Reading Buffered-reader Character Wise?

what this code means?

public static String readBuffer(Reader reader, int limit) throws IOException {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < limit; i++) {
int c = reader.read();
if (c == -1) {
return ((sb.length() > 0) ? sb.toString() : null);

[Code] ....

I am particularly confused with the below lines -

if (((char) c == '
') || ((char) c == '
')) {
break;
}

This is how I am calling this code from my application -

BufferedReader bf = null;
StringBuffer stringBuff = new StringBuffer();
String ln = null;
while ((ln = readBuffer(bf, 2048)) != null) {
stringBuff.append(ln);
}