Jq4J

Jq4J is jq running as pure Java bytecode.

Why?

jq is a very handy tool we all use everyday, sadly it's syntax doesn't follow a spec that can be easily ported across languages. By compiling jq to Wasm and Wasm to Java bytecode thanks to Chicory we don't need to port the original source code and we have 1:1 functionality out-of-the-box.

Quick Start

Add Jq4J as a standard Maven dependency:

<dependency>
    <groupId>io.roastedroot</groupId>
    <artifactId>jq4j</artifactId>
</dependency>

The usage matches 1:1 the usage through the jq CLI, hence you should:

• define the command line arguments to be used
• pass the input over on stdin
• extract the output as stdout

In case of any error you can always inspect stdout/stderr produced by jq to identify the issue. Example:

import io.roastedroot.jq4j.Jq;

var result = Jq.builder()
    .withStdin("{\"foo\": 0}".getBytes(UTF_8))
    .withArgs("-M", "--compact-output", ".")
    .run();

if (result.success()) {
    var resultStr = new String(result.stdout(), UTF_8); // {"foo":0}\n
    ...
} else {
    System.out.println(result.stdout());
    System.err.println(result.stderr());
}

Building the Project

To build this project, you'll need:

• Docker
• JDK 11 or newer
• Maven

Steps:

make build
mvn clean install

Acknowledgements

This project stands on the shoulders of giants:

• go-jq - go-jq is a distribution of jq, that can be built with Go
• Chicory – a native JVM WebAssembly runtime