pdfencryptor.java

处理PDF

    
    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param type the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128.
     * Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @param newInfo an optional <CODE>String</CODE> map to add or change
     * the info dictionary. Entries with <CODE>null</CODE>
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     */
    public static void encrypt(PdfReader reader, OutputStream os, int type, String userPassword, String ownerPassword, int permissions, HashMap newInfo) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(type, userPassword, ownerPassword, permissions);
        stamper.setMoreInfo(newInfo);
        stamper.close();
    }
    
    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param type the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128.
     * Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     */
    public static void encrypt(PdfReader reader, OutputStream os, int type, String userPassword, String ownerPassword, int permissions) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(type, userPassword, ownerPassword, permissions);
        stamper.close();
    }
    
    /**
     * Give you a verbose analysis of the permissions.
     * @param permissions the permissions value of a PDF file
     * @return a String that explains the meaning of the permissions value
     */
    public static String getPermissionsVerbose(int permissions) {
    	StringBuffer buf = new StringBuffer("Allowed:");
    	if ((PdfWriter.ALLOW_PRINTING & permissions) == PdfWriter.ALLOW_PRINTING) buf.append(" Printing");
        if ((PdfWriter.ALLOW_MODIFY_CONTENTS & permissions) == PdfWriter.ALLOW_MODIFY_CONTENTS) buf.append(" Modify contents");
        if ((PdfWriter.ALLOW_COPY & permissions) == PdfWriter.ALLOW_COPY) buf.append(" Copy");
        if ((PdfWriter.ALLOW_MODIFY_ANNOTATIONS & permissions) == PdfWriter.ALLOW_MODIFY_ANNOTATIONS) buf.append(" Modify annotations");
        if ((PdfWriter.ALLOW_FILL_IN & permissions) == PdfWriter.ALLOW_FILL_IN) buf.append(" Fill in");
        if ((PdfWriter.ALLOW_SCREENREADERS & permissions) == PdfWriter.ALLOW_SCREENREADERS) buf.append(" Screen readers");
        if ((PdfWriter.ALLOW_ASSEMBLY & permissions) == PdfWriter.ALLOW_ASSEMBLY) buf.append(" Assembly");
        if ((PdfWriter.ALLOW_DEGRADED_PRINTING & permissions) == PdfWriter.ALLOW_DEGRADED_PRINTING) buf.append(" Degraded printing");
        return buf.toString();
    }
    
    /**
     * Tells you if printing is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if printing is allowed
     *
     * @since 2.0.7
     */
    public static boolean isPrintingAllowed(int permissions) {
        return (PdfWriter.ALLOW_PRINTING & permissions) == PdfWriter.ALLOW_PRINTING;
    }
    
    /**
     * Tells you if modifying content is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if modifying content is allowed
     *
     * @since 2.0.7
     */
    public static boolean isModifyContentsAllowed(int permissions) {
        return (PdfWriter.ALLOW_MODIFY_CONTENTS & permissions) == PdfWriter.ALLOW_MODIFY_CONTENTS;
    } 
    
    /**
     * Tells you if copying is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if copying is allowed
     *
     * @since 2.0.7
     */
    public static boolean isCopyAllowed(int permissions) {
        return (PdfWriter.ALLOW_COPY & permissions) == PdfWriter.ALLOW_COPY;
    }
    
    /**
     * Tells you if modifying annotations is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if modifying annotations is allowed
     *
     * @since 2.0.7
     */
    public static boolean isModifyAnnotationsAllowed(int permissions) {
        return (PdfWriter.ALLOW_MODIFY_ANNOTATIONS & permissions) == PdfWriter.ALLOW_MODIFY_ANNOTATIONS;
    }
    
    /**
     * Tells you if filling in fields is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if filling in fields is allowed
     *
     * @since 2.0.7
     */
    public static boolean isFillInAllowed(int permissions) {
        return (PdfWriter.ALLOW_FILL_IN & permissions) == PdfWriter.ALLOW_FILL_IN;
    }
    
    /**
     * Tells you if repurposing for screenreaders is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if repurposing for screenreaders is allowed
     *
     * @since 2.0.7
     */
    public static boolean isScreenReadersAllowed(int permissions) {
        return (PdfWriter.ALLOW_SCREENREADERS & permissions) == PdfWriter.ALLOW_SCREENREADERS;
    }
    
    /**
     * Tells you if document assembly is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if document assembly is allowed
     *
     * @since 2.0.7
     */
    public static boolean isAssemblyAllowed(int permissions) {
        return (PdfWriter.ALLOW_ASSEMBLY & permissions) == PdfWriter.ALLOW_ASSEMBLY;
    }
    
    /**
     * Tells you if degraded printing is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if degraded printing is allowed
     *
     * @since 2.0.7
     */
    public static boolean isDegradedPrintingAllowed(int permissions) {
        return (PdfWriter.ALLOW_DEGRADED_PRINTING & permissions) == PdfWriter.ALLOW_DEGRADED_PRINTING;
    }
}