/*
* Copyright 2013 the original author or authors.
*
* 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.springframework.yarn.integration.convert;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.convert.converter.Converter;
import org.springframework.util.ClassUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.yarn.integration.ip.mind.MindRpcMessageHolder;
import org.springframework.yarn.integration.ip.mind.binding.BaseObject;
import com.fasterxml.jackson.databind.ObjectMapper;
/**
* Spring {@link Converter} which knows how to convert
* {@link MindRpcMessageHolder} to {@link BaseObject}.
*
* @author Janne Valkealahti
*
*/
public class MindHolderToObjectConverter implements Converter<MindRpcMessageHolder, BaseObject> {
private final static Log log = LogFactory.getLog(MindHolderToObjectConverter.class);
/** Jackson object mapper */
private ObjectMapper objectMapper;
/** Base package prefixes */
private String[] basePackage;
/** Simple class cache*/
private Map<String, Class<? extends BaseObject>> classCache;
/**
* Instantiates a new mind holder to object converter.
*
* @param objectMapper the object mapper
*/
public MindHolderToObjectConverter(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
this.classCache = new ConcurrentHashMap<String, Class<? extends BaseObject>>();
}
/**
* Instantiates a new mind holder to object converter.
*
* @param objectMapper the object mapper
* @param basePackage the base package
*/
public MindHolderToObjectConverter(ObjectMapper objectMapper, String basePackage) {
this(objectMapper, new String[]{basePackage});
}
/**
* Instantiates a new mind holder to object converter.
*
* @param objectMapper the object mapper
* @param basePackage the array of base packages
*/
public MindHolderToObjectConverter(ObjectMapper objectMapper, String basePackage[]) {
this.objectMapper = objectMapper;
this.basePackage = basePackage;
this.classCache = new ConcurrentHashMap<String, Class<? extends BaseObject>>();
}
@Override
public BaseObject convert(MindRpcMessageHolder source) {
Map<String, String> headers = source.getHeaders();
String type = headers.get("type").trim();
byte[] content = source.getContent();
Class<?> clazz = resolveClass(type);
if (clazz == null) {
throw new MindDataConversionException("Failed to convert source object. Can't resolve type=" + type);
}
try {
BaseObject object = (BaseObject) objectMapper.readValue(content, clazz);
return object;
} catch (Exception e) {
throw new MindDataConversionException("Failed to convert source object.", e);
}
}
/**
* Sets the base packages.
*
* @param basePackage the new array base packages
*/
public void setBasePackage(String[] basePackage) {
this.basePackage = basePackage;
}
/**
* Resolve the class.
*
* @param type the type
* @return the class
*/
@SuppressWarnings("unchecked")
private Class<?> resolveClass(String type) {
String clazzName = type;
Class<?> clazz = classCache.get(clazzName);
if (clazz == null) {
try {
clazz = ClassUtils.resolveClassName(clazzName, getClass().getClassLoader());
} catch (IllegalArgumentException e) {
}
if (clazz != null) {
classCache.put(clazzName, (Class<? extends BaseObject>) clazz);
}
}
if (clazz != null) {
return clazz;
}
if (!ObjectUtils.isEmpty(basePackage)) {
for (String base : basePackage) {
clazzName = base + "." + type;
if (log.isDebugEnabled()) {
log.debug("Trying to resolve type " + type + " as " + clazzName);
}
clazz = classCache.get(clazzName);
if (log.isDebugEnabled() && clazz != null) {
log.debug("Found " + clazz + " from a cache");
}
if (clazz == null) {
try {
clazz = ClassUtils.resolveClassName(clazzName, getClass().getClassLoader());
} catch (IllegalArgumentException e) {
}
if (clazz != null) {
classCache.put(clazzName, (Class<? extends BaseObject>) clazz);
}
}
if (clazz != null) {
return clazz;
}
}
}
return clazz;
}
}