/**
* Read the JabRef signature, if any, and find what version number is given. This method advances
* the file reader only as far as the end of the first line of the JabRef signature, or up until
* the point where the read characters don't match the signature. This should ensure that the
* parser can continue from that spot without resetting the reader, without the risk of losing
* important contents.
*
* @return The version number, or null if not found.
* @throws IOException
*/
private String readJabRefVersionNumber() throws IOException {
StringBuffer headerText = new StringBuffer();
boolean keepon = true;
int piv = 0;
int c;
// We start by reading the standard part of the signature, which precedes
// the version number:
// This file was created with JabRef X.y.
while (keepon) {
c = peek();
headerText.append((char) c);
if ((piv == 0) && (Character.isWhitespace((char) c) || (c == '%'))) read();
else if (c == GUIGlobals.SIGNATURE.charAt(piv)) {
piv++;
read();
} else {
keepon = false;
return null;
}
// Check if we've reached the end of the signature's standard part:
if (piv == GUIGlobals.SIGNATURE.length()) {
keepon = false;
// Found the standard part. Now read the version number:
StringBuilder sb = new StringBuilder();
while (((c = read()) != '\n') && (c != -1)) sb.append((char) c);
String versionNum = sb.toString().trim();
// See if it fits the X.y. pattern:
if (Pattern.compile("[1-9]+\\.[1-9A-Za-z ]+\\.").matcher(versionNum).matches()) {
// It matched. Remove the last period and return:
return versionNum.substring(0, versionNum.length() - 1);
}
}
}
return null;
}
