/*
* 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.samza.serializers.model;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.samza.Partition;
import org.apache.samza.config.Config;
import org.apache.samza.config.MapConfig;
import org.apache.samza.container.TaskName;
import org.apache.samza.job.model.ContainerModel;
import org.apache.samza.job.model.JobModel;
import org.apache.samza.job.model.TaskModel;
import org.apache.samza.system.SystemStreamPartition;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.ObjectCodec;
import org.codehaus.jackson.Version;
import org.codehaus.jackson.map.DeserializationContext;
import org.codehaus.jackson.map.JsonDeserializer;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.MapperConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.PropertyNamingStrategy;
import org.codehaus.jackson.map.SerializerProvider;
import org.codehaus.jackson.map.introspect.AnnotatedField;
import org.codehaus.jackson.map.introspect.AnnotatedMethod;
import org.codehaus.jackson.map.module.SimpleModule;
import org.codehaus.jackson.type.TypeReference;
/**
* <p>
* A collection of utility classes and (de)serializers to make Samza's job model
* work with Jackson. Rather than annotating Samza's job model directly, the
* Jackson-specific code is isolated so that Samza's core data model does not
* require a direct dependency on Jackson.
* </p>
*
* <p>
* To use Samza's job data model, use the SamzaObjectMapper.getObjectMapper()
* method.
* </p>
*/
public class SamzaObjectMapper {
private static final ObjectMapper OBJECT_MAPPER = getObjectMapper();
/**
* @return Returns a new ObjectMapper that's been configured to (de)serialize
* Samza's job data model, and simple data types such as TaskName,
* Partition, Config, and SystemStreamPartition.
*/
public static ObjectMapper getObjectMapper() {
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule("SamzaModule", new Version(1, 0, 0, ""));
// Setup custom serdes for simple data types.
module.addSerializer(Partition.class, new PartitionSerializer());
module.addSerializer(SystemStreamPartition.class, new SystemStreamPartitionSerializer());
module.addSerializer(TaskName.class, new TaskNameSerializer());
module.addDeserializer(Partition.class, new PartitionDeserializer());
module.addDeserializer(SystemStreamPartition.class, new SystemStreamPartitionDeserializer());
module.addDeserializer(Config.class, new ConfigDeserializer());
// Setup mixins for data models.
mapper.getSerializationConfig().addMixInAnnotations(TaskModel.class, JsonTaskModelMixIn.class);
mapper.getDeserializationConfig().addMixInAnnotations(TaskModel.class, JsonTaskModelMixIn.class);
mapper.getSerializationConfig().addMixInAnnotations(ContainerModel.class, JsonContainerModelMixIn.class);
mapper.getDeserializationConfig().addMixInAnnotations(ContainerModel.class, JsonContainerModelMixIn.class);
mapper.getSerializationConfig().addMixInAnnotations(JobModel.class, JsonJobModelMixIn.class);
mapper.getDeserializationConfig().addMixInAnnotations(JobModel.class, JsonJobModelMixIn.class);
// Convert camel case to hyphenated field names, and register the module.
mapper.setPropertyNamingStrategy(new CamelCaseToDashesStrategy());
mapper.registerModule(module);
return mapper;
}
public static class ConfigDeserializer extends JsonDeserializer<Config> {
@Override
public Config deserialize(JsonParser jsonParser, DeserializationContext context) throws IOException, JsonProcessingException {
ObjectCodec oc = jsonParser.getCodec();
JsonNode node = oc.readTree(jsonParser);
return new MapConfig(OBJECT_MAPPER.<Map<String, String>> readValue(node, new TypeReference<Map<String, String>>() {
}));
}
}
public static class PartitionSerializer extends JsonSerializer<Partition> {
@Override
public void serialize(Partition partition, JsonGenerator jsonGenerator, SerializerProvider provider) throws IOException, JsonProcessingException {
jsonGenerator.writeObject(Integer.valueOf(partition.getPartitionId()));
}
}
public static class PartitionDeserializer extends JsonDeserializer<Partition> {
@Override
public Partition deserialize(JsonParser jsonParser, DeserializationContext context) throws IOException, JsonProcessingException {
ObjectCodec oc = jsonParser.getCodec();
JsonNode node = oc.readTree(jsonParser);
return new Partition(node.getIntValue());
}
}
public static class TaskNameSerializer extends JsonSerializer<TaskName> {
@Override
public void serialize(TaskName taskName, JsonGenerator jsonGenerator, SerializerProvider provider) throws IOException, JsonProcessingException {
jsonGenerator.writeObject(taskName.toString());
}
}
public static class TaskNameDeserializer extends JsonDeserializer<TaskName> {
@Override
public TaskName deserialize(JsonParser jsonParser, DeserializationContext context) throws IOException, JsonProcessingException {
ObjectCodec oc = jsonParser.getCodec();
JsonNode node = oc.readTree(jsonParser);
return new TaskName(node.getTextValue());
}
}
public static class SystemStreamPartitionSerializer extends JsonSerializer<SystemStreamPartition> {
@Override
public void serialize(SystemStreamPartition systemStreamPartition, JsonGenerator jsonGenerator, SerializerProvider provider) throws IOException, JsonProcessingException {
Map<String, Object> systemStreamPartitionMap = new HashMap<String, Object>();
systemStreamPartitionMap.put("system", systemStreamPartition.getSystem());
systemStreamPartitionMap.put("stream", systemStreamPartition.getStream());
systemStreamPartitionMap.put("partition", systemStreamPartition.getPartition());
jsonGenerator.writeObject(systemStreamPartitionMap);
}
}
public static class SystemStreamPartitionDeserializer extends JsonDeserializer<SystemStreamPartition> {
@Override
public SystemStreamPartition deserialize(JsonParser jsonParser, DeserializationContext context) throws IOException, JsonProcessingException {
ObjectCodec oc = jsonParser.getCodec();
JsonNode node = oc.readTree(jsonParser);
String system = node.get("system").getTextValue();
String stream = node.get("stream").getTextValue();
Partition partition = new Partition(node.get("partition").getIntValue());
return new SystemStreamPartition(system, stream, partition);
}
}
/**
* A Jackson property naming strategy that converts camel case JSON fields to
* hyphenated names. For example, myVariableName would be converted to
* my-variable-name.
*/
public static class CamelCaseToDashesStrategy extends PropertyNamingStrategy {
@Override
public String nameForField(MapperConfig<?> config, AnnotatedField field, String defaultName) {
return convert(defaultName);
}
@Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(defaultName);
}
@Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(defaultName);
}
public String convert(String defaultName) {
StringBuilder builder = new StringBuilder();
char[] arr = defaultName.toCharArray();
for (int i = 0; i < arr.length; ++i) {
if (Character.isUpperCase(arr[i])) {
builder.append("-" + Character.toLowerCase(arr[i]));
} else {
builder.append(arr[i]);
}
}
return builder.toString();
}
}
}