For now don't use the generated field accessors unless we're running in a

sandbox. They should work exactly the same but there seem to be remaining
niggles, so we'll iron those out without impacting other projects.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4706 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/io/FieldMarshaller.java

@@ -23,6 +23,7 @@ package com.threerings.io;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.ReflectPermission;
 
 import java.util.Date;
 import java.util.HashMap;
@@ -57,7 +58,8 @@ public abstract class FieldMarshaller
             createMarshallers();
         }
 
-        // first look to see if this field has custom reader/writer methods
+        // if necessary (we're running in a sandbox), look for custom field accessors
+        if (useFieldAccessors()) {
             Method reader = null, writer = null;
             try {
                 reader = field.getDeclaringClass().getMethod(
@@ -75,6 +77,7 @@ public abstract class FieldMarshaller
                             ", writer=" + writer + "].");
                 // fall through to using reflection on the fields...
             }
+        }
 
         Class ftype = field.getType();
         if (ftype.isInterface()) {
@@ -111,6 +114,23 @@ public abstract class FieldMarshaller
         return "writeField_" + field;
     }
 
+    /**
+     * Returns true if we should use the generated field marshaller methods that allow us to work
+     * around our inability to read and write protected and private fields of a {@link Streamable}.
+     */
+    protected static boolean useFieldAccessors ()
+    {
+        try {
+            SecurityManager security = System.getSecurityManager();
+            if (security != null) {
+                security.checkPermission(new ReflectPermission("suppressAccessChecks"));
+            }
+            return false;
+        } catch (SecurityException se) {
+            return true;
+        }
+    }
+
     /**
      * Used to marshall and unmarshall classes for which we have a basic {@link Streamer}.
      */
@@ -157,7 +177,7 @@ public abstract class FieldMarshaller
     }
 
     /**
-     * Uses custom reader and writer methods to read and write a field.
+     * Uses custom accessor methods to read and write a field.
      */
     protected static class MethodFieldMarshaller extends FieldMarshaller
     {