com.bazaarvoice.jolt.JoltCliUtilities.java Source code

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Here is the source code for com.bazaarvoice.jolt.JoltCliUtilities.java

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/*
 * Copyright 2013 Bazaarvoice, Inc.
 *
 * 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 com.bazaarvoice.jolt;

import com.fasterxml.jackson.core.JsonParseException;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

/**
 * A utility class for the Jolt CLI tool.
 */
public class JoltCliUtilities {

    public static final String DIFFY_COMMAND_IDENTIFIER = "diffy";
    public static final String SORT_COMMAND_IDENTIFIER = "sort";
    public static final String TRANSFORM_COMMAND_IDENTIFIER = "transform";

    /**
     * Prints the given string to standard out, or doesn't, based on the suppressOutput flag
     */
    public static void printToStandardOut(String output, boolean suppressOutput) {
        if (!suppressOutput) {
            System.out.println(output);
        }
    }

    /**
     * Uses the File to build a Map containing JSON data found in the file. This method will
     * System exit with an error code of 1 if has any trouble opening the file or the file did not
     * contain properly formatted JSON (i.e. the JSON parser was unable to parse its contents)
     *
     * @return the Map containing the JSON data
     */
    public static Object createJsonObjectFromFile(File file, boolean suppressOutput) {
        Object jsonObject = null;
        try {
            FileInputStream inputStream = new FileInputStream(file);
            jsonObject = JsonUtils.jsonToObject(inputStream);
            inputStream.close();
        } catch (IOException e) {
            if (e instanceof JsonParseException) {
                printToStandardOut("File " + file.getAbsolutePath() + " did not contain properly formatted JSON.",
                        suppressOutput);
            } else {
                printToStandardOut("Failed to open file: " + file.getAbsolutePath(), suppressOutput);
            }
            System.exit(1);
        }
        return jsonObject;
    }

    /**
     * Prints the given json object to standard out, accounting for pretty printing and suppressed output.
     *
     * @param output The object to print. This method will fail if this object is not well formed JSON.
     * @param uglyPrint ignore pretty print
     * @param suppressOutput suppress output to standard out
     * @return true if printing operation was successful
     */
    public static boolean printJsonObject(Object output, Boolean uglyPrint, boolean suppressOutput) {
        try {
            if (uglyPrint) {
                printToStandardOut(JsonUtils.toJsonString(output), suppressOutput);
            } else {
                printToStandardOut(JsonUtils.toPrettyJsonString(output), suppressOutput);
            }
        } catch (Exception e) {
            printToStandardOut("An error occured while attempting to print the output.", suppressOutput);
            return false;
        }
        return true;
    }

    /**
     * This method will read in JSON, either from the given file or from standard in
     * if the file is null. An object contain the ingested input is returned.
     *
     * @param file the file to read the input from, or null to use standard in
     * @param suppressOutput suppress output of error messages to standard out
     * @return Object containing input if successful or null if an error occured
     */
    public static Object readJsonInput(File file, boolean suppressOutput) {
        Object jsonObject;
        if (file == null) {
            try {
                jsonObject = JsonUtils.jsonToMap(System.in);
            } catch (Exception e) {
                if (e instanceof JsonParseException) {
                    printToStandardOut("Standard input did not contain properly formatted JSON.", suppressOutput);
                } else {
                    printToStandardOut("Failed to process standard input.", suppressOutput);
                }
                return null;
            }
        } else {
            jsonObject = createJsonObjectFromFile(file, suppressOutput);
        }
        return jsonObject;
    }
}