Java example source code file (AbstractBindingBuilder.java)

This example Java source code file (AbstractBindingBuilder.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

abstractbindingbuilder, annotation, binder, bindingimpl, class, constant, constant_value_already_set, implementation_already_set, instancebinding, key, list, more, scope, string, untargettedbindingimpl, util

The AbstractBindingBuilder.java Java example source code

/**
 * Copyright (C) 2008 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.internal;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.inject.Binder;
import com.google.inject.Key;
import com.google.inject.Scope;
import com.google.inject.spi.Element;
import com.google.inject.spi.InstanceBinding;

import java.lang.annotation.Annotation;
import java.util.List;

/**
 * Bind a value or constant.
 *
 * @author jessewilson@google.com (Jesse Wilson)
 */
public abstract class AbstractBindingBuilder<T> {

  public static final String IMPLEMENTATION_ALREADY_SET = "Implementation is set more than once.";
  public static final String SINGLE_INSTANCE_AND_SCOPE
      = "Setting the scope is not permitted when binding to a single instance.";
  public static final String SCOPE_ALREADY_SET = "Scope is set more than once.";
  public static final String BINDING_TO_NULL = "Binding to null instances is not allowed. "
      + "Use toProvider(Providers.of(null)) if this is your intended behaviour.";
  public static final String CONSTANT_VALUE_ALREADY_SET = "Constant value is set more than once.";
  public static final String ANNOTATION_ALREADY_SPECIFIED
      = "More than one annotation is specified for this binding.";

  protected static final Key<?> NULL_KEY = Key.get(Void.class);

  protected List<Element> elements;
  protected int position;
  protected final Binder binder;
  private BindingImpl<T> binding;

  public AbstractBindingBuilder(Binder binder, List<Element> elements, Object source, Key key) {
    this.binder = binder;
    this.elements = elements;
    this.position = elements.size();
    this.binding = new UntargettedBindingImpl<T>(source, key, Scoping.UNSCOPED);
    elements.add(position, this.binding);
  }

  protected BindingImpl<T> getBinding() {
    return binding;
  }

  protected BindingImpl<T> setBinding(BindingImpl binding) {
    this.binding = binding;
    elements.set(position, binding);
    return binding;
  }

  /** Sets the binding to a copy with the specified annotation on the bound key */
  protected BindingImpl<T> annotatedWithInternal(Class annotationType) {
    checkNotNull(annotationType, "annotationType");
    checkNotAnnotated();
    return setBinding(binding.withKey(
        Key.get(this.binding.getKey().getTypeLiteral(), annotationType)));
  }

  /** Sets the binding to a copy with the specified annotation on the bound key */
  protected BindingImpl<T> annotatedWithInternal(Annotation annotation) {
    checkNotNull(annotation, "annotation");
    checkNotAnnotated();
    return setBinding(binding.withKey(
        Key.get(this.binding.getKey().getTypeLiteral(), annotation)));
  }

  public void in(final Class<? extends Annotation> scopeAnnotation) {
    checkNotNull(scopeAnnotation, "scopeAnnotation");
    checkNotScoped();
    setBinding(getBinding().withScoping(Scoping.forAnnotation(scopeAnnotation)));
  }

  public void in(final Scope scope) {
    checkNotNull(scope, "scope");
    checkNotScoped();
    setBinding(getBinding().withScoping(Scoping.forInstance(scope)));
  }

  public void asEagerSingleton() {
    checkNotScoped();
    setBinding(getBinding().withScoping(Scoping.EAGER_SINGLETON));
  }

  protected boolean keyTypeIsSet() {
    return !Void.class.equals(binding.getKey().getTypeLiteral().getType());
  }

  protected void checkNotTargetted() {
    if (!(binding instanceof UntargettedBindingImpl)) {
      binder.addError(IMPLEMENTATION_ALREADY_SET);
    }
  }

  protected void checkNotAnnotated() {
    if (binding.getKey().getAnnotationType() != null) {
      binder.addError(ANNOTATION_ALREADY_SPECIFIED);
    }
  }

  protected void checkNotScoped() {
    // Scoping isn't allowed when we have only one instance.
    if (binding instanceof InstanceBinding) {
      binder.addError(SINGLE_INSTANCE_AND_SCOPE);
      return;
    }

    if (binding.getScoping().isExplicitlyScoped()) {
      binder.addError(SCOPE_ALREADY_SET);
    }
  }
}