cozo-lib-java

Java bindings for CozoDb.

Install

Artefacts are on Clojars. For Gradle:

implementation("com.github.zh217:cozo-lib-java:0.1.0")

For Maven:

<dependency>
  <groupId>com.github.zh217</groupId>
  <artifactId>cozo-lib-java</artifactId>
  <version>0.1.0</version>
</dependency>

You will need to add the maven repo https://clojars.org/repo to your package manager.

This project only uses Clojure for packaging, there is no Clojure dependency in code. If you use clojure, please use cozo-clj instead.

Usage

Import org.cozodb.CozoDb and

// Create and open
CozoDb db = new CozoDb("_test_db");

// Query. Everything is string, 
// you need to use your own JSON library for parsing and encoding
System.out.println(db.query("?[] <- [['hello', 'world!']]", ""));
System.out.println(db.query("?[] <- [['hello', 'world', $name]]", 
                            "{\"name\":\"Java\"}"));
System.out.println(db.query("?[a] <- [[1, 2]]", ""));

// Close
db.close();

It is recommended to close the database object when you are done with it, otherwise the native resources will not be released until your program quits.

How it works

This library requires the native JNI dynamic library to be present in ~/.cozo_java_native_lib/. If not found, it will attempt to download one from the release page for your system. When this happens, you will get messages printed to stderr telling you what exactly is happening. The download only happens once for each version.

In case a pre-compiled native library is not available for your system, you will get an error when you import CozoDb.

Compilation of the native library

You need to build the dynamic library for Java from the Cozo main repo. After that, copy the dynamic library to ~/.cozo_java_native_lib/ so that this package can find it. You may need to rename your dynamic library: you can see what name is required from the message this package prints when it attempts to download from the release page.