allegro/json-avro-converter

Name: json-avro-converter

Owner: Allegro Tech

Description: JSON to Avro conversion tool designed to make migration to Avro easier.

Created: 2016-02-05 11:56:25.0

Updated: 2018-01-18 19:03:07.0

Pushed: 2017-10-20 12:16:41.0

Homepage: null

Size: 135

Language: Groovy

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README

json-avro-converter

JSON to Avro conversion tool designed to make migration to Avro easier. Includes simple command line validator.

Motivation

Apache Avro ships with some very advanced and efficient tools for reading and writing binary Avro but their support for JSON to Avro conversion is unfortunately limited and requires wrapping fields with type declarations if you have some optional fields in your schema. This tool is supposed to help with migrating project from using JSON to Avro without having to modify JSON data if it conforms to the JSON schema.

JSON2Avro Converter

Features

• conversion binary JSON to binary Avro
• conversion binary JSON to GenericData.Record
• conversion binary Avro to binary JSON
• optional field support (unions do not require wrapping)
• unknown fields that are not declared in schema are ignored

Dependencies

ndencies {
compile group: 'tech.allegro.schema.json2avro', name: 'converter', version: '0.2.5'

Basic usage

rt tech.allegro.schema.json2avro.converter.AvroConversionException;
rt tech.allegro.schema.json2avro.converter.JsonAvroConverter;
rt org.apache.avro.generic.GenericData;
rt org.apache.avro.Schema;

vro schema with one string field: username
ng schema =
        "{" +
        "   \"type\" : \"record\"," +
        "   \"name\" : \"Acme\"," +
        "   \"fields\" : [{ \"name\" : \"username\", \"type\" : \"string\" }]" +
        "}";

ng json = "{ \"username\": \"mike\" }";

AvroConverter converter = new JsonAvroConverter();

onversion to binary Avro
[] avro = converter.convertToAvro(json.getBytes(), schema);

onversion to GenericData.Record
ricData.Record record = converter.convertToGenericDataRecord(json.getBytes(), new Schema.Parser().parse(schema));

onversion from binary Avro to JSON
[] binaryJson = converter.convertToJson(avro, schema);

xception handling
ng invalidJson = "{ \"username\": 8 }";    

{
converter.convertToAvro(invalidJson.getBytes(), schema);    
tch (AvroConversionException ex) {
System.err.println("Caught exception: " + ex.getMessage());

Validator

A command line tool for validating your JSON/Avro documents against the schema.

Build

To bundle the tool into single executable JAR:

adlew :validator:shadowJar
 -jar validator/build/libs/json2avro-validator-{version}.jar --help

Usage

Running Validator with --help option will print help message listing all possible arguments. Sample Avro schema and messages can be found in:

• schema: validator/src/test/resources/user.avcs
• JSON message: validator/src/test/resources/user.json
• Avro message: validator/src/test/resources/user.avro

JSON to Avro

You can validate your JSON to Avro conversion:

 -jar json2avro-validator.jar -s user.avcs -i user.json

If everything will process correctly, the process will end with zero status code.

Avro to JSON

You can convert the Avro binary data into JSON by setting mode -m avro2json option:

 -jar json2avro-validator.jar -s user.avcs -i user.avro -m avro2json

JSON to Avro to JSON

If you would like to know how message will look like after encoding and decoding invoke:

 -jar json2avro-validator.jar -s user.avcs -i user.json -m json2avro2json

License

json-avro-converter is published under Apache License 2.0.