pdfreader.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

     */
    public int getPageRotation(int index) {
        return getPageRotation(pageRefs.getPageNRelease(index));
    }

    int getPageRotation(PdfDictionary page) {
        PdfNumber rotate = (PdfNumber)getPdfObject(page.get(PdfName.ROTATE));
        if (rotate == null)
            return 0;
        else {
            int n = rotate.intValue();
            n %= 360;
            return n < 0 ? n + 360 : n;
        }
    }
    /** Gets the page size, taking rotation into account. This
     * is a <CODE>Rectangle</CODE> with the value of the /MediaBox and the /Rotate key.
     * @param index the page number. The first page is 1
     * @return a <CODE>Rectangle</CODE>
     */
    public Rectangle getPageSizeWithRotation(int index) {
        return getPageSizeWithRotation(pageRefs.getPageNRelease(index));
    }

    /**
     * Gets the rotated page from a page dictionary.
     * @param page the page dictionary
     * @return the rotated page
     */
    public Rectangle getPageSizeWithRotation(PdfDictionary page) {
        Rectangle rect = getPageSize(page);
        int rotation = getPageRotation(page);
        while (rotation > 0) {
            rect = rect.rotate();
            rotation -= 90;
        }
        return rect;
    }

    /** Gets the page size without taking rotation into account. This
     * is the value of the /MediaBox key.
     * @param index the page number. The first page is 1
     * @return the page size
     */
    public Rectangle getPageSize(int index) {
        return getPageSize(pageRefs.getPageNRelease(index));
    }

    /**
     * Gets the page from a page dictionary
     * @param page the page dictionary
     * @return the page
     */
    public Rectangle getPageSize(PdfDictionary page) {
        PdfArray mediaBox = (PdfArray)getPdfObject(page.get(PdfName.MEDIABOX));
        return getNormalizedRectangle(mediaBox);
    }

    /** Gets the crop box without taking rotation into account. This
     * is the value of the /CropBox key. The crop box is the part
     * of the document to be displayed or printed. It usually is the same
     * as the media box but may be smaller. If the page doesn't have a crop
     * box the page size will be returned.
     * @param index the page number. The first page is 1
     * @return the crop box
     */
    public Rectangle getCropBox(int index) {
        PdfDictionary page = pageRefs.getPageNRelease(index);
        PdfArray cropBox = (PdfArray)getPdfObjectRelease(page.get(PdfName.CROPBOX));
        if (cropBox == null)
            return getPageSize(page);
        return getNormalizedRectangle(cropBox);
    }

    /** Gets the box size. Allowed names are: "crop", "trim", "art", "bleed" and "media".
     * @param index the page number. The first page is 1
     * @param boxName the box name
     * @return the box rectangle or null
     */
    public Rectangle getBoxSize(int index, String boxName) {
        PdfDictionary page = pageRefs.getPageNRelease(index);
        PdfArray box = null;
        if (boxName.equals("trim"))
            box = (PdfArray)getPdfObjectRelease(page.get(PdfName.TRIMBOX));
        else if (boxName.equals("art"))
            box = (PdfArray)getPdfObjectRelease(page.get(PdfName.ARTBOX));
        else if (boxName.equals("bleed"))
            box = (PdfArray)getPdfObjectRelease(page.get(PdfName.BLEEDBOX));
        else if (boxName.equals("crop"))
            box = (PdfArray)getPdfObjectRelease(page.get(PdfName.CROPBOX));
        else if (boxName.equals("media"))
            box = (PdfArray)getPdfObjectRelease(page.get(PdfName.MEDIABOX));
        if (box == null)
            return null;
        return getNormalizedRectangle(box);
    }

    /** Returns the content of the document information dictionary as a <CODE>HashMap</CODE>
     * of <CODE>String</CODE>.
     * @return content of the document information dictionary
     */
    public HashMap getInfo() {
        HashMap map = new HashMap();
        PdfDictionary info = (PdfDictionary)getPdfObject(trailer.get(PdfName.INFO));
        if (info == null)
            return map;
        for (Iterator it = info.getKeys().iterator(); it.hasNext();) {
            PdfName key = (PdfName)it.next();
            PdfObject obj = getPdfObject(info.get(key));
            if (obj == null)
                continue;
            String value = obj.toString();
            switch (obj.type()) {
                case PdfObject.STRING: {
                    value = ((PdfString)obj).toUnicodeString();
                    break;
                }
                case PdfObject.NAME: {
                    value = PdfName.decodeName(value);
                    break;
                }
            }
            map.put(PdfName.decodeName(key.toString()), value);
        }
        return map;
    }

    /** Normalizes a <CODE>Rectangle</CODE> so that llx and lly are smaller than urx and ury.
     * @param box the original rectangle
     * @return a normalized <CODE>Rectangle</CODE>
     */
    public static Rectangle getNormalizedRectangle(PdfArray box) {
        ArrayList rect = box.getArrayList();
        float llx = ((PdfNumber)rect.get(0)).floatValue();
        float lly = ((PdfNumber)rect.get(1)).floatValue();
        float urx = ((PdfNumber)rect.get(2)).floatValue();
        float ury = ((PdfNumber)rect.get(3)).floatValue();
        return new Rectangle(Math.min(llx, urx), Math.min(lly, ury),
        Math.max(llx, urx), Math.max(lly, ury));
    }

    protected void readPdf() throws IOException {
        try {
            fileLength = tokens.getFile().length();
            pdfVersion = tokens.checkPdfHeader();
            try {
                readXref();
            }
            catch (Exception e) {
                try {
                    rebuilt = true;
                    rebuildXref();
                    lastXref = -1;
                }
                catch (Exception ne) {
                    throw new IOException("Rebuild failed: " + ne.getMessage() + "; Original message: " + e.getMessage());
                }
            }
            try {
                readDocObj();
            }
            catch (Exception ne) {
                if (rebuilt)
                    throw new IOException(ne.getMessage());
                rebuilt = true;
                encrypted = false;
                rebuildXref();
                lastXref = -1;
                readDocObj();
            }

            strings.clear();
            readPages();
            eliminateSharedStreams();
            removeUnusedObjects();
        }
        finally {
            try {
                tokens.close();
            }
            catch (Exception e) {
                // empty on purpose
            }
        }
    }

    protected void readPdfPartial() throws IOException {
        try {
            fileLength = tokens.getFile().length();
            pdfVersion = tokens.checkPdfHeader();
            try {
                readXref();
            }
            catch (Exception e) {
                try {
                    rebuilt = true;
                    rebuildXref();
                    lastXref = -1;
                }
                catch (Exception ne) {
                    throw new IOException("Rebuild failed: " + ne.getMessage() + "; Original message: " + e.getMessage());
                }
            }
            readDocObjPartial();
            readPages();
        }
        catch (IOException e) {
            try{tokens.close();}catch(Exception ee){}
            throw e;
        }
    }

    private boolean equalsArray(byte ar1[], byte ar2[], int size) {
        for (int k = 0; k < size; ++k) {
            if (ar1[k] != ar2[k])
                return false;
        }
        return true;
    }

    /**
     * @throws IOException
     */
    private void readDecryptedDocObj() throws IOException {
        if (encrypted)
            return;
        PdfObject encDic = trailer.get(PdfName.ENCRYPT);
        if (encDic == null || encDic.toString().equals("null"))
            return;
        byte[] encryptionKey = null;    	
        encrypted = true;
        PdfDictionary enc = (PdfDictionary)getPdfObject(encDic);

        String s;
        PdfObject o;

        PdfArray documentIDs = (PdfArray)getPdfObject(trailer.get(PdfName.ID));
        byte documentID[] = null;
        if (documentIDs != null) {
            o = (PdfObject)documentIDs.getArrayList().get(0);
            strings.remove(o);
            s = o.toString();
            documentID = com.lowagie.text.DocWriter.getISOBytes(s);
            if (documentIDs.size() > 1)
                strings.remove(documentIDs.getArrayList().get(1));
        }

        byte uValue[] = null;
        byte oValue[] = null;
        int cryptoMode = PdfWriter.STANDARD_ENCRYPTION_40;
        int lengthValue = 0;  
        
        PdfObject filter = getPdfObjectRelease(enc.get(PdfName.FILTER));

        if (filter.equals(PdfName.STANDARD))
        {        	        
            s = enc.get(PdfName.U).toString();
            strings.remove(enc.get(PdfName.U));
            uValue = com.lowagie.text.DocWriter.getISOBytes(s);
            s = enc.get(PdfName.O).toString();
            strings.remove(enc.get(PdfName.O));
            oValue = com.lowagie.text.DocWriter.getISOBytes(s);

            o = enc.get(PdfName.R);
            if (!o.isNumber()) throw new IOException("Illegal R value.");
            rValue = ((PdfNumber)o).intValue();
            if (rValue != 2 && rValue != 3 && rValue != 4)
                throw new IOException("Unknown encryption type (" + rValue + ")");

            o = enc.get(PdfName.P);
            if (!o.isNumber()) throw new IOException("Illegal P value.");
            pValue = ((PdfNumber)o).intValue();
   
            if ( rValue == 3 ){
                o = enc.get(PdfName.LENGTH);
                if (!o.isNumber())
                    throw new IOException("Illegal Length value.");
                lengthValue = ( (PdfNumber) o).intValue();
                if (lengthValue > 128 || lengthValue < 40 || lengthValue % 8 != 0)
                    throw new IOException("Illegal Length value.");
                cryptoMode = PdfWriter.STANDARD_ENCRYPTION_128;
            }  else if (rValue == 4) {
                PdfDictionary dic = (PdfDictionary)enc.get(PdfName.CF);
                if (dic == null)
                    throw new IOException("/CF not found (encryption)");
                dic = (PdfDictionary)dic.get(PdfName.STDCF);
                if (dic == null)
                    throw new IOException("/StdCF not found (encryption)");
                if (PdfName.V2.equals(dic.get(PdfName.CFM)))
                    cryptoMode = PdfWriter.STANDARD_ENCRYPTION_128;
                else if (PdfName.AESV2.equals(dic.get(PdfName.CFM)))
                    cryptoMode = PdfWriter.ENCRYPTION_AES_128;
                else
                    throw new IOException("No compatible encryption found");
                PdfObject em = enc.get(PdfName.ENCRYPTMETADATA);
                if (em != null && em.toString().equals("false"))
                    cryptoMode |= PdfWriter.DO_NOT_ENCRYPT_METADATA;
            } else {
                cryptoMode = PdfWriter.STANDARD_ENCRYPTION_40;
            }
        } else if (filter.equals(PdfName.PUBSEC)) {
            boolean foundRecipient = false;
            byte[] envelopedData = null;
            PdfArray recipients = null;

            o = enc.get(PdfName.V);
            if (!o.isNumber()) throw new IOException("Illegal V value.");
            int vValue = ((PdfNumber)o).intValue();
            if (vValue != 1 && vValue != 2 && vValue != 4)
                throw new IOException("Unknown encryption type V = " + rValue);

            if ( vValue == 2 ){
                o = enc.get(PdfName.LENGTH);
                if (!o.isNumber())
                    throw new IOException("Illegal Length value.");
                lengthValue = ( (PdfNumber) o).intValue();
                if (lengthValue > 128 || lengthValue < 40 || lengthValue % 8 != 0)
                    throw new IOException("Illegal Length value.");
                cryptoMode = PdfWriter.STANDARD_ENCRYPTION_128;                
                recipients = (PdfArray)enc.get(PdfName.RECIPIENTS);                                
            } else if (vValue == 4) {
                PdfDictionary dic = (PdfDictionary)enc.get(PdfName.CF);
                if (dic == null)
                    throw new IOException("/CF not found (encryption)");
                dic = (PdfDictionary)dic.get(PdfName.DEFAULTCRYPTFILER);
                if (dic == null)
                    throw new IOException("/DefaultCryptFilter not found (encryption)");
                if (PdfName.V2.equals(dic.get(PdfName.CFM)))
                {
                    cryptoMode = PdfWriter.STANDARD_ENCRYPTION_128;
                    lengthValue = 128;
                }
                else if (PdfName.AESV2.equals(dic.get(PdfName.CFM)))
                {
                    cryptoMode = PdfWriter.ENCRYPTION_AES_128;
                    lengthValue = 128;
                }
                else
                    throw new IOException("No compatible encryption found");
                PdfObject em = dic.get(PdfName.ENCRYPTMETADATA);
                if (em != null && em.toString().equals("false"))
                    cryptoMode |= PdfWriter.DO_NOT_ENCRYPT_METADATA;