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JspReader.javaAPI DocGlassfish v2 API16719Fri May 04 22:32:52 BST 2007org.apache.jasper.compiler

JspReader

public class JspReader extends Object
JspReader is an input buffer for the JSP parser. It should allow unlimited lookahead and pushback. It also has a bunch of parsing utility methods for understanding htmlesque thingies.
author
Anil K. Vijendran
author
Anselm Baird-Smith
author
Harish Prabandham
author
Rajiv Mordani
author
Mandar Raje
author
Danno Ferrin
author
Kin-man Chung
author
Shawn Bayern
author
Mark Roth

Fields Summary
private static com.sun.org.apache.commons.logging.Log
log
private Mark
current
private String
master
private Vector
sourceFiles
private int
currFileId
private int
size
private org.apache.jasper.JspCompilationContext
context
private ErrorDispatcher
err
private boolean
singleFile
Constructors Summary
public JspReader(org.apache.jasper.JspCompilationContext ctxt, String fname, String encoding, JarFile jarFile, ErrorDispatcher err)


    /*
     * Constructor.
     */
      
		      
		      
		      
		      
	        

	this(ctxt, fname, encoding,
	     JspUtil.getReader(fname, encoding, jarFile, ctxt, err),
	     err);
    
public JspReader(org.apache.jasper.JspCompilationContext ctxt, String fname, String encoding, InputStreamReader reader, ErrorDispatcher err)


        this.context = ctxt;
	this.err = err;
	sourceFiles = new Vector();
	currFileId = 0;
	size = 0;
	singleFile = false;
	pushFile(fname, encoding, reader);
    
Methods Summary
java.lang.StringgetFile(int fileid)

	return (String) sourceFiles.elementAt(fileid);
    
org.apache.jasper.JspCompilationContextgetJspCompilationContext()

        return context;
    
java.net.URLgetResource(java.lang.String path)
Gets the URL for the given path name.

param
path Path name
return
URL for the given path name.
exception
MalformedURLException if the path name is not given in the correct form

        return context.getResource(path);
    
java.lang.StringgetText(Mark start, Mark stop)

	Mark oldstart = mark();
	reset(start);
	CharArrayWriter caw = new CharArrayWriter();
	while (!stop.equals(mark()))
	    caw.write(nextChar());
	caw.close();
	reset(oldstart);
	return caw.toString();
    
booleanhasMoreInput()

	if (current.cursor >= current.stream.length) {
            if (singleFile) return false; 
	    while (popFile()) {
		if (current.cursor < current.stream.length) return true;
	    }
	    return false;
	}
	return true;
    
private booleanisDelimiter()
Parse utils - Is current character a token delimiter ? Delimiters are currently defined to be =, >, <, ", and ' or any any space character as defined by isSpace.

return
A boolean.

	if (! isSpace()) {
	    int ch = peekChar();
	    // Look for a single-char work delimiter:
	    if (ch == '=" || ch == '>" || ch == '"" || ch == '\'"
		    || ch == '/") {
		return true;
	    }
	    // Look for an end-of-comment or end-of-tag:		
	    if (ch == '-") {
		Mark mark = mark();
		if (((ch = nextChar()) == '>")
		        || ((ch == '-") && (nextChar() == '>"))) {
		    reset(mark);
		    return true;
		} else {
		    reset(mark);
		    return false;
		}
	    }
	    return false;
	} else {
	    return true;
	}
    
final booleanisSpace()

        // Note: If this logic changes, also update Node.TemplateText.rtrim()
	return peekChar() <= ' ";
    
Markmark()

	return new Mark(current);
    
booleanmatches(java.lang.String string)
search the stream for a match to a string

param
string The string to match
return
true is one is found, the current position in stream is positioned after the search string, false otherwise, position in stream unchanged.

	Mark mark = mark();
	int ch = 0;
	int i = 0;
	do {
	    ch = nextChar();
	    if (((char) ch) != string.charAt(i++)) {
		reset(mark);
		return false;
	    }
	} while (i < string.length());
	return true;
    
booleanmatchesETag(java.lang.String tagName)

	Mark mark = mark();

	if (!matches("</" + tagName))
	    return false;
	skipSpaces();
	if (nextChar() == '>")
	    return true;

	reset(mark);
	return false;
    
booleanmatchesETagWithoutLessThan(java.lang.String tagName)

       Mark mark = mark();

       if (!matches("/" + tagName))
           return false;
       skipSpaces();
       if (nextChar() == '>")
           return true;

       reset(mark);
       return false;
    
booleanmatchesIgnoreCase(java.lang.String string)

	Mark mark = mark();
	int ch = 0;
	int i = 0;
	do {
	    ch = nextChar();
	    if (Character.toLowerCase((char) ch) != string.charAt(i++)) {
		reset(mark);
		return false;
	    }
	} while (i < string.length());
	reset(mark);
	return true;
    
booleanmatchesOptionalSpacesFollowedBy(java.lang.String s)
Looks ahead to see if there are optional spaces followed by the given String. If so, true is returned and those spaces and characters are skipped. If not, false is returned and the position is restored to where we were before.

        Mark mark = mark();

        skipSpaces();
        boolean result = matches( s );
        if( !result ) {
            reset( mark );
        }

        return result;
    
intnextChar()

	if (!hasMoreInput())
	    return -1;
	
	int ch = current.stream[current.cursor];

	current.cursor++;
	
	if (ch == '\n") {
	    current.line++;
	    current.col = 0;
	} else {
	    current.col++;
	}
	return ch;
    
java.lang.StringparseToken(boolean quoted)
Parse a space delimited token. If quoted the token will consume all characters up to a matching quote, otherwise, it consumes up to the first delimiter character.

param
quoted If true accept quoted strings.

	StringBuffer stringBuffer = new StringBuffer();
	skipSpaces();
	stringBuffer.setLength(0);
	
        if (!hasMoreInput()) {
            return "";
        }

	int ch = peekChar();
	
	if (quoted) {
	    if (ch == '"" || ch == '\'") {

		char endQuote = ch == '"" ? '"" : '\'";
		// Consume the open quote: 
		ch = nextChar();
		for (ch = nextChar(); ch != -1 && ch != endQuote;
		         ch = nextChar()) {
		    if (ch == '\\") 
			ch = nextChar();
		    stringBuffer.append((char) ch);
		}
		// Check end of quote, skip closing quote:
		if (ch == -1) {
		    err.jspError(mark(), "jsp.error.quotes.unterminated");
		}
	    } else {
		err.jspError(mark(), "jsp.error.attr.quoted");
	    }
	} else {
	    if (!isDelimiter()) {
		// Read value until delimiter is found:
		do {
		    ch = nextChar();
		    // Take care of the quoting here.
		    if (ch == '\\") {
			if (peekChar() == '"" || peekChar() == '\'" ||
			       peekChar() == '>" || peekChar() == '%")
			    ch = nextChar();
		    }
		    stringBuffer.append((char) ch);
		} while (!isDelimiter());
	    }
	}

	return stringBuffer.toString();
    
intpeekChar()

        if (!hasMoreInput())
            return -1;
	return current.stream[current.cursor];
    
private booleanpopFile()
Pop a file from the file stack. The field "current" is retored to the value to point to the previous files, if any, and is set to null otherwise.

return
true is there is a previous file on the stck. false otherwise.


	// Is stack created ? (will happen if the Jsp file we're looking at is
	// missing.
	if (current == null || currFileId < 0) {
	    return false;
	}

	// Restore parser state:
	String fName = getFile(currFileId);
	currFileId = unregisterSourceFile(fName);
	if (currFileId < -1) {
	    err.jspError("jsp.error.file.not.registered", fName);
	}

	Mark previous = current.popStream();
	if (previous != null) {
	    master = current.baseDir;
	    current = previous;
	    return true;
	}
	// Note that although the current file is undefined here, "current"
	// is not set to null just for convience, for it maybe used to
	// set the current (undefined) position.
	return false;
    
voidpushChar()
Back up the current cursor by one char, assumes current.cursor > 0, and that the char to be pushed back is not '\n'.

	current.cursor--;
	current.col--;
    
private voidpushFile(java.lang.String file, java.lang.String encoding, java.io.InputStreamReader reader)
Push a file (and its associated Stream) on the file stack. THe current position in the current file is remembered.


	// Register the file
	String longName = file;

	int fileid = registerSourceFile(longName);

        if (fileid == -1) {
            err.jspError("jsp.error.file.already.registered", file);
	}

	currFileId = fileid;

	try {
	    CharArrayWriter caw = new CharArrayWriter();
	    char buf[] = new char[1024];
	    for (int i = 0 ; (i = reader.read(buf)) != -1 ;)
		caw.write(buf, 0, i);
	    caw.close();
	    if (current == null) {
		current = new Mark(this, caw.toCharArray(), fileid, 
				   getFile(fileid), master, encoding);
	    } else {
		current.pushStream(caw.toCharArray(), fileid, getFile(fileid),
				   longName, encoding);
	    }
	} catch (Throwable ex) {
	    log.error("Exception parsing file ", ex);
	    // Pop state being constructed:
	    popFile();
	    err.jspError("jsp.error.file.cannot.read", file);
	} finally {
	    if (reader != null) {
		try {
		    reader.close();
		} catch (Exception any) {}
	    }
	}
    
private intregisterSourceFile(java.lang.String file)
Register a new source file. This method is used to implement file inclusion. Each included file gets a unique identifier (which is the index in the array of source files).

return
The index of the now registered file.

        if (sourceFiles.contains(file))
            return -1;
	sourceFiles.addElement(file);
	this.size++;
	return sourceFiles.size() - 1;
    
voidreset(Mark mark)

	current = new Mark(mark);
    
voidsetSingleFile(boolean val)

        singleFile = val;
    
intskipSpaces()

	int i = 0;
	while (hasMoreInput() && isSpace()) {
	    i++;
	    nextChar();
	}
	return i;
    
MarkskipUntil(java.lang.String limit)
Skip until the given string is matched in the stream. When returned, the context is positioned past the end of the match.

param
s The String to match.
return
A non-null Mark instance (positioned immediately before the search string) if found, null otherwise.

        Mark ret = null;
        int limlen = limit.length();
        int ch;

    skip:
        for (ret = mark(), ch = nextChar() ; ch != -1 ;
                 ret = mark(), ch = nextChar()) {
            if (ch == limit.charAt(0)) {
                Mark restart = mark();
                for (int i = 1 ; i < limlen ; i++) {
                    if (peekChar() == limit.charAt(i))
                        nextChar();
                    else {
                        reset(restart);
                        continue skip;
                    }
                }
                return ret;
            }
        }
        return null;
    
MarkskipUntilETag(java.lang.String tag)
Skip until the given end tag is matched in the stream. When returned, the context is positioned past the end of the tag.

param
tag The name of the tag whose ETag () to match.
return
A non-null Mark instance (positioned immediately before the ETag) if found, null otherwise.

	Mark ret = skipUntil("</" + tag);
	if (ret != null) {
	    skipSpaces();
	    if (nextChar() != '>")
		ret = null;
	}
	return ret;
    
MarkskipUntilIgnoreEsc(java.lang.String limit)
Skip until the given string is matched in the stream, but ignoring chars initially escaped by a '\'. When returned, the context is positioned past the end of the match.

param
s The String to match.
return
A non-null Mark instance (positioned immediately before the search string) if found, null otherwise.

	Mark ret = null;
	int limlen = limit.length();
	int ch;
	int prev = 'x";	// Doesn't matter
	
    skip:
	for (ret = mark(), ch = nextChar() ; ch != -1 ;
	         ret = mark(), prev = ch, ch = nextChar()) {	    
	    if (ch == '\\" && prev == '\\") {
		ch = 0;		// Double \ is not an escape char anymore
	    }
	    else if (ch == limit.charAt(0) && prev != '\\") {
		for (int i = 1 ; i < limlen ; i++) {
		    if (peekChar() == limit.charAt(i))
			nextChar();
		    else
			continue skip;
		}
		return ret;
	    }
	}
	return null;
    
private intunregisterSourceFile(java.lang.String file)
Unregister the source file. This method is used to implement file inclusion. Each included file gets a uniq identifier (which is the index in the array of source files).

return
The index of the now registered file.

        if (!sourceFiles.contains(file))
            return -1;
	sourceFiles.removeElement(file);
	this.size--;
	return sourceFiles.size() - 1;