Java tutorial
/** * 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 com.gst.batch.service; import java.util.ArrayList; import java.util.List; import java.util.Map.Entry; import com.gst.batch.domain.BatchRequest; import com.gst.batch.domain.BatchResponse; import com.gst.infrastructure.core.serialization.FromJsonHelper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.jayway.jsonpath.JsonModel; /** * Provides methods to create dependency map among the various batchRequests. It * also provides method that takes care of dependency resolution among related * requests. * * @author Rishabh Shukla * @see BatchApiServiceImpl */ @Component public class ResolutionHelper { /** * Provides a Node like object for the request tree. * * @author Rishabh shukla * */ public class BatchRequestNode { private BatchRequest request; private final List<BatchRequestNode> childRequests = new ArrayList<>(); public BatchRequestNode() { super(); } public BatchRequest getRequest() { return this.request; } public void setRequest(BatchRequest request) { this.request = request; } public List<BatchRequestNode> getChildRequests() { return this.childRequests; } public void addChildRequest(final BatchRequestNode batchRequest) { this.childRequests.add(batchRequest); } } private FromJsonHelper fromJsonHelper; @Autowired public ResolutionHelper(final FromJsonHelper fromJsonHelper) { this.fromJsonHelper = fromJsonHelper; } /** * Returns a map containing requests that are divided in accordance of * dependency relations among them. Each different list is identified with a * "Key" which is the "requestId" of the request at topmost level in * dependency hierarchy of that particular list. * * @param batchRequests * @return List<ArrayList<BatchRequestNode>> */ public List<BatchRequestNode> getDependingRequests(final List<BatchRequest> batchRequests) { final List<BatchRequestNode> rootRequests = new ArrayList<>(); for (BatchRequest batchRequest : batchRequests) { if (batchRequest.getReference() == null) { final BatchRequestNode node = new BatchRequestNode(); node.setRequest(batchRequest); rootRequests.add(node); } else { this.addDependingRequest(batchRequest, rootRequests); } } return rootRequests; } private void addDependingRequest(final BatchRequest batchRequest, final List<BatchRequestNode> parentRequests) { for (BatchRequestNode batchRequestNode : parentRequests) { if (batchRequestNode.getRequest().getRequestId().equals(batchRequest.getReference())) { final BatchRequestNode dependingRequest = new BatchRequestNode(); dependingRequest.setRequest(batchRequest); batchRequestNode.addChildRequest(dependingRequest); } else { addDependingRequest(batchRequest, batchRequestNode.getChildRequests()); } } } /** * Returns a BatchRequest after dependency resolution. It takes a request * and the response of the request it is dependent upon as its arguments and * change the body or relativeUrl of the request according to parent * Request. * * @param request * @param lastResponse * @return BatchRequest */ public BatchRequest resoluteRequest(final BatchRequest request, final BatchResponse parentResponse) { // Create a duplicate request final BatchRequest br = request; final JsonModel responseJsonModel = JsonModel.model(parentResponse.getBody()); // Gets the body from current Request as a JsonObject final JsonObject jsonRequestBody = this.fromJsonHelper.parse(request.getBody()).getAsJsonObject(); JsonObject jsonResultBody = new JsonObject(); // Iterate through each element in the requestBody to find dependent // parameter for (Entry<String, JsonElement> element : jsonRequestBody.entrySet()) { final String key = element.getKey(); final JsonElement value = resolveDependentVariables(element, responseJsonModel); jsonResultBody.add(key, value); } // Set the body after dependency resolution br.setBody(jsonResultBody.toString()); // Also check the relativeUrl for any dependency resolution String relativeUrl = request.getRelativeUrl(); if (relativeUrl.contains("$.")) { String queryParams = ""; if (relativeUrl.contains("?")) { queryParams = relativeUrl.substring(relativeUrl.indexOf("?")); relativeUrl = relativeUrl.substring(0, relativeUrl.indexOf("?")); } final String[] parameters = relativeUrl.split("/"); for (String parameter : parameters) { if (parameter.contains("$.")) { final String resParamValue = responseJsonModel.get(parameter).toString(); relativeUrl = relativeUrl.replace(parameter, resParamValue); br.setRelativeUrl(relativeUrl + queryParams); } } } return br; } private JsonElement resolveDependentVariables(final Entry<String, JsonElement> entryElement, final JsonModel responseJsonModel) { JsonElement value = null; final JsonElement element = entryElement.getValue(); if (element.isJsonObject()) { final JsonObject jsObject = element.getAsJsonObject(); value = processJsonObject(jsObject, responseJsonModel); } else if (element.isJsonArray()) { final JsonArray jsElementArray = element.getAsJsonArray(); value = processJsonArray(jsElementArray, responseJsonModel); } else { value = resolveDependentVariable(element, responseJsonModel); } return value; } private JsonElement processJsonObject(final JsonObject jsObject, final JsonModel responseJsonModel) { JsonObject valueObj = new JsonObject(); for (Entry<String, JsonElement> element : jsObject.entrySet()) { final String key = element.getKey(); final JsonElement value = resolveDependentVariable(element.getValue(), responseJsonModel); valueObj.add(key, value); } return valueObj; } private JsonArray processJsonArray(final JsonArray elementArray, final JsonModel responseJsonModel) { JsonArray valueArr = new JsonArray(); for (JsonElement element : elementArray) { if (element.isJsonObject()) { final JsonObject jsObject = element.getAsJsonObject(); valueArr.add(processJsonObject(jsObject, responseJsonModel)); } } return valueArr; } private JsonElement resolveDependentVariable(final JsonElement element, final JsonModel responseJsonModel) { JsonElement value = element; String paramVal = element.getAsString(); if (paramVal.contains("$.")) { // Get the value of the parameter from parent response final String resParamValue = responseJsonModel.get(paramVal).toString(); value = this.fromJsonHelper.parse(resParamValue); } return value; } }