in src/main/java/org/apache/commons/io/input/SequenceReader.java [116:139]
public int read(final char[] cbuf, int off, int len) throws IOException {
Objects.requireNonNull(cbuf, "cbuf");
if (len < 0 || off < 0 || off + len > cbuf.length) {
throw new IndexOutOfBoundsException("Array Size=" + cbuf.length + ", offset=" + off + ", length=" + len);
}
int count = 0;
while (reader != null) {
final int readLen = reader.read(cbuf, off, len);
if (readLen == EOF) {
nextReader();
} else {
count += readLen;
off += readLen;
len -= readLen;
if (len <= 0) {
break;
}
}
}
if (count > 0) {
return count;
}
return EOF;
}