Fix custom class loader registry lookups

java_runtime/src/classes/java/lang/class_loader.rs

@@ -186,9 +186,10 @@ impl ClassLoader {
         }
 
         let name_str = JavaLangString::to_rust_string(jvm, &name).await?;
+        let internal_name = name_str.replace('.', "/");
 
-        if let Some(element_type_name) = name_str.strip_prefix('[') {
-            let ultimate_element_type = element_type_name.trim_start_matches('[');
+        if let Some(element_type_name) = internal_name.strip_prefix('[') {
+            let ultimate_element_type = name_str.trim_start_matches('[');
             let defining_loader = if let Some(element_class_name) = ultimate_element_type.strip_prefix('L').and_then(|name| name.strip_suffix(';')) {
                 let element_class_name = JavaLangString::from_rust_string(jvm, element_class_name).await?;
                 let element_class: ClassInstanceRef<Class> = jvm
@@ -210,7 +211,7 @@ impl ClassLoader {
             jvm.invoke_virtual(&parent, "loadClass", "(Ljava/lang/String;)Ljava/lang/Class;", (name.clone(),))
                 .await?
         } else {
-            jvm.load_bootstrap_class(&name_str).await?.into()
+            jvm.load_bootstrap_class(&internal_name).await?.into()
         };
 
         if !class.is_null() {
@@ -243,12 +244,12 @@ impl ClassLoader {
     ) -> Result<ClassInstanceRef<Class>> {
         tracing::debug!("java.lang.ClassLoader::findLoadedClass({this:?}, {name:?})");
 
-        let rust_name = JavaLangString::to_rust_string(jvm, &name).await?;
-        if !jvm.has_class(&rust_name) {
+        let internal_name = JavaLangString::to_rust_string(jvm, &name).await?.replace('.', "/");
+        if !jvm.has_class(&internal_name) {
             return Ok(None.into());
         }
 
-        let class = jvm.resolve_class(&rust_name).await?;
+        let class = jvm.resolve_class(&internal_name).await?;
 
         Ok(class.java_class().into())
     }

jvm/src/runtime/java_lang_class_loader.rs

@@ -17,7 +17,8 @@ impl JavaLangClassLoader {
 
     #[allow(clippy::borrowed_box)]
     pub async fn load_class(jvm: &Jvm, this: &Box<dyn ClassInstance>, class_name: &str) -> Result<Option<Box<dyn ClassInstance>>> {
-        let java_class_name = JavaLangString::from_rust_string(jvm, class_name).await?;
+        let binary_name = class_name.replace('/', ".");
+        let java_class_name = JavaLangString::from_rust_string(jvm, &binary_name).await?;
 
         let java_class: Option<Box<dyn ClassInstance>> = jvm
             .invoke_virtual(this, "loadClass", "(Ljava/lang/String;)Ljava/lang/Class;", (java_class_name,))

test_data/ClassMetadata.txt

@@ -23,3 +23,7 @@ true
 true
 true
 true
+true
+true
+true
+true

test_data/src/ClassMetadata.java

@@ -12,12 +12,14 @@ static class Payload {
     }
 
     static class ByteLoader extends ClassLoader {
+        int findCount;
+
         ByteLoader(ClassLoader parent) {
             super(parent);
         }
 
         public Class loadClass(String name) throws ClassNotFoundException {
-            if (!name.equals("ClassMetadata$Payload")) {
+            if (!name.equals("ClassMetadata$Payload") && !name.startsWith("loader.")) {
                 return super.loadClass(name);
             }
 
@@ -27,7 +29,16 @@ public Class loadClass(String name) throws ClassNotFoundException {
 
         protected Class findClass(String name) throws ClassNotFoundException {
             try {
-                java.io.InputStream input = ClassMetadata.class.getResourceAsStream("ClassMetadata$Payload.class");
+                findCount++;
+                String resourceName;
+                if (name.equals("ClassMetadata$Payload")) {
+                    resourceName = "ClassMetadata$Payload.class";
+                } else if (name.equals("loader.Payload")) {
+                    resourceName = "loader/Payload.class";
+                } else {
+                    resourceName = "loader/Base.class";
+                }
+                java.io.InputStream input = ClassMetadata.class.getResourceAsStream(resourceName);
                 byte[] bytes = new byte[input.available()];
                 int offset = 0;
                 while (offset < bytes.length) {
@@ -84,5 +95,14 @@ public static void main(String[] args) throws Exception {
         System.out.println(payloadMatrix.getClassLoader() == customLoader);
         System.out.println(payloadArray.getComponentType() == payload);
         System.out.println(payloadMatrix.getComponentType() == payloadArray);
+
+        Class packagedPayload = customLoader.loadClass("loader.Payload");
+        Class packagedPayloadAgain = customLoader.loadClass("loader.Payload");
+        Class packagedPayloadArray = customLoader.loadClass("[Lloader.Payload;");
+        Class packagedPayloadArrayAgain = customLoader.loadClass("[Lloader.Payload;");
+        System.out.println(packagedPayload == packagedPayloadAgain);
+        System.out.println(packagedPayloadArray == packagedPayloadArrayAgain);
+        System.out.println(packagedPayload.getSuperclass().getClassLoader() == customLoader);
+        System.out.println(customLoader.findCount == 3);
     }
 }

test_data/src/loader/Base.java

@@ -0,0 +1,4 @@
+package loader;
+
+public class Base {
+}

test_data/src/loader/Payload.java

@@ -0,0 +1,4 @@
+package loader;
+
+public class Payload extends Base {
+}