Java tutorial
/* * * This file is part of the iText (R) project. Copyright (c) 1998-2019 iText Group NV * Authors: Bruno Lowagie, Paulo Soares, et al. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License version 3 * as published by the Free Software Foundation with the addition of the * following permission added to Section 15 as permitted in Section 7(a): * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT * OF THIRD PARTY RIGHTS * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Affero General Public License for more details. * You should have received a copy of the GNU Affero General Public License * along with this program; if not, see http://www.gnu.org/licenses or write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA, 02110-1301 USA, or download the license from the following URL: * http://itextpdf.com/terms-of-use/ * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License. * * In accordance with Section 7(b) of the GNU Affero General Public License, * a covered work must retain the producer line in every PDF that is created * or manipulated using iText. * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial activities involving the iText software without * disclosing the source code of your own applications. * These activities include: offering paid services to customers as an ASP, * serving PDFs on the fly in a web application, shipping iText with a closed * source product. * * For more information, please contact iText Software Corp. at this * address: sales@itextpdf.com */ package com.itextpdf.text.pdf; import com.itextpdf.text.pdf.internal.PdfIsoKeys; import java.io.IOException; import java.io.OutputStream; /** * A <CODE>PdfString</CODE>-class is the PDF-equivalent of a * JAVA-<CODE>String</CODE>-object. * <P> * A string is a sequence of characters delimited by parenthesis. * If a string is too long to be conveniently placed on a single line, it may * be split across multiple lines by using the backslash character (\) at the * end of a line to indicate that the string continues on the following line. * Within a string, the backslash character is used as an escape to specify * unbalanced parenthesis, non-printing ASCII characters, and the backslash * character itself. Use of the \<I>ddd</I> escape sequence is the preferred * way to represent characters outside the printable ASCII character set.<BR> * This object is described in the 'Portable Document Format Reference Manual * version 1.7' section 3.2.3 (page 53-56). * * @see PdfObject * @see BadPdfFormatException */ public class PdfString extends PdfObject { // CLASS VARIABLES /** The value of this object. */ protected String value = NOTHING; protected String originalValue = null; /** The encoding. */ protected String encoding = TEXT_PDFDOCENCODING; protected int objNum = 0; protected int objGen = 0; protected boolean hexWriting = false; // CONSTRUCTORS /** * Constructs an empty <CODE>PdfString</CODE>-object. */ public PdfString() { super(STRING); } /** * Constructs a <CODE>PdfString</CODE>-object containing a string in the * standard encoding <CODE>TEXT_PDFDOCENCODING</CODE>. * * @param value the content of the string */ public PdfString(String value) { super(STRING); this.value = value; } /** * Constructs a <CODE>PdfString</CODE>-object containing a string in the * specified encoding. * * @param value the content of the string * @param encoding an encoding */ public PdfString(String value, String encoding) { super(STRING); this.value = value; this.encoding = encoding; } /** * Constructs a <CODE>PdfString</CODE>-object. * * @param bytes an array of <CODE>byte</CODE> */ public PdfString(byte[] bytes) { super(STRING); value = PdfEncodings.convertToString(bytes, null); encoding = NOTHING; } // methods overriding some methods in PdfObject /** * Writes the PDF representation of this <CODE>PdfString</CODE> as an array * of <CODE>byte</CODE> to the specified <CODE>OutputStream</CODE>. * * @param writer for backwards compatibility * @param os The <CODE>OutputStream</CODE> to write the bytes to. */ public void toPdf(PdfWriter writer, OutputStream os) throws IOException { PdfWriter.checkPdfIsoConformance(writer, PdfIsoKeys.PDFISOKEY_OBJECT, this); byte b[] = getBytes(); PdfEncryption crypto = null; if (writer != null) crypto = writer.getEncryption(); if (crypto != null && !crypto.isEmbeddedFilesOnly()) b = crypto.encryptByteArray(b); if (hexWriting) { ByteBuffer buf = new ByteBuffer(); buf.append('<'); int len = b.length; for (int k = 0; k < len; ++k) buf.appendHex(b[k]); buf.append('>'); os.write(buf.toByteArray()); } else os.write(StringUtils.escapeString(b)); } /** * Returns the <CODE>String</CODE> value of this <CODE>PdfString</CODE>-object. * * @return A <CODE>String</CODE> */ public String toString() { return value; } public byte[] getBytes() { if (bytes == null) { if (encoding != null && encoding.equals(TEXT_UNICODE) && PdfEncodings.isPdfDocEncoding(value)) bytes = PdfEncodings.convertToBytes(value, TEXT_PDFDOCENCODING); else bytes = PdfEncodings.convertToBytes(value, encoding); } return bytes; } // other methods /** * Returns the Unicode <CODE>String</CODE> value of this * <CODE>PdfString</CODE>-object. * * @return A <CODE>String</CODE> */ public String toUnicodeString() { if (encoding != null && encoding.length() != 0) return value; getBytes(); if (bytes.length >= 2 && bytes[0] == (byte) 254 && bytes[1] == (byte) 255) return PdfEncodings.convertToString(bytes, PdfObject.TEXT_UNICODE); else return PdfEncodings.convertToString(bytes, PdfObject.TEXT_PDFDOCENCODING); } /** * Gets the encoding of this string. * * @return a <CODE>String</CODE> */ public String getEncoding() { return encoding; } void setObjNum(int objNum, int objGen) { this.objNum = objNum; this.objGen = objGen; } /** * Decrypt an encrypted <CODE>PdfString</CODE> */ void decrypt(PdfReader reader) { PdfEncryption decrypt = reader.getDecrypt(); if (decrypt != null) { originalValue = value; decrypt.setHashKey(objNum, objGen); bytes = PdfEncodings.convertToBytes(value, null); bytes = decrypt.decryptByteArray(bytes); value = PdfEncodings.convertToString(bytes, null); } } public byte[] getOriginalBytes() { if (originalValue == null) return getBytes(); return PdfEncodings.convertToBytes(originalValue, null); } public PdfString setHexWriting(boolean hexWriting) { this.hexWriting = hexWriting; return this; } public boolean isHexWriting() { return hexWriting; } }