Java tutorial
/******************************************************************************* * (c) Copyright 2014 Hewlett-Packard Development Company, L.P. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Apache License v2.0 which accompany this distribution. * * The Apache License is available at * http://www.apache.org/licenses/LICENSE-2.0 * *******************************************************************************/ package io.cloudslang.content.json.actions; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ObjectNode; import com.hp.oo.sdk.content.annotations.Action; import com.hp.oo.sdk.content.annotations.Output; import com.hp.oo.sdk.content.annotations.Param; import com.hp.oo.sdk.content.annotations.Response; import com.hp.oo.sdk.content.plugin.ActionMetadata.MatchType; import com.hp.oo.sdk.content.plugin.ActionMetadata.ResponseType; import io.cloudslang.content.constants.OutputNames; import io.cloudslang.content.constants.ResponseNames; import io.cloudslang.content.constants.ReturnCodes; import io.cloudslang.content.json.utils.Constants; import io.cloudslang.content.utils.StringUtilities; import java.util.HashMap; import java.util.Map; import static io.cloudslang.content.json.utils.JsonUtils.populateResult; /** * Created by ioanvranauhp * Date 2/5/2015. */ public class GetValueFromObject { private static final String ESCAPED_SLASH = "\\"; /** * This operation accepts an object in the JavaScript Object Notation format (JSON) and returns a value for the specified key. * * @param object The string representation of a JSON object. * Objects in JSON are a collection of name value pairs, separated by a colon and surrounded with curly brackets {}. * The name must be a string value, and the value can be a single string or any valid JSON object or array. * Examples: {"one":1, "two":2}, {"one":{"a":"a","B":"B"}, "two":"two", "three":[1,2,3.4]} * @param key The key in the object to get the value of. * Examples: city, location[0].city * @return a map containing the output of the operation. Keys present in the map are: * <p/> * <br><br><b>returnResult</b> - This will contain the value for the specified key in the object. * <br><b>exception</b> - In case of success response, this result is empty. In case of failure response, * this result contains the java stack trace of the runtime exception. * <br><br><b>returnCode</b> - The returnCode of the operation: 0 for success, -1 for failure. */ @Action(name = "Get Value from Object", outputs = { @Output(OutputNames.RETURN_RESULT), @Output(OutputNames.RETURN_CODE), @Output(OutputNames.EXCEPTION) }, responses = { @Response(text = ResponseNames.SUCCESS, field = OutputNames.RETURN_CODE, value = ReturnCodes.SUCCESS, matchType = MatchType.COMPARE_EQUAL, responseType = ResponseType.RESOLVED), @Response(text = ResponseNames.FAILURE, field = OutputNames.RETURN_CODE, value = ReturnCodes.FAILURE, matchType = MatchType.COMPARE_EQUAL, responseType = ResponseType.ERROR, isOnFail = true) }) public Map<String, String> execute(@Param(value = Constants.InputNames.OBJECT, required = true) String object, @Param(value = Constants.InputNames.KEY, required = true) String key) { Map<String, String> returnResult = new HashMap<>(); if (StringUtilities.isBlank(object)) { return populateResult(returnResult, new Exception("Empty object provided!")); } if (key == null) { return populateResult(returnResult, new Exception("Null key provided!")); } final JsonNode jsonRoot; ObjectMapper objectMapper = new ObjectMapper(); try { jsonRoot = objectMapper.readTree(object); } catch (Exception exception) { final String value = "Invalid object provided! " + exception.getMessage(); return populateResult(returnResult, value, exception); } int startIndex = 0; final JsonNode valueFromObject; try { valueFromObject = getObject(jsonRoot, key.split(ESCAPED_SLASH + "."), startIndex); } catch (Exception exception) { return populateResult(returnResult, exception); } if (valueFromObject.isValueNode()) { return populateResult(returnResult, valueFromObject.asText(), null); } else { return populateResult(returnResult, valueFromObject.toString(), null); } } private JsonNode getObject(JsonNode jsonObject, String[] keys, int startIndex) throws Exception { if (startIndex >= keys.length) { return jsonObject; } String aKey = keys[startIndex]; if (jsonObject instanceof ObjectNode) { //base case if (keys.length == 0) return getValue(jsonObject, aKey); //recursive call else { final ObjectNode newJsonObject; final JsonNode valueFromKey = getValue(jsonObject, aKey); if (valueFromKey instanceof ObjectNode) { newJsonObject = (ObjectNode) valueFromKey; } else { return valueFromKey; } return getObject(newJsonObject, keys, ++startIndex); } } else { throw new Exception("The key does not exist in JavaScript object!"); } } private JsonNode getValue(JsonNode jsonElement, String aKey) throws Exception { //non JSON array object if (!aKey.matches(".*" + ESCAPED_SLASH + "[[0-9]+]$")) { if (jsonElement.get(aKey) != null) { return jsonElement.get(aKey); } else throw new Exception("The " + aKey + " key does not exist in JavaScript object!"); } //JSON array object else { int startIndex = aKey.indexOf("["); int endIndex = aKey.indexOf("]"); String oneKey = aKey.substring(0, startIndex); int index = 0; try { index = Integer.parseInt(aKey.substring(startIndex + 1, endIndex)); } catch (NumberFormatException e) { throw new Exception("Invalid index provided: " + index); } JsonNode subObject; subObject = jsonElement.get(oneKey); if (jsonElement.get(oneKey) != null) { if (subObject instanceof ArrayNode) { final ArrayNode asJsonArray = (ArrayNode) subObject; if ((index >= asJsonArray.size()) || (index < 0)) { throw new Exception("The provided " + index + " index is out of range! Provide a valid index value in the provided JSON!"); } else { return asJsonArray.get(index); } } else { throw new Exception("Invalid json array provided: " + subObject.toString() + " "); } } else { throw new Exception("The " + aKey + " key does not exist in JavaScript object!"); } } } }