From: nickl- <github@jigsoft.co.za>
Date: Fri, 27 Oct 2017 04:43:49 +0000 (+0200)
Subject: Add getMethodHandle to SecurityActions.
X-Git-Tag: rel_3_23_0_ga~9^2~11
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=31b7faa0bc15d62d5c390096a02cebed344a620d;p=javassist.git

Add getMethodHandle to SecurityActions.

The main advantage is that we can do the privileged setAccessible during creation and
then freely invoke via the authorized method handle.

As per the javadocs:
Access checks are applied in the factory methods of Lookup, when a method handle is created.
his is a key difference from the Core Reflection API, since java.lang.reflect.Method.invoke
performs access checking against every caller, on every call.

The performance boost is just a bonus.
---

diff --git a/src/main/javassist/util/proxy/SecurityActions.java b/src/main/javassist/util/proxy/SecurityActions.java
index ed1ec981..272ccfec 100755
--- a/src/main/javassist/util/proxy/SecurityActions.java
+++ b/src/main/javassist/util/proxy/SecurityActions.java
@@ -15,6 +15,8 @@
  */
 package javassist.util.proxy;
 
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
 import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
@@ -51,8 +53,32 @@ class SecurityActions {
         }
     }
 
-    static Method getDeclaredMethod(final Class clazz, final String name,
-            final Class[] types) throws NoSuchMethodException {
+    static MethodHandle getMethodHandle(final Class<?> clazz, final
+                String name, final Class<?>[] params) throws NoSuchMethodException
+    {
+        try {
+            return AccessController.doPrivileged(
+                new PrivilegedExceptionAction<MethodHandle>() {
+                    public MethodHandle run() throws IllegalAccessException,
+                            NoSuchMethodException, SecurityException {
+                        Method rmet = clazz.getDeclaredMethod(name, params);
+                        rmet.setAccessible(true);
+                        MethodHandle meth = MethodHandles.lookup().unreflect(rmet);
+                        rmet.setAccessible(false);
+                        return meth;
+                    }
+                });
+        }
+        catch (PrivilegedActionException e) {
+            if (e.getCause() instanceof NoSuchMethodException)
+                throw (NoSuchMethodException) e.getCause();
+            throw new RuntimeException(e.getCause());
+        }
+    }
+
+    static Method getDeclaredMethod(final Class<?> clazz, final String name,
+            final Class<?>[] types) throws NoSuchMethodException
+    {
         if (System.getSecurityManager() == null)
             return clazz.getDeclaredMethod(name, types);
         else {