guava/src/com/google/common/primitives/Platform.java

/*
 * Copyright (C) 2019 The Guava Authors
 *
 * 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.common.primitives;

import com.google.common.annotations.GwtCompatible;

/** Methods factored out so that they can be emulated differently in GWT. */
@GwtCompatible(emulated = true)
final class Platform {
  private static final java.util.logging.Logger logger =
      java.util.logging.Logger.getLogger(Platform.class.getName());

  static void checkGwtRpcEnabled() {
    String propertyName = "guava.gwt.emergency_reenable_rpc";

    if (!Boolean.parseBoolean(System.getProperty(propertyName, "false"))) {
      throw new UnsupportedOperationException(
          com.google.common.base.Strings.lenientFormat(
              "We are removing GWT-RPC support for Guava types. You can temporarily reenable"
                  + " support by setting the system property %s to true. For more about system"
                  + " properties, see %s. For more about Guava's GWT-RPC support, see %s.",
              propertyName,
              "https://stackoverflow.com/q/5189914/28465",
              "https://groups.google.com/d/msg/guava-announce/zHZTFg7YF3o/rQNnwdHeEwAJ"));
    }
    logger.log(
        java.util.logging.Level.WARNING,
        "Later in 2020, we will remove GWT-RPC support for Guava types. You are seeing this"
            + " warning because you are sending a Guava type over GWT-RPC, which will break. You"
            + " can identify which type by looking at the class name in the attached stack trace.",
        new Throwable());

  }

  private Platform() {}
}