Another attempt using an agent

jpype/_core.py

@@ -237,6 +237,11 @@ def startJVM(
     if classpath:
         extra_jvm_args += (f'-Djava.class.path={_handleClassPath(classpath)}', )
 
+    supportLib = os.path.join(os.path.dirname(os.path.dirname(__file__)),"org.jpype.jar")
+    if not os.path.exists(supportLib):
+        raise RuntimeError("Unable to find org.jpype.jar support library at "+supportLib)
+    extra_jvm_args += ('-javaagent:'+supportLib,)
+
     try:
         import locale
         # Gather a list of locale settings that Java may override (excluding LC_ALL)

native/common/jp_classloader.cpp

@@ -17,29 +17,13 @@
 #include <jpype.h>
 #include <pyjp.h>
 #include <jp_classloader.h>
+#include <filesystem>
 
 jobject JPClassLoader::getBootLoader()
 {
 	return m_BootLoader.get();
 }
 
-static jobject toURL(JPJavaFrame &frame, const string& path)
-{
-	//  file = new File("org.jpype.jar");
-	jclass fileClass = frame.FindClass("java/io/File");
-	jmethodID newFile = frame.GetMethodID(fileClass, "<init>", "(Ljava/lang/String;)V");
-	jvalue v[3];
-	v[0].l = frame.NewStringUTF(path.c_str());
-	jobject file = frame.NewObjectA(fileClass, newFile, v);
-
-	// url = file.toURI().toURL();
-	jmethodID toURI = frame.GetMethodID(fileClass, "toURI", "()Ljava/net/URI;");
-	jobject uri = frame.CallObjectMethodA(file, toURI, nullptr);
-	jclass uriClass = frame.GetObjectClass(uri);
-	jmethodID toURL = frame.GetMethodID(uriClass, "toURL", "()Ljava/net/URL;");
-	return frame.CallObjectMethodA(uri, toURL, nullptr);
-}
-
 JPClassLoader::JPClassLoader(JPJavaFrame& frame)
 {
 	JP_TRACE_IN("JPClassLoader::JPClassLoader");
@@ -68,44 +52,8 @@ JPClassLoader::JPClassLoader(JPJavaFrame& frame)
 	}
 	frame.ExceptionClear();
 
-	// Harder, we need to find the _jpype module and use __file__ to obtain a
-	// path.
-	JPPyObject pypath = JPPyObject::call(PyObject_GetAttrString(PyJPModule, "__file__"));
-	string path = JPPyString::asStringUTF8(pypath.get());
-	string::size_type i = path.find_last_of('\\');
-	if (i == string::npos)
-		i = path.find_last_of('/');
-	if (i == string::npos)
-		JP_RAISE(PyExc_RuntimeError, "Can't find jar path");
-	path = path.substr(0, i + 1);
-	jobject url1 = toURL(frame, path + "org.jpype.jar");
-	//	jobject url2 = toURL(frame, path + "lib/asm-8.0.1.jar");
-
-	// urlArray = new URL[]{url};
-	jclass urlClass = frame.GetObjectClass(url1);
-	jobjectArray urlArray = frame.NewObjectArray(1, urlClass, nullptr);
-	frame.SetObjectArrayElement(urlArray, 0, url1);
-	//	frame.SetObjectArrayElement(urlArray, 1, url2);
-
-	// cl = new URLClassLoader(urlArray);
-	jclass urlLoaderClass = frame.FindClass("java/net/URLClassLoader");
-	jmethodID newURLClassLoader = frame.GetMethodID(urlLoaderClass, "<init>", "([Ljava/net/URL;Ljava/lang/ClassLoader;)V");
-	jvalue v[3];
-	v[0].l = (jobject) urlArray;
-	v[1].l = (jobject) m_SystemClassLoader.get();
-	jobject cl = frame.NewObjectA(urlLoaderClass, newURLClassLoader, v);
-
-	// Class dycl = Class.forName("org.jpype.classloader.DynamicClassLoader", true, cl);
-	v[0].l = frame.NewStringUTF("org.jpype.classloader.DynamicClassLoader");
-	v[1].z = true;
-	v[2].l = cl;
-	auto dyClass = (jclass) frame.CallStaticObjectMethodA(m_ClassClass.get(), m_ForNameID, v);
-
-	// dycl.newInstance(systemClassLoader);
-	jmethodID newDyLoader = frame.GetMethodID(dyClass, "<init>", "(Ljava/lang/ClassLoader;)V");
-	v[0].l = cl;
-	m_BootLoader = JPObjectRef(frame, frame.NewObjectA(dyClass, newDyLoader, v));
-
+	// org.jpype was not loaded already so we can't proceed
+	JP_RAISE(PyExc_RuntimeError, "Can't find org.jpype.jar support library");
 	JP_TRACE_OUT;  // GCOVR_EXCL_LINE
 }
 

native/java/manifest.txt

@@ -0,0 +1,2 @@
+Manifest-Version: 1.0
+Premain-Class: org.jpype.agent.JPypeAgent

native/java/org/jpype/agent/JPypeAgent.java

@@ -0,0 +1,10 @@
+package org.jpype.agent;
+
+import java.lang.instrument.Instrumentation;
+
+public class JPypeAgent
+{
+      public static void premain(String agentArgs, Instrumentation inst) {
+        System.out.println("Start jpype");
+      }
+}

project/jpype_java/manifest.mf

@@ -0,0 +1,2 @@
+Manifest-Version: 1.0
+Premain-Class: org.jpype.agent.JPypeAgent

project/jpype_java/nbproject/project.properties

@@ -113,3 +113,4 @@ source.encoding=UTF-8
 src.java.dir=${file.reference.native-java}
 test.harness.dir=${file.reference.test-harness}
 test.src.dir=test
+manifest.file=manifest.mf

setupext/build_ext.py

@@ -315,8 +315,12 @@ def build_java_ext(self, ext):
             os.makedirs("build/classes", exist_ok=True)
             self.announce("  %s" % " ".join(cmd1), level=distutils.log.INFO)
             subprocess.check_call(cmd1)
+            manifest = None
             try:
                 for file in glob.iglob("native/java/**/*.*", recursive=True):
+                    if file.endswith("manifest.txt"):
+                        manifest = file
+                        continue
                     if file.endswith(".java") or os.path.isdir(file):
                         continue
                     p = os.path.join(build_dir, os.path.relpath(file, "native/java"))
@@ -326,7 +330,7 @@ def build_java_ext(self, ext):
                 print("FAIL", ex)
                 pass
             cmd3 = shlex.split(
-                '%s cvf "%s" -C "%s" .' % (jar, jarFile, build_dir))
+                    '%s cvfm "%s" "%s" -C "%s" .' % (jar, jarFile, manifest, build_dir))
             self.announce("  %s" % " ".join(cmd3), level=distutils.log.INFO)
             subprocess.check_call(cmd3)