com.fasterxml.jackson.tools.Jackson.java Source code

Introduction

Here is the source code for com.fasterxml.jackson.tools.Jackson.java

Source

/******************************************************************************
 * * This data and information is proprietary to, and a valuable trade secret
 * * of, Basis Technology Corp.  It is given in confidence by Basis Technology
 * * and may only be used as permitted under the license agreement under which
 * * it has been distributed, and in no other way.
 * *
 * * Copyright (c) 2015 Basis Technology Corporation All rights reserved.
 * *
 * * The technical data and information provided herein are provided with
 * * `limited rights', and the computer software provided herein is provided
 * * with `restricted rights' as those terms are defined in DAR and ASPR
 * * 7-104.9(a).
 ******************************************************************************/

package com.fasterxml.jackson.tools;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
import com.fasterxml.jackson.dataformat.avro.AvroFactory;
import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
import com.fasterxml.jackson.dataformat.csv.CsvFactory;
import com.fasterxml.jackson.dataformat.protobuf.ProtobufFactory;
import com.fasterxml.jackson.dataformat.smile.SmileFactory;
import com.fasterxml.jackson.dataformat.xml.XmlFactory;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
import com.google.common.io.ByteSink;
import com.google.common.io.ByteSource;
import com.google.common.io.Files;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.CmdLineException;
import org.kohsuke.args4j.CmdLineParser;
import org.kohsuke.args4j.Option;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Command-line utility to Jackson
 */
public final class Jackson {

    /**
     * Supported formats.
     * Perhaps could be introspected.
     */
    enum Format {
        JSON, YAML, SMILE, CBOR, XML, CSV, AVRO, PROTOBUF;
    }

    @Argument(index = 0, required = true, usage = "The input file.", metaVar = "INPUT")
    File inputFile;

    @Argument(index = 1, required = true, usage = "The format of the input file.", metaVar = "INPUT_FORMAT")
    Format inputFormat;

    @Argument(index = 2, required = true, usage = "The output file.", metaVar = "OUTPUT")
    File outputFile;

    @Argument(index = 3, required = true, usage = "The format of the output file.", metaVar = "OUTPUT_FORMAT")
    Format outputFormat;

    @Option(name = "-pretty", usage = "Enable pretty-printing.")
    boolean pretty;

    public static void main(String[] args) {
        Jackson that = new Jackson();
        CmdLineParser parser = new CmdLineParser(that);
        try {
            parser.parseArgument(args);
            that.run();
        } catch (CmdLineException e) {
            // handling of wrong arguments
            System.err.println(e.getMessage());
            parser.printUsage(System.err);
        }
    }

    private void run() {
        ByteSource inputSource = Files.asByteSource(inputFile);
        ByteSink outputSink = Files.asByteSink(outputFile);
        InputStream input;
        OutputStream output;
        try {
            input = inputSource.openBufferedStream();
            output = outputSink.openBufferedStream();
            convert(input, output);
        } catch (IOException e) {
            System.err.format("Exception in conversion %s%n", e.getMessage());
            System.exit(1);
        }
    }

    private void convert(InputStream input, OutputStream output) throws IOException {
        JsonFactory inputFactory = factory(inputFormat);
        JsonParser parser = inputFactory.createParser(input);
        JsonFactory outputFactory = factory(outputFormat);
        JsonGenerator generator = outputFactory.createGenerator(output);
        if (pretty) {
            generator.setPrettyPrinter(new DefaultPrettyPrinter());
        }
        JsonToken token;
        while ((token = parser.nextToken()) != null) {
            switch (token) {
            case START_OBJECT:
                generator.writeStartObject();
                break;
            case END_OBJECT:
                generator.writeEndObject();
                break;
            case START_ARRAY:
                generator.writeStartArray();
                break;
            case END_ARRAY:
                generator.writeEndArray();
                break;
            case FIELD_NAME:
                generator.writeFieldName(parser.getCurrentName());
                break;
            case VALUE_STRING:
                generator.writeString(parser.getValueAsString());
                break;
            case VALUE_NUMBER_INT:
                generator.writeNumber(parser.getValueAsInt());
                break;
            case VALUE_NUMBER_FLOAT:
                generator.writeNumber(parser.getValueAsDouble());
                break;
            case VALUE_TRUE:
                generator.writeBoolean(true);
                break;
            case VALUE_FALSE:
                generator.writeBoolean(false);
                break;
            case VALUE_NULL:
                generator.writeNull();
            default:
                System.err.format("Impossible token %s%n", token);
                System.exit(1);
            }
        }
    }

    private JsonFactory factory(Format format) {
        switch (format) {
        case JSON:
            return new JsonFactory();
        case YAML:
            return new YAMLFactory();
        case SMILE:
            return new SmileFactory();
        case CBOR:
            return new CBORFactory();
        case XML:
            return new XmlFactory();
        case CSV:
            return new CsvFactory();
        case AVRO:
            return new AvroFactory();
        case PROTOBUF:
            return new ProtobufFactory();
        }
        throw new RuntimeException("Invalid format");
    }
}