src/com/google/inject/InternalFactoryToProviderAdapter.java

/**
 * Copyright (C) 2006 Google Inc.
 *
 * 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.inject;

import static com.google.common.base.Preconditions.checkNotNull;
import com.google.inject.internal.Errors;
import com.google.inject.internal.ErrorsException;
import com.google.inject.spi.InjectionPoint;
import com.google.inject.spi.SourceProviders;

/**
 * @author crazybob@google.com (Bob Lee)
*/
class InternalFactoryToProviderAdapter<T> implements InternalFactory<T> {

  private final Provider<? extends T> provider;
  private final Object source;

  public InternalFactoryToProviderAdapter(Provider<? extends T> provider) {
    this(provider, SourceProviders.UNKNOWN_SOURCE);
  }

  public InternalFactoryToProviderAdapter(
      Provider<? extends T> provider, Object source) {
    this.provider = checkNotNull(provider, "provider");
    this.source = checkNotNull(source, "source");
  }

  public T get(Errors errors, InternalContext context, InjectionPoint<?> injectionPoint)
      throws ErrorsException {
    try {
      context.ensureMemberInjected(errors, provider);
      T result = provider.get();
      return injectionPoint.checkForNull(errors, result, source);
    } catch (RuntimeException userException) {
      Errors userErrors = ProvisionException.getErrors(userException);
      throw errors.errorInProvider(userException, userErrors).toException();
    }
  }

  @Override public String toString() {
    return provider.toString();
  }
}