pkg/vm_service/java/src/org/dartlang/vm/service/internal/ErrorRequestSink.java

/*
 * Copyright (c) 2015, the Dart project authors.
 *
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 *
 * 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 org.dartlang.vm.service.internal;

import com.google.gson.JsonObject;
import org.dartlang.vm.service.logging.Logging;

/**
 * A {@link RequestSink} that reports with an error to each request.
 */
public class ErrorRequestSink implements RequestSink, VmServiceConst {
  /**
   * The {@link ResponseSink} to send error responses to.
   */
  private final ResponseSink responseSink;

  private final String code;
  private final String message;

  public ErrorRequestSink(ResponseSink responseSink, String code, String message) {
    if (responseSink == null || code == null || message == null) {
      throw new IllegalArgumentException("Unexpected null argument: " + responseSink + " "
          + code + " " + message);
    }
    this.responseSink = responseSink;
    this.code = code;
    this.message = message;
  }

  @Override
  public void add(JsonObject request) {
    String id = request.getAsJsonPrimitive(ID).getAsString();
    try {
      // TODO(danrubel) is this the correct format for an error response?
      JsonObject error = new JsonObject();
      error.addProperty(CODE, code);
      error.addProperty(MESSAGE, message);
      JsonObject response = new JsonObject();
      response.addProperty(ID, id);
      response.add(ERROR, error);
      responseSink.add(response);
    } catch (Throwable e) {
      Logging.getLogger().logError(e.getMessage(), e);
    }
  }

  @Override
  public void close() {
  }
}