/*
* 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.nifi.web.standard.api.transformjson;
import java.io.File;
import java.io.FilenameFilter;
import java.util.Collections;
import java.util.Map;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import org.apache.commons.lang3.StringUtils;
import org.apache.nifi.attribute.expression.language.PreparedQuery;
import org.apache.nifi.attribute.expression.language.Query;
import org.apache.nifi.processors.standard.util.jolt.TransformUtils;
import org.apache.nifi.util.file.classloader.ClassLoaderUtils;
import org.apache.nifi.processors.standard.util.jolt.TransformFactory;
import org.apache.nifi.web.standard.api.AbstractStandardResource;
import org.apache.nifi.web.standard.api.transformjson.dto.JoltSpecificationDTO;
import org.apache.nifi.web.standard.api.transformjson.dto.ValidationDTO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.bazaarvoice.jolt.JoltTransform;
import com.bazaarvoice.jolt.JsonUtils;
@Path("/standard/transformjson")
public class TransformJSONResource extends AbstractStandardResource {
private static final Logger logger = LoggerFactory.getLogger(TransformJSONResource.class);
private final static String DEFAULT_CHARSET = "UTF-8";
protected Object getSpecificationJsonObject(JoltSpecificationDTO specificationDTO, boolean evaluateAttributes){
if (!StringUtils.isEmpty(specificationDTO.getSpecification()) ){
final String specification;
if(evaluateAttributes) {
PreparedQuery preparedQuery = Query.prepare(specificationDTO.getSpecification());
Map<String, String> attributes = specificationDTO.getExpressionLanguageAttributes() == null ? Collections.emptyMap() : specificationDTO.getExpressionLanguageAttributes();
specification = preparedQuery.evaluateExpressions(attributes, null);
}else{
specification = specificationDTO.getSpecification().replaceAll("\\$\\{","\\\\\\\\\\$\\{");
}
return JsonUtils.jsonToObject(specification, DEFAULT_CHARSET);
}else{
return null;
}
}
@POST
@Produces({MediaType.APPLICATION_JSON})
@Path("/validate")
public Response validateSpec(JoltSpecificationDTO specificationDTO) {
try {
getTransformation(specificationDTO,false);
}catch(final Exception e){
logger.error("Validation Failed - " + e.toString());
return Response.ok(new ValidationDTO(false,"Validation Failed - Please verify the provided specification.")).build();
}
return Response.ok(new ValidationDTO(true,null)).build();
}
@POST
@Produces({MediaType.APPLICATION_JSON})
@Path("/execute")
public Response executeSpec(JoltSpecificationDTO specificationDTO) {
try {
JoltTransform transform = getTransformation(specificationDTO,true);
Object inputJson = JsonUtils.jsonToObject(specificationDTO.getInput());
return Response.ok(JsonUtils.toJsonString(TransformUtils.transform(transform,inputJson))).build();
}catch(final Exception e){
logger.error("Execute Specification Failed - " + e.toString());
return Response.status(Response.Status.INTERNAL_SERVER_ERROR).build();
}
}
protected JoltTransform getTransformation(JoltSpecificationDTO specificationDTO, boolean evaluateAttributes) throws Exception{
Object specJson = getSpecificationJsonObject(specificationDTO,evaluateAttributes);
String transformName = specificationDTO.getTransform();
String modules = specificationDTO.getModules();
ClassLoader classLoader = null;
JoltTransform transform ;
if(modules != null && !modules.isEmpty()){
classLoader = ClassLoaderUtils.getCustomClassLoader(specificationDTO.getModules(),this.getClass().getClassLoader(), getJarFilenameFilter());
} else{
classLoader = this.getClass().getClassLoader();
}
if(transformName.equals("jolt-transform-custom")) {
transform = TransformFactory.getCustomTransform(classLoader,specificationDTO.getCustomClass(), specJson);
}else{
transform = TransformFactory.getTransform(classLoader,specificationDTO.getTransform(), specJson);
}
return transform;
}
protected FilenameFilter getJarFilenameFilter(){
return new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return (name != null && name.endsWith(".jar"));
}
};
}
}