/**
* Construct a client-side proxy that implements the named protocol, talking to a server at the
* named address.
*
* @param protocol protocol
* @param clientVersion client's version
* @param addr server address
* @param ticket security ticket
* @param conf configuration
* @param factory socket factory
* @param rpcTimeout max time for each rpc; 0 means no timeout
* @return the proxy
* @throws IOException if any error occurs
*/
@SuppressWarnings("unchecked")
public static <T extends VersionedProtocol> ProtocolProxy<T> getProtocolProxy(
Class<T> protocol,
long clientVersion,
InetSocketAddress addr,
UserGroupInformation ticket,
Configuration conf,
SocketFactory factory,
int rpcTimeout)
throws IOException {
T proxy =
(T)
Proxy.newProxyInstance(
protocol.getClassLoader(),
new Class[] {protocol},
new Invoker(addr, ticket, conf, factory, rpcTimeout, protocol));
String protocolName = protocol.getName();
try {
ProtocolSignature serverInfo =
proxy.getProtocolSignature(
protocolName, clientVersion, ProtocolSignature.getFingerprint(protocol.getMethods()));
return new ProtocolProxy<T>(protocol, proxy, serverInfo.getMethods());
} catch (RemoteException re) {
IOException ioe = re.unwrapRemoteException(IOException.class);
if (ioe.getMessage()
.startsWith(IOException.class.getName() + ": " + NoSuchMethodException.class.getName())) {
// Method getProtocolSignature not supported
long serverVersion = proxy.getProtocolVersion(protocol.getName(), clientVersion);
if (serverVersion == clientVersion) {
return new ProtocolProxy<T>(protocol, proxy, null);
}
throw new VersionMismatch(protocolName, clientVersion, serverVersion, proxy);
}
throw re;
}
}
public Invocation(Method method, Object[] parameters) {
this.methodName = method.getName();
this.parameterClasses = method.getParameterTypes();
this.parameters = parameters;
rpcVersion = writableRpcVersion;
if (method.getDeclaringClass().equals(VersionedProtocol.class)) {
// VersionedProtocol is exempted from version check.
clientVersion = 0;
clientMethodsHash = 0;
} else {
this.clientVersion = RPC.getProtocolVersion(method.getDeclaringClass());
this.clientMethodsHash =
ProtocolSignature.getFingerprint(method.getDeclaringClass().getMethods());
}
this.declaringClassProtocolName = RPC.getProtocolName(method.getDeclaringClass());
}