/**
* 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.camel.dataformat.avro;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericContainer;
import org.apache.avro.generic.GenericRecord;
import org.apache.avro.io.DatumReader;
import org.apache.avro.io.DatumWriter;
import org.apache.avro.io.Decoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.io.Encoder;
import org.apache.avro.io.EncoderFactory;
import org.apache.avro.specific.SpecificDatumReader;
import org.apache.avro.specific.SpecificDatumWriter;
import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.CamelException;
import org.apache.camel.Exchange;
import org.apache.camel.spi.DataFormat;
import org.apache.camel.support.ServiceSupport;
import org.apache.camel.util.ObjectHelper;
public class AvroDataFormat extends ServiceSupport implements DataFormat, CamelContextAware {
private static final String GENERIC_CONTAINER_CLASSNAME = GenericContainer.class.getName();
private CamelContext camelContext;
private Object schema;
private transient Schema actualSchema;
private String instanceClassName;
public AvroDataFormat() {
}
public AvroDataFormat(Schema schema) {
this.schema = schema;
}
public CamelContext getCamelContext() {
return camelContext;
}
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
@Override
protected void doStart() throws Exception {
if (schema != null) {
if (schema instanceof Schema) {
actualSchema = (Schema) schema;
} else {
actualSchema = loadSchema(schema.getClass().getName());
}
} else if (instanceClassName != null) {
actualSchema = loadSchema(instanceClassName);
}
}
@Override
protected void doStop() throws Exception {
// noop
}
// the getter/setter for Schema is Object type in the API
public Object getSchema() {
return actualSchema != null ? actualSchema : schema;
}
public void setSchema(Object schema) {
this.schema = schema;
}
public String getInstanceClassName() {
return instanceClassName;
}
public void setInstanceClass(String className) throws Exception {
instanceClassName = className;
}
protected Schema loadSchema(String className) throws CamelException, ClassNotFoundException {
// must use same class loading procedure to ensure working in OSGi
Class<?> instanceClass = camelContext.getClassResolver().resolveMandatoryClass(className);
Class<?> genericContainer = camelContext.getClassResolver().resolveMandatoryClass(GENERIC_CONTAINER_CLASSNAME);
if (genericContainer.isAssignableFrom(instanceClass)) {
try {
Method method = instanceClass.getMethod("getSchema", new Class[0]);
return (Schema) method.invoke(camelContext.getInjector().newInstance(instanceClass));
} catch (Exception ex) {
throw new CamelException("Error calling getSchema on " + instanceClass, ex);
}
} else {
throw new CamelException("Class " + instanceClass + " must be instanceof " + GENERIC_CONTAINER_CLASSNAME);
}
}
public void marshal(Exchange exchange, Object graph, OutputStream outputStream) throws Exception {
// the schema should be from the graph class name
Schema useSchema = actualSchema != null ? actualSchema : loadSchema(graph.getClass().getName());
DatumWriter<Object> datum = new SpecificDatumWriter<Object>(useSchema);
Encoder encoder = EncoderFactory.get().binaryEncoder(outputStream, null);
datum.write(graph, encoder);
encoder.flush();
}
public Object unmarshal(Exchange exchange, InputStream inputStream) throws Exception {
ObjectHelper.notNull(actualSchema, "schema", this);
DatumReader<GenericRecord> reader = new SpecificDatumReader<GenericRecord>(actualSchema);
Decoder decoder = DecoderFactory.get().binaryDecoder(inputStream, null);
Object result = reader.read(null, decoder);
return result;
}
}