/**
* JBoss, Home of Professional Open Source
* Copyright Red Hat, Inc., and individual contributors.
*
* 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.jboss.aerogear.unifiedpush.rest.util;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.github.fge.jackson.JacksonUtils;
import com.github.fge.jsonpatch.JsonPatch;
import com.github.fge.jsonpatch.JsonPatchException;
import org.jboss.aerogear.unifiedpush.rest.util.transform.DynamicTransformer;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Basic request transformer
*/
public class RequestTransformer {
private final Logger logger = Logger.getLogger(RequestTransformer.class.getName());
private static final String OPERATIONS = "operations";
private static final String TRANSFORMER = "dynamicTransformer";
public StringBuilder transform(String path, String version, StringBuilder json) {
try {
final JsonNode node = locateJsonPatch(path, version);
final JsonNode operations = node.findPath(OPERATIONS);
final JsonNode patch;
if (patchHasDynamicTransformer(operations)) {
patch = operations;
} else {
patch = node;
}
final JsonNode patched = transformJson(patch, json);
return convertToStringBuilder(applyDynamicTransformer(patched, node));
} catch (IOException e) {
logger.log(Level.SEVERE, String.format("could not find/load path file for version '%s' and path '%s'", version, path), e);
return json;
} catch (JsonPatchException e) {
throw new RuntimeException("Error in json patch file", e);
}
}
private boolean patchHasDynamicTransformer(JsonNode operations) {
return !operations.isMissingNode();
}
private JsonNode locateJsonPatch(String path, String version) throws IOException {
return JacksonUtils.getReader().readTree(getClass().getResourceAsStream(path + "/" + version + ".json"));
}
private JsonNode transformJson(JsonNode patch, StringBuilder json) throws IOException, JsonPatchException {
JsonNode jsonNode = convertToJsonNode(json);
for (JsonNode operation : patch) {
try {
final ArrayNode nodes = JsonNodeFactory.instance.arrayNode();
nodes.add(operation);
JsonPatch patchOperation = JsonPatch.fromJson(nodes);
jsonNode = patchOperation.apply(jsonNode);
} catch (JsonPatchException e) {
logger.log(Level.FINEST, "ignore field not found");
}
}
return jsonNode;
}
private JsonNode convertToJsonNode(StringBuilder json) throws IOException {
return JacksonUtils.getReader().readTree(json.toString());
}
private StringBuilder convertToStringBuilder(JsonNode dynamicTransformedNode) {
return new StringBuilder(dynamicTransformedNode.toString());
}
JsonNode applyDynamicTransformer(JsonNode json, JsonNode patch) throws IOException {
String clazz = patch.findPath(TRANSFORMER).textValue();
if (clazz != null) {
try {
final DynamicTransformer dynamicTransformer = (DynamicTransformer) Class.forName(getClass().getPackage().getName() + ".transform." + clazz).newInstance();
return dynamicTransformer.transform(json);
} catch (Exception e) {
throw new RuntimeException("error in json patch could not instantiate / find dynamic transformer", e);
}
}
return json;
}
}