protected void encodeResponse(Channel channel, ChannelBuffer buffer, Response res)
throws IOException {
try {
Serialization serialization = getSerialization(channel);
// header.
byte[] header = new byte[HEADER_LENGTH];
// set magic number.
Bytes.short2bytes(MAGIC, header);
// set request and serialization flag.
header[2] = serialization.getContentTypeId();
if (res.isHeartbeat()) header[2] |= FLAG_EVENT;
// set response status.
byte status = res.getStatus();
header[3] = status;
// set request id.
Bytes.long2bytes(res.getId(), header, 4);
int savedWriteIndex = buffer.writerIndex();
buffer.writerIndex(savedWriteIndex + HEADER_LENGTH);
ChannelBufferOutputStream bos = new ChannelBufferOutputStream(buffer);
ObjectOutput out = serialization.serialize(channel.getUrl(), bos);
try {
// encode response data or error message.
if (status == Response.OK) {
if (res.isHeartbeat()) {
encodeHeartbeatData(channel, out, res.getResult());
} else {
encodeResponseData(channel, out, res.getResult());
}
} else out.writeUTF(res.getErrorMessage());
out.flushBuffer();
} finally {
// modified by lishen
if (out instanceof Cleanable) {
((Cleanable) out).cleanup();
}
}
bos.flush();
bos.close();
int len = bos.writtenBytes();
checkPayload(channel, len);
Bytes.int2bytes(len, header, 12);
// write
buffer.writerIndex(savedWriteIndex);
buffer.writeBytes(header); // write header.
buffer.writerIndex(savedWriteIndex + HEADER_LENGTH + len);
} catch (Throwable t) {
// 发送失败信息给Consumer，否则Consumer只能等超时了
if (!res.isEvent() && res.getStatus() != Response.BAD_RESPONSE) {
try {
// FIXME 在Codec中打印出错日志？在IoHanndler的caught中统一处理？
logger.warn(
"Fail to encode response: "
+ res
+ ", send bad_response info instead, cause: "
+ t.getMessage(),
t);
Response r = new Response(res.getId(), res.getVersion());
r.setStatus(Response.BAD_RESPONSE);
r.setErrorMessage(
"Failed to send response: " + res + ", cause: " + StringUtils.toString(t));
channel.send(r);
return;
} catch (RemotingException e) {
logger.warn(
"Failed to send bad_response info back: " + res + ", cause: " + e.getMessage(), e);
}
}
// 重新抛出收到的异常
if (t instanceof IOException) {
throw (IOException) t;
} else if (t instanceof RuntimeException) {
throw (RuntimeException) t;
} else if (t instanceof Error) {
throw (Error) t;
} else {
throw new RuntimeException(t.getMessage(), t);
}
}
}
