Merge 'Add support for Java bindings' from Kim Seon Woo

Purpose of this PR

- Add support for Java (as Java has an extensive community)
- Enable Limbo to be provided as a Java library in the future.

Changes

- Added `bindings/java` directory.
- Created `src` package for Java (Gradle) and `rs_src` for Rust JNI
code.
- Implemented basic functionality to gather feedback and proceed with
further development.
  - Some features just printout the result for testing purposes.

Future Work

- Integrate CI to publish the library.
- Enhance error handling mechanisms.
- Implement additional features and functionality.
- Add test code after we decide on which features to provide

Issue

#615

Closes #613

Cargo.toml

@@ -3,6 +3,7 @@
 [workspace]
 resolver = "2"
 members = [
+    "bindings/java",
     "bindings/python",
     "bindings/wasm",
     "cli",

bindings/java/.gitignore

@@ -0,0 +1,39 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### IntelliJ IDEA ###
+.idea/
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

bindings/java/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "java-limbo"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+
+[lib]
+name = "_limbo_java"
+crate-type = ["cdylib"]
+path = "rs_src/lib.rs"
+
+[dependencies]
+anyhow = "1.0"
+limbo_core = { path = "../../core" }
+jni = "0.21.1"
+rand = { version = "0.8.5", features = [] }
+lazy_static = "1.5.0"

bindings/java/Makefile

@@ -0,0 +1,7 @@
+java_run: lib
+	export LIMBO_SYSTEM_PATH=../../target/debug && ./gradlew run
+
+.PHONY: lib
+
+lib:
+	cargo build

bindings/java/build.gradle.kts

@@ -0,0 +1,31 @@
+plugins {
+    java
+    application
+}
+
+group = "org.github.tursodatabase"
+version = "0.0.1-SNAPSHOT"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation(platform("org.junit:junit-bom:5.10.0"))
+    testImplementation("org.junit.jupiter:junit-jupiter")
+}
+
+application {
+    mainClass.set("org.github.tursodatabase.Main")
+
+    val limboSystemLibraryPath = System.getenv("LIMBO_SYSTEM_PATH")
+    if (limboSystemLibraryPath != null) {
+        applicationDefaultJvmArgs = listOf(
+            "-Djava.library.path=${System.getProperty("java.library.path")}:$limboSystemLibraryPath"
+        )
+    }
+}
+
+tasks.test {
+    useJUnitPlatform()
+}

bindings/java/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists