Jigsaw support: As we already load the class from Jigsaw as Class<?> …

…instance, we don't need InputStream of bytecode. Just use reflective analysis to get methods and fields!

src/main/java/de/thetaphi/forbiddenapis/Checker.java

@@ -70,7 +70,7 @@ public static enum Option {
   final Logger logger;
 
   final ClassLoader loader;
-  final java.lang.reflect.Method method_Class_getModule, method_Module_getResourceAsStream, method_Module_getName;
+  final java.lang.reflect.Method method_Class_getModule, method_Module_getName;
   final EnumSet<Option> options;
 
   // key is the binary name (dotted):
@@ -131,19 +131,16 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
 
     // first try Java 9 module system (Jigsaw)
     // Please note: This code is not guaranteed to work with final Java 9 version. This is just for testing!
-    java.lang.reflect.Method method_Class_getModule, method_Module_getResourceAsStream, method_Module_getName;
+    java.lang.reflect.Method method_Class_getModule, method_Module_getName;
     try {
       method_Class_getModule = Class.class.getMethod("getModule");
-      method_Module_getResourceAsStream = method_Class_getModule
-          .getReturnType().getMethod("getResourceAsStream", String.class);
       method_Module_getName = method_Class_getModule
           .getReturnType().getMethod("getName");
       isSupportedJDK = true;
     } catch (NoSuchMethodException e) {
-      method_Class_getModule = method_Module_getResourceAsStream = method_Module_getName = null;
+      method_Class_getModule = method_Module_getName = null;
     }
     this.method_Class_getModule = method_Class_getModule;
-    this.method_Module_getResourceAsStream = method_Module_getResourceAsStream;
     this.method_Module_getName = method_Module_getName;
 
     final NavigableSet<String> runtimePaths = new TreeSet<String>();
@@ -208,7 +205,7 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
         logger.warn("Bundled version of ASM cannot parse bytecode of java.lang.Object class; marking runtime as not suppported.");
         isSupportedJDK = false;
       } catch (ClassNotFoundException cnfe) {
-        logger.warn("Bytecode of java.lang.Object not found; marking runtime as not suppported.");
+        logger.warn("Bytecode or Class<?> instance of java.lang.Object not found; marking runtime as not suppported.");
         isSupportedJDK = false;
       } catch (IOException ioe) {
         logger.warn("IOException while loading java.lang.Object class from classloader; marking runtime as not suppported: " + ioe);
@@ -226,29 +223,21 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
    * This is just for testing!
    **/
   private ClassSignature loadClassFromJigsaw(String classname) throws IOException {
-    if (method_Class_getModule == null || method_Module_getResourceAsStream == null || method_Module_getName == null) {
+    if (method_Class_getModule == null || method_Module_getName == null) {
       return null; // not Java 9 JIGSAW
     }
 
-    final InputStream in;
+    final Class<?> clazz;
     final String moduleName;
     try {
-      final Class<?> clazz = Class.forName(classname, false, loader);
+      clazz = Class.forName(classname, false, loader);
       final Object module = method_Class_getModule.invoke(clazz);
       moduleName = (String) method_Module_getName.invoke(module);
-      in = (InputStream) method_Module_getResourceAsStream.invoke(module, AsmUtils.getClassResourceName(classname));
-      if (in == null) {
-        return null;
-      }
     } catch (Exception e) {
       return null; // not found
     }
 
-    try {
-      return new ClassSignature(AsmUtils.readAndPatchClass(in), AsmUtils.isRuntimeModule(moduleName), false);
-    } finally {
-      in.close();
-    }
+    return new ClassSignature(clazz, AsmUtils.isRuntimeModule(moduleName));
   }
 
   private boolean isRuntimePath(URL url) throws IOException {

src/main/java/de/thetaphi/forbiddenapis/ClassSignature.java

@@ -41,6 +41,7 @@ final class ClassSignature {
 	public final String className, superName;
 	public final String[] interfaces;
 
+	/** Builds the information from an ASM ClassReader */
   public ClassSignature(final ClassReader classReader, boolean isRuntimeClass, boolean withReader) {
     this.reader = withReader ? classReader : null;
     this.isRuntimeClass = isRuntimeClass;
@@ -67,6 +68,33 @@ public FieldVisitor visitField(int access, String name, String desc, String sign
     this.fields = Collections.unmodifiableSet(fields);
   }
 
+  /** Alternative ctor that can be used to build the information via reflection from an already loaded class. Useful for Java 9 Jigsaw. */
+  public ClassSignature(final Class<?> clazz, boolean isRuntimeClass) {
+    this.reader = null; // no reader available!
+    this.isRuntimeClass = isRuntimeClass;
+    this.className = Type.getType(clazz).getInternalName();
+    final Class<?> superclazz = clazz.getSuperclass();
+    this.superName = superclazz == null ? null : Type.getType(superclazz).getInternalName();
+    final Class<?>[] interfClasses = clazz.getInterfaces();
+    this.interfaces = new String[interfClasses.length];
+    for (int i = 0; i < interfClasses.length; i++) {
+      this.interfaces[i] = Type.getType(interfClasses[i]).getInternalName();
+    }
+    final Set<Method> methods = new HashSet<Method>();
+    final Set<String> fields = new HashSet<String>();
+    for (final java.lang.reflect.Method m : clazz.getDeclaredMethods()) {
+      methods.add(Method.getMethod(m));
+    }
+    for (final java.lang.reflect.Constructor<?> m : clazz.getDeclaredConstructors()) {
+      methods.add(Method.getMethod(m));
+    }
+    for (final java.lang.reflect.Field f : clazz.getDeclaredFields()) {
+      fields.add(f.getName());
+    }
+    this.methods = Collections.unmodifiableSet(methods);
+    this.fields = Collections.unmodifiableSet(fields);
+  }
+
   public ClassReader getReader() {
     if (reader == null)
       throw new IllegalStateException("'" + Type.getObjectType(className).getClassName() + "' has no ClassReader, because it was already checked or is only loaded as related class.");