org.lilyproject.repository.avro.LilySpecificResponder.java Source code

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Here is the source code for org.lilyproject.repository.avro.LilySpecificResponder.java

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/*
 * Copyright 2010 Outerthought bvba
 *
 * Licensed 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.lilyproject.repository.avro;

import org.apache.avro.AvroRuntimeException;
import org.apache.avro.Protocol;
import org.apache.avro.Schema;
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.Responder;
import org.apache.avro.specific.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

// This code is copied from the Avro codebase with some customisations to handle
// remote propagation of runtime exceptions

public class LilySpecificResponder extends Responder {
    private Object impl;
    private SpecificData data;
    private AvroConverter converter;
    private Log log = LogFactory.getLog(getClass());

    public LilySpecificResponder(Class iface, Object impl, AvroConverter converter) {
        this(SpecificData.get().getProtocol(iface), impl);
        this.converter = converter;
    }

    public LilySpecificResponder(Protocol protocol, Object impl) {
        this(protocol, impl, SpecificData.get());
    }

    protected LilySpecificResponder(Protocol protocol, Object impl, SpecificData data) {
        super(protocol);
        this.impl = impl;
        this.data = data;
    }

    protected DatumWriter<Object> getDatumWriter(Schema schema) {
        return new SpecificDatumWriter<Object>(schema);
    }

    protected DatumReader<Object> getDatumReader(Schema schema) {
        return new SpecificDatumReader<Object>(schema);
    }

    @Override
    public Object readRequest(Schema schema, Decoder in) throws IOException {
        Object[] args = new Object[schema.getFields().size()];
        int i = 0;
        for (Schema.Field param : schema.getFields())
            args[i++] = getDatumReader(param.schema()).read(null, in);
        return args;
    }

    @Override
    public void writeResponse(Schema schema, Object response, Encoder out) throws IOException {
        getDatumWriter(schema).write(response, out);
    }

    @Override
    public void writeError(Schema schema, Object error, Encoder out) throws IOException {
        if (!(error instanceof SpecificRecord)) {
            String message = "Avro responder is being asked to write an exception which is not a specific Avro type. "
                    + "A likely cause of this message is that there is a method in lily.avpr which is missing a "
                    + "declaration of AvroGenericException. " + "ClassName: " + error.getClass().getName()
                    + ", toString: " + error.toString();
            if (error instanceof Throwable) {
                log.error(message, (Throwable) error);
            } else {
                log.error(message);
            }
        }

        getDatumWriter(schema).write(error, out);
    }

    @Override
    public Object respond(Protocol.Message message, Object request) throws Exception {
        Class[] paramTypes = new Class[message.getRequest().getFields().size()];
        int i = 0;
        try {
            for (Schema.Field param : message.getRequest().getFields())
                paramTypes[i++] = data.getClass(param.schema());
            Method method = impl.getClass().getMethod(message.getName(), paramTypes);
            return method.invoke(impl, (Object[]) request);
        } catch (InvocationTargetException e) {
            if (e.getTargetException() instanceof SpecificRecord) {
                throw (Exception) e.getTargetException();
            } else {
                throw converter.convertOtherException(e.getTargetException());
            }
        } catch (NoSuchMethodException e) {
            throw new AvroRuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new AvroRuntimeException(e);
        }
    }
}