PdfString-class is the PDF-equivalent of a JAVA-String-object.
*
* 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 \ddd escape sequence is the preferred way to represent characters
* outside the printable ASCII character set.
* This object is described in the 'Portable Document Format Reference Manual version 1.3'
* section 4.4 (page 37-39).
*
* @see PdfObject
* @see BadPdfFormatException
*/
public class PdfString extends PdfObject {
// membervariables
/** 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 PdfString-object.
*/
public PdfString() {
super(STRING);
}
/**
* Constructs a PdfString-object.
*
* @param value the content of the string
*/
public PdfString(String value) {
super(STRING);
this.value = value;
}
/**
* Constructs a PdfString-object.
*
* @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 PdfString-object.
*
* @param bytes an array of byte
*/
public PdfString(byte[] bytes) {
super(STRING);
value = PdfEncodings.convertToString(bytes, null);
encoding = NOTHING;
}
// methods overriding some methods in PdfObject
/**
* Returns the PDF representation of this PdfString.
*
* @return an array of bytes
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
byte b[] = getBytes();
PdfEncryption crypto = null;
if (writer != null)
crypto = writer.getEncryption();
if (crypto != null) {
b = (byte[])bytes.clone();
crypto.prepareKey();
crypto.encryptRC4(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(PdfContentByte.escapeString(b));
}
/**
* Returns the String value of the PdfString-object.
*
* @return a String
*/
public String toString() {
return value;
}
// other methods
/**
* Gets the encoding of this string.
*
* @return a String
*/
public String getEncoding() {
return encoding;
}
public String toUnicodeString() {
if (encoding != null && encoding.length() != 0)
return value;
getBytes();
if (bytes.length >= 2 && bytes[0] == (byte)254 && bytes[1] == (byte)255) {
// ssteward
// pdftk-0.94: trim off these signature bytes (problem reading bookmarks);
// pdftk-1.00: still an issue; problem reading EmbeddedFiles name tree keys,
// see PdfNameTree::iterateItems(); resulted in an extra null char at end of string
byte b_copy[]= new byte[bytes.length- 2];
System.arraycopy( bytes, 2, b_copy, 0, b_copy.length );
//return PdfEncodings.convertToString(bytes, PdfObject.TEXT_UNICODE);
return PdfEncodings.convertToString(b_copy, PdfObject.TEXT_UNICODE);
}
else
return PdfEncodings.convertToString(bytes, PdfObject.TEXT_PDFDOCENCODING);
}
void setObjNum(int objNum, int objGen) {
this.objNum = objNum;
this.objGen = objGen;
}
void decrypt(PdfReader reader) {
PdfEncryption decrypt = reader.getDecrypt();
if (decrypt != null) {
originalValue = value;
decrypt.setHashKey(objNum, objGen);
decrypt.prepareKey();
bytes = PdfEncodings.convertToBytes(value, null);
decrypt.encryptRC4(bytes);
value = PdfEncodings.convertToString(bytes, null);
}
}
public byte[] getBytes() {
if (bytes == null) {
/* ssteward, pdftk 1.0: I really needed the PdfString to output TEXT_UNICODE
when I asked it to; this had to do with EmbeddedFiles name tree names on
Acrobat 5--it wouldn't take any other encoding; see PdfNameTree.java for
related changes
if (encoding != null && encoding.equals(TEXT_UNICODE) && PdfEncodings.isPdfDocEncoding(value))
bytes = PdfEncodings.convertToBytes(value, TEXT_PDFDOCENCODING);
else
*/
bytes = PdfEncodings.convertToBytes(value, encoding);
}
return bytes;
}
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;
}
// ssteward; this.encoding not reliable?
public boolean isUnicode() {
getBytes();
return( bytes.length >= 2 && bytes[0] == (byte)254 && bytes[1] == (byte)255 );
}
}