Move jars download to client instead of build

rust/build/java.rs

@@ -1,10 +1,9 @@
-use std::{collections::HashSet, fs, path::PathBuf};
+use std::{fs, path::PathBuf};
 
-use j4rs::{JvmBuilder, LocalJarArtifact, MavenArtifact, MavenArtifactRepo, MavenSettings};
+use j4rs::{JvmBuilder, LocalJarArtifact, MavenArtifactRepo, MavenSettings};
 
 pub fn setup_java(base: PathBuf) {
     let resources = base.join("resources");
-    let jassets = resources.join("jassets");
     let deps = resources.join("deps");
 
     let mut java_path = base.clone();
@@ -17,82 +16,6 @@ pub fn setup_java(base: PathBuf) {
         .join("libs")
         .join("patchbukkit.jar");
 
-    let dependencies = [
-        ("com.google.guava", "guava", "33.3.1-jre"),
-        (
-            "net.md-5",
-            "bungeecord-chat",
-            "1.21-R0.2-deprecated+build.21",
-        ),
-        ("net.kyori", "adventure-text-logger-slf4j", "4.25.0"),
-        ("net.kyori", "adventure-text-minimessage", "4.25.0"),
-        ("net.kyori", "adventure-text-serializer-legacy", "4.25.0"),
-        ("net.kyori", "adventure-text-serializer-plain", "4.25.0"),
-        ("net.kyori", "adventure-text-serializer-json", "4.25.0"),
-        ("net.kyori", "adventure-api", "4.25.0"),
-        ("net.kyori", "adventure-key", "4.25.0"),
-        ("net.kyori", "adventure-text-serializer-commons", "4.25.0"),
-        ("net.kyori", "adventure-text-serializer-gson", "4.25.0"),
-        ("com.google.code.gson", "gson", "2.11.0"),
-        ("org.yaml", "snakeyaml", "2.2"),
-        ("org.joml", "joml", "1.10.8"),
-        ("it.unimi.dsi", "fastutil", "8.5.15"),
-        ("org.apache.logging.log4j", "log4j-api", "2.24.1"),
-        (
-            "org.apache.maven.resolver",
-            "maven-resolver-connector-basic",
-            "1.9.18",
-        ),
-        (
-            "org.apache.maven.resolver",
-            "maven-resolver-transport-http",
-            "1.9.18",
-        ),
-        ("org.apache.maven", "maven-resolver-provider", "3.9.6"),
-        ("org.apache.maven.resolver", "maven-resolver-impl", "1.9.18"),
-        ("org.slf4j", "jcl-over-slf4j", "1.7.36"),
-        (
-            "org.apache.maven.resolver",
-            "maven-resolver-named-locks",
-            "1.9.18",
-        ),
-        ("org.slf4j", "slf4j-api", "2.0.16"),
-        ("com.mojang", "brigadier", "1.3.10"),
-        ("org.jspecify", "jspecify", "1.0.0"),
-        ("com.google.guava", "failureaccess", "1.0.2"),
-        (
-            "com.google.guava",
-            "listenablefuture",
-            "9999.0-empty-to-avoid-conflict-with-guava",
-        ),
-        ("com.google.code.findbugs", "jsr305", "3.0.2"),
-        ("org.checkerframework", "checker-qual", "3.43.0"),
-        ("com.google.errorprone", "error_prone_annotations", "2.28.0"),
-        ("com.google.j2objc", "j2objc-annotations", "3.0.0"),
-        ("org.apache.maven", "maven-model-builder", "3.9.6"),
-        ("org.apache.maven", "maven-model", "3.9.6"),
-        ("org.apache.maven", "maven-repository-metadata", "3.9.6"),
-        ("org.apache.maven.resolver", "maven-resolver-spi", "1.9.18"),
-        ("org.apache.maven.resolver", "maven-resolver-util", "1.9.18"),
-        ("org.apache.maven.resolver", "maven-resolver-api", "1.9.18"),
-        ("org.apache.maven", "maven-artifact", "3.9.6"),
-        ("org.codehaus.plexus", "plexus-utils", "3.5.1"),
-        ("javax.inject", "javax.inject", "1"),
-        ("org.apache.httpcomponents", "httpclient", "4.5.14"),
-        ("org.apache.httpcomponents", "httpcore", "4.4.16"),
-        ("commons-codec", "commons-codec", "1.16.0"),
-        ("net.kyori", "examination-string", "1.3.0"),
-        ("net.kyori", "examination-api", "1.3.0"),
-        ("org.codehaus.plexus", "plexus-interpolation", "1.26"),
-        ("org.apache.maven", "maven-builder-support", "3.9.6"),
-        ("org.eclipse.sisu", "org.eclipse.sisu.inject", "0.9.0.M2"),
-        ("org.apache.commons", "commons-lang3", "3.12.0"),
-        ("net.kyori", "option", "1.1.0"),
-        // These are deps of patchbukkit itself
-        ("io.papermc.paper", "paper-api", "1.21.11-R0.1-SNAPSHOT"),
-        ("com.google.protobuf", "protobuf-java", "4.33.5"),
-    ];
-
     let jvm = JvmBuilder::new()
         .with_maven_settings(MavenSettings::new(vec![MavenArtifactRepo::from(
             "papermc::https://repo.papermc.io/repository/maven-public/",
@@ -103,40 +26,6 @@ pub fn setup_java(base: PathBuf) {
         .map_err(|err| format!("jvm failed to init: {err:?}"))
         .unwrap();
 
-    let expected: HashSet<String> = dependencies
-        .iter()
-        .map(|d| format!("{}-{}.jar", d.1, d.2))
-        .collect();
-
-    for entry in fs::read_dir(&jassets).unwrap() {
-        let entry = entry.unwrap();
-        let file_name = entry.file_name().to_string_lossy().into_owned();
-
-        if file_name.starts_with("j4rs-") {
-            continue;
-        }
-
-        if !expected.contains(&file_name) {
-            let remove_path = entry.path();
-            fs::remove_file(remove_path).unwrap();
-        }
-    }
-
-    if deps.exists() {
-        fs::remove_dir_all(&deps).unwrap();
-    }
-
-    for dep in dependencies {
-        let jar_path = jassets.join(format!("{}-{}.jar", dep.1, dep.2));
-        if !jar_path.exists() {
-            jvm.deploy_artifact(&MavenArtifact::from(format!(
-                "{}:{}:{}",
-                dep.0, dep.1, dep.2
-            )))
-            .unwrap();
-        }
-    }
-
     if !&patchbukkit_jar.exists() {
         panic!(
             "Failed to find patchbukkit.jar, build the java library first by running `gradle build` in the java directory!"

rust/src/commands/mod.rs

@@ -142,7 +142,7 @@ impl CommandExecutor for JavaCommandExecutor {
                 })
                 .await
                 .unwrap();
-            Ok(())
+            Ok(1)
         })
     }
 }

rust/src/java/resources.rs

@@ -5,36 +5,170 @@ use std::{
 };
 
 use anyhow::Result;
+use j4rs::{JvmBuilder, MavenArtifact, MavenArtifactRepo, MavenSettings};
 use rust_embed::Embed;
 
 #[derive(Embed)]
 #[folder = "resources/"]
 pub struct Resources;
 
-pub fn cleanup_stale_files(j4rs_folder: &PathBuf) {
+pub const DEPENDENCIES: &[(&str, &str, &str)] = &[
-    let allowed: HashSet<PathBuf> = Resources::iter()
+    ("com.google.guava", "guava", "33.3.1-jre"),
+    (
+        "net.md-5",
+        "bungeecord-chat",
+        "1.21-R0.2-deprecated+build.21",
+    ),
+    ("net.kyori", "adventure-text-logger-slf4j", "4.25.0"),
+    ("net.kyori", "adventure-text-minimessage", "4.25.0"),
+    ("net.kyori", "adventure-text-serializer-legacy", "4.25.0"),
+    ("net.kyori", "adventure-text-serializer-plain", "4.25.0"),
+    ("net.kyori", "adventure-text-serializer-json", "4.25.0"),
+    ("net.kyori", "adventure-api", "4.25.0"),
+    ("net.kyori", "adventure-key", "4.25.0"),
+    ("net.kyori", "adventure-text-serializer-commons", "4.25.0"),
+    ("net.kyori", "adventure-text-serializer-gson", "4.25.0"),
+    ("com.google.code.gson", "gson", "2.11.0"),
+    ("org.yaml", "snakeyaml", "2.2"),
+    ("org.joml", "joml", "1.10.8"),
+    ("it.unimi.dsi", "fastutil", "8.5.15"),
+    ("org.apache.logging.log4j", "log4j-api", "2.24.1"),
+    (
+        "org.apache.maven.resolver",
+        "maven-resolver-connector-basic",
+        "1.9.18",
+    ),
+    (
+        "org.apache.maven.resolver",
+        "maven-resolver-transport-http",
+        "1.9.18",
+    ),
+    ("org.apache.maven", "maven-resolver-provider", "3.9.6"),
+    ("org.apache.maven.resolver", "maven-resolver-impl", "1.9.18"),
+    ("org.slf4j", "jcl-over-slf4j", "1.7.36"),
+    (
+        "org.apache.maven.resolver",
+        "maven-resolver-named-locks",
+        "1.9.18",
+    ),
+    ("org.slf4j", "slf4j-api", "2.0.16"),
+    ("com.mojang", "brigadier", "1.3.10"),
+    ("org.jspecify", "jspecify", "1.0.0"),
+    ("com.google.guava", "failureaccess", "1.0.2"),
+    (
+        "com.google.guava",
+        "listenablefuture",
+        "9999.0-empty-to-avoid-conflict-with-guava",
+    ),
+    ("com.google.code.findbugs", "jsr305", "3.0.2"),
+    ("org.checkerframework", "checker-qual", "3.43.0"),
+    ("com.google.errorprone", "error_prone_annotations", "2.28.0"),
+    ("com.google.j2objc", "j2objc-annotations", "3.0.0"),
+    ("org.apache.maven", "maven-model-builder", "3.9.6"),
+    ("org.apache.maven", "maven-model", "3.9.6"),
+    ("org.apache.maven", "maven-repository-metadata", "3.9.6"),
+    ("org.apache.maven.resolver", "maven-resolver-spi", "1.9.18"),
+    ("org.apache.maven.resolver", "maven-resolver-util", "1.9.18"),
+    ("org.apache.maven.resolver", "maven-resolver-api", "1.9.18"),
+    ("org.apache.maven", "maven-artifact", "3.9.6"),
+    ("org.codehaus.plexus", "plexus-utils", "3.5.1"),
+    ("javax.inject", "javax.inject", "1"),
+    ("org.apache.httpcomponents", "httpclient", "4.5.14"),
+    ("org.apache.httpcomponents", "httpcore", "4.4.16"),
+    ("commons-codec", "commons-codec", "1.16.0"),
+    ("net.kyori", "examination-string", "1.3.0"),
+    ("net.kyori", "examination-api", "1.3.0"),
+    ("org.codehaus.plexus", "plexus-interpolation", "1.26"),
+    ("org.apache.maven", "maven-builder-support", "3.9.6"),
+    ("org.eclipse.sisu", "org.eclipse.sisu.inject", "0.9.0.M2"),
+    ("org.apache.commons", "commons-lang3", "3.12.0"),
+    ("net.kyori", "option", "1.1.0"),
+    // These are deps of patchbukkit itself
+    ("io.papermc.paper", "paper-api", "1.21.11-R0.1-SNAPSHOT"),
+    ("com.google.protobuf", "protobuf-java", "4.33.5"),
+];
+
+pub fn setup_j4rs(j4rs_folder: &Path) -> Result<()> {
+    sync_embedded_resources(j4rs_folder)?;
+    cleanup_stale_files(j4rs_folder);
+    resolve_maven_dependencies(j4rs_folder)?;
+
+    Ok(())
+}
+
+fn resolve_maven_dependencies(j4rs_folder: &Path) -> Result<()> {
+    let jassets = j4rs_folder.join("jassets");
+
+    // Check if all expected jars already exist
+    let all_present = DEPENDENCIES
+        .iter()
+        .all(|&(_, artifact, version)| jassets.join(format!("{artifact}-{version}.jar")).exists());
+
+    if all_present {
+        log::debug!("All Maven dependencies already present, skipping JVM init");
+        return Ok(());
+    }
+
+    log::info!("Some Maven dependencies missing, starting JVM to resolve...");
+
+    let jvm = JvmBuilder::new()
+        .with_maven_settings(MavenSettings::new(vec![MavenArtifactRepo::from(
+            "papermc::https://repo.papermc.io/repository/maven-public/",
+        )]))
+        .skip_setting_native_lib()
+        .with_base_path(j4rs_folder)
+        .build()
+        .map_err(|err| anyhow::anyhow!("JVM failed to init: {err:?}"))?;
+
+    for &(group, artifact, version) in DEPENDENCIES {
+        let jar_path = jassets.join(format!("{artifact}-{version}.jar"));
+        if !jar_path.exists() {
+            log::info!("Downloading Maven dependency: {group}:{artifact}:{version}");
+            jvm.deploy_artifact(&MavenArtifact::from(format!(
+                "{group}:{artifact}:{version}"
+            )))
+            .map_err(|err| {
+                anyhow::anyhow!("Failed to deploy {group}:{artifact}:{version}: {err:?}")
+            })?;
+        }
+    }
+
+    Ok(())
+}
+
+fn cleanup_stale_files(j4rs_folder: &Path) {
+    let embedded_paths: HashSet<PathBuf> = Resources::iter()
         .map(|p| PathBuf::from(p.to_string()))
         .collect();
 
+    let maven_jars: HashSet<String> = DEPENDENCIES
+        .iter()
+        .map(|d| format!("{}-{}.jar", d.1, d.2))
+        .collect();
+
     for entry in walkdir::WalkDir::new(j4rs_folder)
         .into_iter()
-        .filter_map(std::result::Result::ok)
+        .filter_map(|e| e.ok())
         .filter(|e| e.file_type().is_file())
     {
         let path = entry.path();
+        if let Ok(rel_path) = path.strip_prefix(j4rs_folder) {
+            // Skip Maven-managed jars — handled by cleanup_stale_maven_jars
+            if let Some(file_name) = path.file_name().and_then(|f| f.to_str())
+                && maven_jars.contains(file_name)
+            {
+                continue;
+            }
 
-        if let Ok(rel_path) = path.strip_prefix(j4rs_folder)
+            if !embedded_paths.contains(rel_path) {
-            && !allowed.contains(rel_path)
+                log::warn!("Removing stale embedded file: {}", rel_path.display());
-        {
+                let _ = fs::remove_file(path);
-            log::warn!("Removing stale j4rs file: {}", rel_path.display());
-            if let Err(e) = fs::remove_file(path) {
-                log::error!("Failed to remove stale file {}: {}", path.display(), e);
             }
         }
     }
 }
 
-pub fn sync_embedded_resources(j4rs_folder: &Path) -> Result<(), String> {
+pub fn sync_embedded_resources(j4rs_folder: &Path) -> Result<()> {
     for resource_path_str in Resources::iter() {
         let resource_path = j4rs_folder.join(resource_path_str.to_string());
         let resource = Resources::get(&resource_path_str).unwrap();
@@ -49,25 +183,23 @@ pub fn sync_embedded_resources(j4rs_folder: &Path) -> Result<(), String> {
     Ok(())
 }
 
-fn write_resource(path: &Path, data: &[u8]) -> Result<(), String> {
+fn write_resource(path: &Path, data: &[u8]) -> Result<()> {
     if let Some(parent) = path.parent() {
-        fs::create_dir_all(parent)
+        fs::create_dir_all(parent)?;
-            .map_err(|_| format!("Failed to create directory: {}", parent.display()))?;
     }
 
-    fs::write(path, data).map_err(|_| format!("Failed to write resource: {}", path.display()))?;
+    fs::write(path, data)?;
     Ok(())
 }
 
-fn update_resource_if_changed(path: &Path, new_data: &[u8]) -> Result<(), String> {
+fn update_resource_if_changed(path: &Path, new_data: &[u8]) -> Result<()> {
     // Quick check: If file sizes differ, it's definitely changed, TODO: use Hash ?
     let metadata = fs::metadata(path).ok();
     let size_matches = metadata.is_some_and(|m| m.len() == new_data.len() as u64);
 
-    if !size_matches || fs::read(path).map_err(|e| e.to_string())? != new_data {
+    if !size_matches || fs::read(path)? != new_data {
         log::debug!("Updating changed resource: {}", path.display());
-        fs::write(path, new_data)
+        fs::write(path, new_data)?;
-            .map_err(|_| format!("Failed to update resource: {}", path.display()))?;
     }
 
     Ok(())

rust/src/lib.rs

@@ -13,18 +13,18 @@ pub mod java;
 pub mod proto;
 
 use directories::setup_directories;
-use java::{
+use java::jar::discover_jar_files;
-    jar::discover_jar_files,
-    resources::{cleanup_stale_files, sync_embedded_resources},
-};
 use tokio::sync::{
     mpsc::{self, Receiver},
     oneshot,
 };
 
-use crate::java::jvm::{
+use crate::java::{
-    commands::{JvmCommand, LoadPluginResult},
+    jvm::{
-    worker::JvmWorker,
+        commands::{JvmCommand, LoadPluginResult},
+        worker::JvmWorker,
+    },
+    resources::setup_j4rs,
 };
 
 async fn on_load_inner(plugin: &PatchBukkitPlugin, server: Arc<Context>) -> Result<(), String> {
@@ -101,8 +101,7 @@ async fn on_load_inner(plugin: &PatchBukkitPlugin, server: Arc<Context>) -> Resu
     }
 
     // Manage embedded resources
-    cleanup_stale_files(&dirs.j4rs);
+    setup_j4rs(&dirs.j4rs).map_err(|e| format!("Failed to setup J4RS: {e}"))?;
-    sync_embedded_resources(&dirs.j4rs)?;
 
     {
         let (tx, rx) = oneshot::channel();