mv com/google/domain/registry google/registry

This change renames directories in preparation for the great package
rename. The repository is now in a broken state because the code
itself hasn't been updated. However this should ensure that git
correctly preserves history for each file.

javatests/google/registry/testing/SystemPropertyRule.java

@@ -0,0 +1,97 @@
+// Copyright 2016 The Domain Registry 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 com.google.domain.registry.testing;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.base.Optional;
+
+import org.junit.rules.ExternalResource;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.annotation.Nullable;
+
+/**
+ * JUnit Rule for overriding the values Java system properties during tests.
+ */
+public final class SystemPropertyRule extends ExternalResource {
+
+  /** Class representing a system property key value pair. */
+  private static class Property {
+    final String key;
+    final Optional<String> value;
+
+    Property(String key, Optional<String> value) {
+      this.key = checkNotNull(key, "key");
+      this.value = checkNotNull(value, "value");
+    }
+
+    void set() {
+      if (value.isPresent()) {
+        System.setProperty(key, value.get());
+      } else {
+        System.clearProperty(key);
+      }
+    }
+  }
+
+  private boolean isRunning = false;
+  private final List<Property> pendings = new ArrayList<>();
+  private final Map<String, Property> originals = new HashMap<>();
+
+  /**
+   * Change the value of a system property which is restored to its original value after the test.
+   *
+   * <p>It's safe to call this method multiple times with the same {@code key} within a single
+   * test. Only the truly original property value will be restored at the end.
+   *
+   * <p>This method can be called fluently when declaring the Rule field, or within a Test method.
+   *
+   * @see java.lang.System#setProperty(String, String)
+   */
+  public SystemPropertyRule override(String key, @Nullable String value) {
+    if (!originals.containsKey(key)) {
+      originals.put(key, new Property(key, Optional.fromNullable(System.getProperty(key))));
+    }
+    Property property = new Property(key, Optional.fromNullable(value));
+    if (isRunning) {
+      property.set();
+    } else {
+      pendings.add(property);
+    }
+    return this;
+  }
+
+  @Override
+  protected void before() throws Exception {
+    checkState(!isRunning);
+    for (Property pending : pendings) {
+      pending.set();
+    }
+    isRunning = true;
+  }
+
+  @Override
+  protected void after() {
+    for (Property original : originals.values()) {
+      original.set();
+    }
+  }
+}