Immutable Json library for java

This project attempts to build and AST ( Abstract Syntactic Tree ) for Json and provide a useful way to work with that tree.

Note

Starting with version 8, we require JDK17.

Status

Community

Adopters

Are you using immutable-json? Please consider opening a pull request to list your organization here:

• Your Organization here

Related projects

• Siren.java
• Collection JSON (Java)

Usage

A short example showing encoding/decoding of a few different types. Also note that the Tuples type is from net.hamnaberg.json.util to have Tuple constructors up to Tuple27

    static class Event {
        public final UUID ID;
        public final List<String> tags;
        public final String message;

        public Event(UUID ID, List<String> tags, String message) {
            this.ID = ID;
            this.tags = tags;
            this.message = message;
        }
    }

    @Test
    public void testEvent() throws Exception {
        String expected = "{"+
                      "\"id\":\"1e2f28ff-54b5-4ad4-9edb-36712dc52202\","+
                      "\"tags\":[\"travel\",\"code\"],"+
                      "\"message\":\"This is a test\""+
                   "}";

        // create a decoder for our Event
        DecodeJson<Event> decode = Decoders.decode(
                Decoders.DUUID.fieldDecoder("id"),
                FieldDecoder.TList("tags", Decoders.DString).withDefaultValue(Collections.emptyList()),
                FieldDecoder.TString("message"),
                Event::new
        );

        // create an encoder that will encode our Event into json
        EncodeJson<Event> encode = Encoders.encode(
                Encoders.EUUID.fieldEncoder("id"),
                FieldEncoder.EList("tags", Encoders.EString),
                FieldEncoder.EString("message")
        ).contramap(event -> Tuples.of(event.ID, event.tags, event.message));

        // a codec can both encode and decode a value
        JsonCodec<Event> codec = JsonCodec.lift(decode, encode);

        // parse raw json with help of jackson parser
        Json.JValue jValue = new JacksonStreamingParser().parse(expected);

        String json = codec
                .toJson(codec.fromJson(jValue).unsafeGet())
                .nospaces();

        assertThat(json).isEqualTo(expected);
    }

Where can we find this

Using maven, you download it from Maven Central using these coordinates:

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-ast</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-pointer</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-patch</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-jackson</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-javax</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-gson</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-codec</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

<dependency>
  <groupId>net.hamnaberg.json</groupId>
  <artifactId>immutable-json-reflection-codec</artifactId>
  <version>VERSION</version> <!-- Version from badge -->
</dependency>

Snapshots can be found from Sonatype:

License

We are using the Apache License 2.0

Contributing

All contributions are welcome! Documentation is sorely lacking and really needs some love. If you find a missing combinator, please open a PR or issue so we can discuss it. Any bugfixes or pointing out missing features are also welcome.