Remove FieldExposers, since GAE reflection works normally

Calling setAccessible() cross-package used to fail in
the custom security manager. It never shouldn have failed,
and now it works correctly (not sure when it was fixed) so
remove these trampolines.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=138549703

java/google/registry/model/AbstractFieldExposer.java

@@ -1,35 +0,0 @@
-// Copyright 2016 The Nomulus Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package google.registry.model;
-
-import java.lang.reflect.Field;
-
-/**
- * A helper that exposes package-private fields in this package for reflective lookup.
- *
- * <p>By adding a subclass of this to every package in the model, we can write generic code that can
- * access fields with package private access. The other alternative is to call
- * {@link Field#setAccessible} with {@code true} on any such Field objects, but that does not work
- * reliably in Google App Engine cross-package because of its custom security manager
- * implementation.
- */
-public abstract class AbstractFieldExposer {
-  public abstract Object getFieldValue(Object instance, Field field) throws IllegalAccessException;
-
-  public abstract void setFieldValue(Object instance, Field field, Object value)
-      throws IllegalAccessException;
-
-  public abstract void setAccessible(Field field);
-}

java/google/registry/model/BUILD

@@ -11,10 +11,7 @@ java_library(
         "*.java",
         "*/*.java",
         "*/*/*.java",
-    ]) + [
-        "FieldExposerRegistry.java",
-        ":field_exposers",
-    ],
+    ]),
     visibility = ["//visibility:public"],
     deps = [
         "//java/com/google/common/annotations",
@@ -42,57 +39,3 @@ java_library(
         "//java/google/registry/xml",
     ],
 )
-
-# Generate FieldExposer classes to work around AppEngine's security limitations.
-genrule(
-    name = "field_exposers",
-    srcs = ["generate_field_exposer.sh"],
-    outs = [
-        "FieldExposer.java",
-        "billing/FieldExposer.java",
-        "common/FieldExposer.java",
-        "contact/FieldExposer.java",
-        "dns/FieldExposer.java",
-        "domain/FieldExposer.java",
-        "domain/allocate/FieldExposer.java",
-        "domain/fee/FieldExposer.java",
-        "domain/fee06/FieldExposer.java",
-        "domain/fee11/FieldExposer.java",
-        "domain/fee12/FieldExposer.java",
-        "domain/flags/FieldExposer.java",
-        "domain/launch/FieldExposer.java",
-        "domain/rgp/FieldExposer.java",
-        "domain/secdns/FieldExposer.java",
-        "eppcommon/FieldExposer.java",
-        "eppinput/FieldExposer.java",
-        "eppoutput/FieldExposer.java",
-        "export/FieldExposer.java",
-        "host/FieldExposer.java",
-        "index/FieldExposer.java",
-        "mark/FieldExposer.java",
-        "ofy/FieldExposer.java",
-        "poll/FieldExposer.java",
-        "rde/FieldExposer.java",
-        "registrar/FieldExposer.java",
-        "registry/FieldExposer.java",
-        "registry/label/FieldExposer.java",
-        "reporting/FieldExposer.java",
-        "server/FieldExposer.java",
-        "smd/FieldExposer.java",
-        "tmch/FieldExposer.java",
-        "transfer/FieldExposer.java",
-        "translators/FieldExposer.java",
-    ],
-    cmd = "for FILE in $(OUTS); do\n" +
-          "  $(location generate_field_exposer.sh) $$FILE >> $$FILE\n" +
-          "done",
-)
-
-# Generate a registry of FieldExposers.
-genrule(
-    name = "field_exposer_registry",
-    srcs = [":field_exposers"],
-    outs = ["FieldExposerRegistry.java"],
-    cmd = "$(location generate_field_exposer_registry.sh) $(SRCS) >$@",
-    tools = ["generate_field_exposer_registry.sh"],
-)

java/google/registry/model/ModelUtils.java

@@ -14,7 +14,6 @@
 
 package google.registry.model;
 
-import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Predicates.instanceOf;
 import static com.google.common.base.Predicates.isNull;
 import static com.google.common.base.Predicates.or;
@@ -27,7 +26,6 @@ import static java.util.Arrays.asList;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;
-import com.google.common.base.Preconditions;
 import com.google.common.base.Predicate;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
@@ -36,7 +34,6 @@ import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedMap;
-import com.google.common.collect.Maps;
 import com.google.common.collect.Ordering;
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Id;
@@ -74,35 +71,17 @@ public class ModelUtils {
             }
             Map<String, Field> fields = new LinkedHashMap<>();
             for (Class<?> hierarchyClass : hierarchy) {
-              Package pakkage = hierarchyClass.getPackage();
               // Don't use hierarchyClass.getFields() because it only picks up public fields.
               for (Field field : hierarchyClass.getDeclaredFields()) {
-                if (Modifier.isStatic(field.getModifiers())) {
-                  continue;
+                if (!Modifier.isStatic(field.getModifiers())) {
+                  field.setAccessible(true);
+                  fields.put(field.getName(), field);
                 }
-                // Strictly speaking this shouldn't be necessary since all of these fields
-                // are already accessible to their FieldExposer, but it is more performant
-                // to access fields if they are marked accessible this way because it skips
-                // various security checks.
-                checkNotNull(
-                    FIELD_EXPOSERS.get(pakkage),
-                    "No FieldExposer registered for %s", pakkage.getName())
-                        .setAccessible(field);
-                fields.put(field.getName(), field);
               }
             }
             return ImmutableMap.copyOf(fields);
           }});
 
-  /** Per-package trampolines to expose package-private fields for reflection. */
-  private static final Map<Package, AbstractFieldExposer> FIELD_EXPOSERS = Maps.uniqueIndex(
-      FieldExposerRegistry.getFieldExposers(),
-      new Function<AbstractFieldExposer, Package>() {
-        @Override
-        public Package apply(AbstractFieldExposer exposer) {
-          return exposer.getClass().getPackage();
-        }});
-
   /** Lists all instance fields on an object, including non-public and inherited fields. */
   static Map<String, Field> getAllFields(Class<?> clazz) {
     return ALL_FIELDS_CACHE.getUnchecked(clazz);
@@ -187,10 +166,7 @@ public class ModelUtils {
   /** Retrieves a field value via reflection. */
   static Object getFieldValue(Object instance, Field field) {
     try {
-      return Preconditions.checkNotNull(
-          FIELD_EXPOSERS.get(field.getDeclaringClass().getPackage()),
-          "No FieldExposer registered for %s", field.getDeclaringClass().getPackage().getName())
-              .getFieldValue(instance, field);
+      return field.get(instance);
     } catch (IllegalAccessException e) {
       throw new IllegalStateException(e);
     }
@@ -199,10 +175,7 @@ public class ModelUtils {
   /** Sets a field value via reflection. */
   static void setFieldValue(Object instance, Field field, Object value) {
     try {
-      Preconditions.checkNotNull(
-          FIELD_EXPOSERS.get(field.getDeclaringClass().getPackage()),
-          "No FieldExposer registered for %s", field.getDeclaringClass().getPackage().getName())
-              .setFieldValue(instance, field, value);
+      field.set(instance, value);
     } catch (IllegalAccessException e) {
       throw new IllegalStateException(e);
     }

java/google/registry/model/generate_field_exposer.sh

@@ -1,36 +0,0 @@
-#!/bin/sh -
-# Copyright 2016 The Nomulus Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-
-# Generate a FieldExposer for a given package
-
-printf "package google.registry.model"\
-`echo $1 | sed -e 's/.*\/model\(.*\).FieldExposer\.java/\1/' -e 's/\//./g'`";\
-\n\n\
-import google.registry.model.AbstractFieldExposer;\n\n\
-import java.lang.reflect.Field;\n\n\
-/** A helper that exposes package-private fields in this package for reflective lookup. */\n\
-public class FieldExposer extends AbstractFieldExposer {\n\
-  public Object getFieldValue(Object instance, Field field) throws IllegalAccessException {\n\
-    return field.get(instance);\n\
-  }\n\n\
-  public void setFieldValue(Object instance, Field field, Object value)\n\
-      throws IllegalAccessException {\n\
-    field.set(instance, value);\n\
-  }\n\n\
-  public void setAccessible(Field field) {\n\
-    field.setAccessible(true);\n\
-  }\n\
-}\n"

java/google/registry/model/generate_field_exposer_registry.sh

@@ -1,32 +0,0 @@
-#!/bin/sh -
-# Copyright 2016 The Nomulus Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-
-# Generate a FieldExposer for a given package
-
-printf "package google.registry.model;\n\n\
-import google.registry.model.AbstractFieldExposer;\n\n\
-import com.google.common.collect.ImmutableList;\n\n\
-/** A registry of all {@link AbstractFieldExposer} impls. */\n\
-class FieldExposerRegistry {\n\
-  static ImmutableList<AbstractFieldExposer> getFieldExposers() {\n\
-    return new ImmutableList.Builder<AbstractFieldExposer>()\n"
-for FILE in $@; do
-  echo $FILE | sed \
-      -e 's!^.*/java/\(.*\)\.java$!        .add(new \1())!' \
-      -e 's!/!.!g'
-done
-printf "        .build();\n"
-printf "  }\n}\n"