org.wso2.ballerina.nativeimpl.lang.json.GetString.java Source code

Introduction

Here is the source code for org.wso2.ballerina.nativeimpl.lang.json.GetString.java

Source

/**
 * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. 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.wso2.ballerina.nativeimpl.lang.json;

import com.google.gson.JsonElement;
import com.google.gson.JsonPrimitive;
import com.jayway.jsonpath.InvalidPathException;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.JsonPathException;
import com.jayway.jsonpath.PathNotFoundException;
import com.jayway.jsonpath.ReadContext;
import org.wso2.ballerina.core.exception.BallerinaException;
import org.wso2.ballerina.core.interpreter.Context;
import org.wso2.ballerina.core.model.types.TypeEnum;
import org.wso2.ballerina.core.model.values.BJSON;
import org.wso2.ballerina.core.model.values.BString;
import org.wso2.ballerina.core.model.values.BValue;
import org.wso2.ballerina.core.nativeimpl.annotations.Argument;
import org.wso2.ballerina.core.nativeimpl.annotations.BallerinaFunction;
import org.wso2.ballerina.core.nativeimpl.annotations.ReturnType;
import org.wso2.ballerina.nativeimpl.lang.utils.ErrorHandler;

/**
 * Evaluate jsonpath on a JSON object and returns the string value.
 */
@BallerinaFunction(packageName = "ballerina.lang.json", functionName = "getString", args = {
        @Argument(name = "json", type = TypeEnum.JSON),
        @Argument(name = "jsonPath", type = TypeEnum.STRING) }, returnType = {
                @ReturnType(type = TypeEnum.STRING) }, isPublic = true)
public class GetString extends AbstractJSONFunction {

    private static final String OPERATION = "get string from json";

    @Override
    public BValue[] execute(Context ctx) {
        String jsonPath = null;
        BValue result = null;
        try {
            // Accessing Parameters.
            BJSON json = (BJSON) getArgument(ctx, 0);
            jsonPath = getArgument(ctx, 1).stringValue();

            // Getting the value from JSON
            ReadContext jsonCtx = JsonPath.parse(json.value());
            JsonElement element = jsonCtx.read(jsonPath);
            if (element == null) {
                throw new BallerinaException("No matching element found for jsonpath: " + jsonPath);
            } else if (element.isJsonPrimitive()) {
                // if the resulting value is a primitive, return the respective primitive value object
                JsonPrimitive value = element.getAsJsonPrimitive();
                if (value.isString()) {
                    result = new BString(value.getAsString());
                } else {
                    throw new BallerinaException("The element matching path: " + jsonPath + " is not a String.");
                }
            } else {
                throw new BallerinaException("The element matching path: " + jsonPath + " is not a String.");
            }
        } catch (PathNotFoundException e) {
            ErrorHandler.handleNonExistingJsonpPath(OPERATION, jsonPath, e);
        } catch (InvalidPathException e) {
            ErrorHandler.handleInvalidJsonPath(OPERATION, e);
        } catch (JsonPathException e) {
            ErrorHandler.handleJsonPathException(OPERATION, e);
        } catch (Throwable e) {
            ErrorHandler.handleJsonPathException(OPERATION, e);
        }

        // Setting output value.
        return getBValues(result);
    }
}