/**
* Parse the value of an <code>Accept-Language</code> header, and add the corresponding Locales to
* the current request.
*
* @param value The value of the <code>Accept-Language</code> header.
*/
private void parseAcceptLanguage(String value) {
// Store the accumulated languages that have been requested in
// a local collection, sorted by the quality value (so we can
// add Locales in descending order). The values will be ArrayLists
// containing the corresponding Locales to be added
TreeMap locales = new TreeMap();
// Preprocess the value to remove all whitespace
int white = value.indexOf(' ');
if (white < 0) white = value.indexOf('\t');
if (white >= 0) {
StringBuffer sb = new StringBuffer();
int len = value.length();
for (int i = 0; i < len; i++) {
char ch = value.charAt(i);
if ((ch != ' ') && (ch != '\t')) sb.append(ch);
}
value = sb.toString();
}
// Process each comma-delimited language specification
parser.setString(value); // ASSERT: parser is available to us
int length = parser.getLength();
while (true) {
// Extract the next comma-delimited entry
int start = parser.getIndex();
if (start >= length) break;
int end = parser.findChar(',');
String entry = parser.extract(start, end).trim();
parser.advance(); // For the following entry
// Extract the quality factor for this entry
double quality = 1.0;
int semi = entry.indexOf(";q=");
if (semi >= 0) {
try {
quality = Double.parseDouble(entry.substring(semi + 3));
} catch (NumberFormatException e) {
quality = 0.0;
}
entry = entry.substring(0, semi);
}
// Skip entries we are not going to keep track of
if (quality < 0.00005) continue; // Zero (or effectively zero) quality factors
if ("*".equals(entry)) continue; // FIXME - "*" entries are not handled
// Extract the language and country for this entry
String language = null;
String country = null;
String variant = null;
int dash = entry.indexOf('-');
if (dash < 0) {
language = entry;
country = "";
variant = "";
} else {
language = entry.substring(0, dash);
country = entry.substring(dash + 1);
int vDash = country.indexOf('-');
if (vDash > 0) {
String cTemp = country.substring(0, vDash);
variant = country.substring(vDash + 1);
country = cTemp;
} else {
variant = "";
}
}
// Add a new Locale to the list of Locales for this quality level
Locale locale = new Locale(language, country, variant);
Double key = new Double(-quality); // Reverse the order
ArrayList values = (ArrayList) locales.get(key);
if (values == null) {
values = new ArrayList();
locales.put(key, values);
}
values.add(locale);
}
// Process the quality values in highest->lowest order (due to
// negating the Double value when creating the key)
Iterator keys = locales.keySet().iterator();
while (keys.hasNext()) {
Double key = (Double) keys.next();
ArrayList list = (ArrayList) locales.get(key);
Iterator values = list.iterator();
while (values.hasNext()) {
Locale locale = (Locale) values.next();
if (debug >= 1) log(" Adding locale '" + locale + "'");
request.addLocale(locale);
}
}
}
