org.apache.avro.ipc.specific.SpecificRequestor Maven / Gradle / Ivy

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/**
 * 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 {
  SpecificData data;

  public SpecificRequestor(Class iface, Transceiver transceiver)
    throws IOException {
    this(iface, transceiver, new SpecificData(iface.getClassLoader()));
  }

  protected SpecificRequestor(Protocol protocol, Transceiver transceiver)
    throws IOException {
    this(protocol, transceiver, SpecificData.get());
  }

  public SpecificRequestor(Class iface, Transceiver transceiver,
                           SpecificData data)
    throws IOException {
    this(data.getProtocol(iface), transceiver, data);
  }

  public SpecificRequestor(Protocol protocol, Transceiver transceiver,
                           SpecificData data)
    throws IOException {
    super(protocol, transceiver);
    this.data = data;
  }

  public SpecificData getSpecificData() { return data; }

  @Override
  public Object invoke(Object proxy, Method method, Object[] args)
    throws Throwable {
    String name = method.getName();
    if (name.equals("hashCode")) {
      return hashCode();
    }
    else if (name.equals("equals")) {
      Object obj = args[0];
      return (proxy == obj) || (obj != null && Proxy.isProxyClass(obj.getClass())
                                && this.equals(Proxy.getInvocationHandler(obj)));
    }
    else if (name.equals("toString")) {
      String protocol = "unknown";
      String remote = "unknown";
      Class[] interfaces = proxy.getClass().getInterfaces();
      if (interfaces.length > 0) {
        try {
          protocol = Class.forName(interfaces[0].getName()).getSimpleName();
        } catch (ClassNotFoundException e) {
        }

        InvocationHandler handler = Proxy.getInvocationHandler(proxy);
        if (handler instanceof Requestor) {
          try {
            remote = ((Requestor) handler).getTransceiver().getRemoteName();
          } catch (IOException e) {
          }
        }
      }
      return "Proxy[" + protocol + "," + remote + "]";
    }
    else {
      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