1 files changed, 103 insertions, 0 deletions
diff --git a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java
new file mode 100644
index 00000000000..9abf573c73a
--- /dev/null
+++ b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java
@@ -0,0 +1,103 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey;
+
+import org.objectweb.asm.AnnotationVisitor;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+
+import javax.ws.rs.Path;
+import javax.ws.rs.ext.Provider;
+
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * @author Tony Vaagenes
+ * @author ollivir
+ */
+public class ResourceOrProviderClassVisitor extends ClassVisitor {
+    private String className = null;
+    private boolean isPublic = false;
+    private boolean isAbstract = false;
+
+    private boolean isInnerClass = false;
+    private boolean isStatic = false;
+
+    private boolean isAnnotated = false;
+
+    public ResourceOrProviderClassVisitor() {
+        super(Opcodes.ASM5);
+    }
+
+    public Optional<String> getJerseyClassName() {
+        if (isJerseyClass()) {
+            return Optional.of(getClassName());
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    public boolean isJerseyClass() {
+        return isAnnotated && isPublic && !isAbstract && (!isInnerClass || isStatic);
+    }
+
+    public String getClassName() {
+        assert (className != null);
+        return org.objectweb.asm.Type.getObjectType(className).getClassName();
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+        isPublic = isPublic(access);
+        className = name;
+        isAbstract = isAbstract(access);
+    }
+
+    @Override
+    public void visitInnerClass(String name, String outerName, String innerName, int access) {
+        assert (className != null);
+
+        if (name.equals(className)) {
+            isInnerClass = true;
+            isStatic = isStatic(access);
+        }
+    }
+
+    @Override
+    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
+        isAnnotated |= annotationClassDescriptors.contains(desc);
+        return null;
+    }
+
+    private static Set<String> annotationClassDescriptors = new HashSet<>();
+
+    static {
+        annotationClassDescriptors.add(Type.getDescriptor(Path.class));
+        annotationClassDescriptors.add(Type.getDescriptor(Provider.class));
+    }
+
+    private static boolean isPublic(int access) {
+        return isSet(Opcodes.ACC_PUBLIC, access);
+    }
+
+    private static boolean isStatic(int access) {
+        return isSet(Opcodes.ACC_STATIC, access);
+    }
+
+    private static boolean isAbstract(int access) {
+        return isSet(Opcodes.ACC_ABSTRACT, access);
+    }
+
+    private static boolean isSet(int bits, int access) {
+        return (access & bits) == bits;
+    }
+
+    public static ResourceOrProviderClassVisitor visit(ClassReader classReader) {
+        ResourceOrProviderClassVisitor visitor = new ResourceOrProviderClassVisitor();
+        classReader.accept(visitor, ClassReader.SKIP_DEBUG | ClassReader.SKIP_CODE | ClassReader.SKIP_FRAMES);
+        return visitor;
+    }
+}