Java 类org.apache.hadoop.hdfs.util.ByteBufferOutputStream 实例源码

/**
 * Ensures that either the UTF-8 text has been set directly or by indirectly converting the Map contents to JSON.
 */
private void ensureTextSet() {
    if (_text.limit() == 0) {
        checkState(_map != null, "Neither JSON text nor map has been set");
        _text.clear();
        // First try reading the JSON directly into be buffer.
        try {
            JsonHelper.writeJson(new ByteBufferOutputStream(_text), _map);
            // Set the limit and move the position back to zero.
            _text.flip();
        } catch (Exception e) {
            if (Iterables.tryFind(Throwables.getCausalChain(e), Predicates.instanceOf(BufferOverflowException.class)).isPresent()) {
                // Buffer was insufficient.  Allocate a new array and read the bytes into it.
                byte[] utf8 = JsonHelper.asUtf8Bytes(_map);
                _text = ByteBuffer.wrap(utf8);
            } else {
                throw Throwables.propagate(e);
            }
        }
    }
}