 ) {
buf.append(line2, j, i-j).append(newString2);
i += oLength;
j = i;
}
buf.append(line2, j, line2.length - j);
return buf.toString();
}
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. Improved list
* in version 1.1 taken directly from Java language spec.
*/
private static void loadKeywords() {
reservedWords.put("abstract", "abstract");
reservedWords.put("boolean", "boolean");
reservedWords.put("break", "break");
reservedWords.put("byte", "byte");
reservedWords.put("case", "case");
reservedWords.put("catch", "catch");
reservedWords.put("char", "char");
reservedWords.put("class", "class");
reservedWords.put("const", "const");
reservedWords.put("continue", "continue");
reservedWords.put("default", "default");
reservedWords.put("do", "do");
reservedWords.put("double", "double");
reservedWords.put("else", "else");
reservedWords.put("extends", "extends");
reservedWords.put("false", "false");
reservedWords.put("final", "final");
reservedWords.put("finally", "finally");
reservedWords.put("float", "float");
reservedWords.put("for", "for");
reservedWords.put("goto", "goto");
reservedWords.put("if", "if");
reservedWords.put("implements", "implements");
reservedWords.put("import", "import");
reservedWords.put("instanceof", "instanceof");
reservedWords.put("int", "int");
reservedWords.put("interface", "interface");
reservedWords.put("long", "long");
reservedWords.put("native", "native");
reservedWords.put("new", "new");
reservedWords.put("package", "package");
reservedWords.put("private", "private");
reservedWords.put("protected", "protected");
reservedWords.put("public", "public");
reservedWords.put("return", "return");
reservedWords.put("short", "short");
reservedWords.put("static", "static");
reservedWords.put("strictfp", "strictfp");
reservedWords.put("super", "super");
reservedWords.put("switch", "switch");
reservedWords.put("synchronized", "synchronized");
reservedWords.put("this", "this");
reservedWords.put("throw", "throw");
reservedWords.put("throws", "throws");
reservedWords.put("transient", "transient");
reservedWords.put("true", "true");
reservedWords.put("try", "try");
reservedWords.put("void", "void");
reservedWords.put("volatile", "volatile");
reservedWords.put("while", "while");
}
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