/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.avro.ipc.specific;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Type;
import java.util.Arrays;
import org.apache.avro.AvroRemoteException;
import org.apache.avro.Protocol;
import org.apache.avro.Schema;
import org.apache.avro.AvroRuntimeException;
import org.apache.avro.io.DatumReader;
import org.apache.avro.io.DatumWriter;
import org.apache.avro.io.Decoder;
import org.apache.avro.io.Encoder;
import org.apache.avro.ipc.Transceiver;
import org.apache.avro.ipc.Requestor;
import org.apache.avro.ipc.Callback;
import org.apache.avro.specific.SpecificData;
import org.apache.avro.specific.SpecificDatumReader;
import org.apache.avro.specific.SpecificDatumWriter;
/** {@link org.apache.avro.ipc.Requestor Requestor} for generated interfaces. */
public class SpecificRequestor extends Requestor implements InvocationHandler {
public SpecificRequestor(Class<?> iface, Transceiver transceiver)
throws IOException {
this(SpecificData.get().getProtocol(iface), transceiver);
}
protected SpecificRequestor(Protocol protocol, Transceiver transceiver)
throws IOException {
super(protocol, transceiver);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
try {
// Check if this is a callback-based RPC:
Type[] parameterTypes = method.getParameterTypes();
if ((parameterTypes.length > 0) &&
(parameterTypes[parameterTypes.length - 1] instanceof Class) &&
Callback.class.isAssignableFrom(((Class<?>)parameterTypes[parameterTypes.length - 1]))) {
// Extract the Callback from the end of of the argument list
Object[] finalArgs = Arrays.copyOf(args, args.length - 1);
Callback<?> callback = (Callback<?>)args[args.length - 1];
request(method.getName(), finalArgs, callback);
return null;
}
else {
return request(method.getName(), args);
}
} catch (Exception e) {
// Check if this is a declared Exception:
for (Class<?> exceptionClass : method.getExceptionTypes()) {
if (exceptionClass.isAssignableFrom(e.getClass())) {
throw e;
}
}
// Next, check for RuntimeExceptions:
if (e instanceof RuntimeException) {
throw e;
}
// Not an expected Exception, so wrap it in AvroRemoteException:
throw new AvroRemoteException(e);
}
}
protected DatumWriter<Object> getDatumWriter(Schema schema) {
return new SpecificDatumWriter<Object>(schema);
}
@Deprecated // for compatibility in 1.5
protected DatumReader<Object> getDatumReader(Schema schema) {
return getDatumReader(schema, schema);
}
protected DatumReader<Object> getDatumReader(Schema writer, Schema reader) {
return new SpecificDatumReader<Object>(writer, reader);
}
@Override
public void writeRequest(Schema schema, Object request, Encoder out)
throws IOException {
Object[] args = (Object[])request;
int i = 0;
for (Schema.Field param : schema.getFields())
getDatumWriter(param.schema()).write(args[i++], out);
}
@Override
public Object readResponse(Schema writer, Schema reader, Decoder in)
throws IOException {
return getDatumReader(writer, reader).read(null, in);
}
@Override
public Exception readError(Schema writer, Schema reader, Decoder in)
throws IOException {
Object value = getDatumReader(writer, reader).read(null, in);
if (value instanceof Exception)
return (Exception)value;
return new AvroRuntimeException(value.toString());
}
/** Create a proxy instance whose methods invoke RPCs. */
public static <T> T getClient(Class<T> iface, Transceiver transciever)
throws IOException {
return getClient(iface, transciever, SpecificData.get());
}
/** Create a proxy instance whose methods invoke RPCs. */
@SuppressWarnings("unchecked")
public static <T> T getClient(Class<T> iface, Transceiver transciever,
SpecificData specificData)
throws IOException {
Protocol protocol = specificData.getProtocol(iface);
return (T)Proxy.newProxyInstance(iface.getClassLoader(),
new Class[] { iface },
new SpecificRequestor(protocol, transciever));
}
/** Create a proxy instance whose methods invoke RPCs. */
@SuppressWarnings("unchecked")
public static <T> T getClient(Class<T> iface, SpecificRequestor requestor)
throws IOException {
return (T)Proxy.newProxyInstance(iface.getClassLoader(),
new Class[] { iface }, requestor);
}
/** Return the remote protocol for a proxy. */
public static Protocol getRemote(Object proxy) throws IOException {
return ((Requestor)Proxy.getInvocationHandler(proxy)).getRemote();
}
}