Re: extract text from a PDF file with JAVA

From:
"Sergio" <boser87@hotmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
2 Aug 2006 11:38:00 -0700
Message-ID:
<1154543880.477999.211030@i3g2000cwc.googlegroups.com>

    Please show the parse method of the file com.etymon.pj.PdfParser. Be
sure to include line 427.

    - Oliver


As you've requested here is the parse method of the file
com.etymon.pj.PdfParser.
It's quite long...the line 427 is the return instruction at the end of
method.
Thanks again.

    public static PjObject parse(Pdf pdf, RandomAccessFile raf, long[][]
xref, byte[] data, int start)
        throws IOException, PjException {
        PdfParserState state = new PdfParserState();
        state._data = data;
        state._pos = start;
        state._stream = -1;
        Stack stack = new Stack();
        boolean endFlag = false;
        while ( ( ! endFlag ) && (getToken(state)) ) {
            if (state._stream != -1) {
                stack.push(state._streamToken);
                state._stream = -1;
            }
            else if (state._token.equals("startxref")) {
                endFlag = true;
            }
            else if (state._token.equals("endobj")) {
                endFlag = true;
            }
            else if (state._token.equals("%%EOF")) {
                endFlag = true;
            }
            else if (state._token.equals("endstream")) {
                byte[] stream = (byte[])(stack.pop());
                PjStreamDictionary pjsd = new PjStreamDictionary(
                    ((PjDictionary)(stack.pop())).getHashtable());
                PjStream pjs = new PjStream(pjsd, stream);
                stack.push(pjs);
            }
            else if (state._token.equals("stream")) {
                // get length of stream
                PjObject obj = ((PjObject)(
                    (((PjDictionary)(stack.peek())).
                    getHashtable().
                            get(new PjName("Length")))));
                if (obj instanceof PjReference) {
                    obj = getObject(pdf, raf, xref,
                            ((PjReference)(obj)).getObjNumber().getInt());
                }
                state._stream =
                    ((PjNumber)(obj)).getInt();

                // the following if() clause added to
                // handle the case of "Length" being
                // incorrect (larger than the actual
                // stream length)
                if ( state._stream >
                     (state._data.length - state._pos)
                    ) {
                    state._stream =
                        state._data.length -
                        state._pos - 17;
                }

                if (state._pos < state._data.length) {
                    if ((char)(state._data[state._pos]) == '\r') {
                        state._pos++;
                    }
                    if ( (state._pos < state._data.length) &&
                         ((char)(state._data[state._pos]) ==
                          '\n') ) {
                        state._pos++;
                    }
                }
            }
            else if (state._token.equals("null")) {
                stack.push(new PjNull());
            }
            else if (state._token.equals("true")) {
                stack.push(new PjBoolean(true));
            }
            else if (state._token.equals("false")) {
                stack.push(new PjBoolean(false));
            }
            else if (state._token.equals("R")) {
                // we ignore the generation number
                // because all objects get reset to
                // generation 0 when we collapse the
                // incremental updates
                stack.pop(); // the generation number
                PjNumber obj = (PjNumber)(stack.pop());
                stack.push(new PjReference(obj, PjNumber.ZERO));
            }
            else if ( (state._token.charAt(0) == '<') &&
                  (state._token.startsWith("<<") == false) ) {
                stack.push(new PjString(PjString.decodePdf(state._token)));
            }
            else if (
                (Character.isDigit(state._token.charAt(0)))
                || (state._token.charAt(0) == '-')
                || (state._token.charAt(0) == '.') ) {
                stack.push(new PjNumber(new Float(state._token).floatValue()));
            }
            else if (state._token.charAt(0) == '(') {
                stack.push(new PjString(PjString.decodePdf(state._token)));
            }
            else if (state._token.charAt(0) == '/') {
                stack.push(new PjName(state._token.substring(1)));
            }
            else if (state._token.equals(">>")) {
                boolean done = false;
                Object obj;
                Hashtable h = new Hashtable();
                while ( ! done ) {
                    obj = stack.pop();
                    if ( (obj instanceof String) &&
                         (((String)obj).equals("<<")) ) {
                        done = true;
                    } else {
                        h.put((PjName)(stack.pop()),
                              (PjObject)obj);
                    }
                }
                // figure out what kind of dictionary we have
                PjDictionary dictionary = new PjDictionary(h);
                if (PjPage.isLike(dictionary)) {
                    stack.push(new PjPage(h));
                }
                else if (PjPages.isLike(dictionary)) {
                    stack.push(new PjPages(h));
                }
                else if (PjFontType1.isLike(dictionary)) {
                    stack.push(new PjFontType1(h));
                }
                else if (PjFontDescriptor.isLike(dictionary)) {
                    stack.push(new PjFontDescriptor(h));
                }
                else if (PjResources.isLike(dictionary)) {
                    stack.push(new PjResources(h));
                }
                else if (PjCatalog.isLike(dictionary)) {
                    stack.push(new PjCatalog(h));
                }
                else if (PjInfo.isLike(dictionary)) {
                    stack.push(new PjInfo(h));
                }
                else if (PjEncoding.isLike(dictionary)) {
                    stack.push(new PjEncoding(h));
                }
                else {
                    stack.push(dictionary);
                }
            }
            else if (state._token.equals("]")) {
                boolean done = false;
                Object obj;
                Vector v = new Vector();
                while ( ! done ) {
                    obj = stack.pop();
                    if ( (obj instanceof String) &&
                         (((String)obj).equals("[")) ) {
                        done = true;
                    } else {
                        v.insertElementAt((PjObject)obj, 0);
                    }
                }
                // figure out what kind of array we have
                PjArray array = new PjArray(v);
                if (PjRectangle.isLike(array)) {
                    stack.push(new PjRectangle(v));
                }
                else if (PjProcSet.isLike(array)) {
                    stack.push(new PjProcSet(v));
                }
                else {
                    stack.push(array);
                }
            }
            else if (state._token.startsWith("%")) {
                // do nothing
            }
            else {
                stack.push(state._token);
            }
        }
    /*line 427*/ return (PjObject)(stack.pop());
    }

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