Java example source code file (FactoryModuleBuilderTest.java)

This example Java source code file (FactoryModuleBuilderTest.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

abstractmodule, assistedinject, beetle, car, cat, color, creationexception, factorymodulebuilder, injector, mustang, named, override, string, suppresswarnings, util

The FactoryModuleBuilderTest.java Java example source code

/**
 * Copyright (C) 2009 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.assistedinject;

import static com.google.inject.Asserts.assertContains;
import static com.google.inject.name.Names.named;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.inject.AbstractModule;
import com.google.inject.Binding;
import com.google.inject.CreationException;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.Module;
import com.google.inject.Provides;
import com.google.inject.Singleton;
import com.google.inject.Stage;
import com.google.inject.TypeLiteral;
import com.google.inject.name.Named;
import com.google.inject.name.Names;
import com.google.inject.spi.Dependency;
import com.google.inject.spi.Element;
import com.google.inject.spi.Elements;
import com.google.inject.spi.HasDependencies;
import com.google.inject.spi.Message;

import junit.framework.TestCase;

import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class FactoryModuleBuilderTest extends TestCase {
  
  private enum Color { BLUE, GREEN, RED, GRAY, BLACK }

  public void testImplicitForwardingAssistedBindingFailsWithInterface() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          bind(Car.class).to(Golf.class);
          install(new FactoryModuleBuilder().build(ColoredCarFactory.class));
        }
      });
      fail();
    } catch (CreationException ce) {
      assertContains(
          ce.getMessage(), "1) " + Car.class.getName() + " is an interface, not a concrete class.",
          "Unable to create AssistedInject factory.",
          "while locating " + Car.class.getName(),
          "at " + ColoredCarFactory.class.getName() + ".create(");
      assertEquals(1, ce.getErrorMessages().size());
    }
  }
  
  public void testImplicitForwardingAssistedBindingFailsWithAbstractClass() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          bind(AbstractCar.class).to(ArtCar.class);
          install(new FactoryModuleBuilder().build(ColoredAbstractCarFactory.class));
        }
      });
      fail();
    } catch (CreationException ce) {
      assertContains(
          ce.getMessage(), "1) " + AbstractCar.class.getName() + " is abstract, not a concrete class.",
          "Unable to create AssistedInject factory.",
          "while locating " + AbstractCar.class.getName(),
          "at " + ColoredAbstractCarFactory.class.getName() + ".create(");
      assertEquals(1, ce.getErrorMessages().size());
    }
  }

  public void testImplicitForwardingAssistedBindingCreatesNewObjects() {
    final Mustang providedMustang = new Mustang(Color.BLUE);
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        install(new FactoryModuleBuilder().build(MustangFactory.class));
      }
      @Provides Mustang provide() { return providedMustang; }
    });
    assertSame(providedMustang, injector.getInstance(Mustang.class));
    MustangFactory factory = injector.getInstance(MustangFactory.class);
    Mustang created = factory.create(Color.GREEN);
    assertNotSame(providedMustang, created);
    assertEquals(Color.BLUE, providedMustang.color);
    assertEquals(Color.GREEN, created.color);
  }

  public void testExplicitForwardingAssistedBindingFailsWithInterface() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          bind(Volkswagen.class).to(Golf.class);
          install(new FactoryModuleBuilder()
            .implement(Car.class, Volkswagen.class)
            .build(ColoredCarFactory.class));
        }
      });
      fail();
    } catch (CreationException ce) {
      assertContains(
          ce.getMessage(), "1) " + Volkswagen.class.getName() + " is an interface, not a concrete class.",
          "Unable to create AssistedInject factory.",
          "while locating " + Volkswagen.class.getName(),
          "while locating " + Car.class.getName(),
          "at " + ColoredCarFactory.class.getName() + ".create(");
      assertEquals(1, ce.getErrorMessages().size());
    }
  }

  public void testExplicitForwardingAssistedBindingFailsWithAbstractClass() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          bind(AbstractCar.class).to(ArtCar.class);
          install(new FactoryModuleBuilder()
            .implement(Car.class, AbstractCar.class)
            .build(ColoredCarFactory.class));
        }
      });
      fail();
    } catch (CreationException ce) {
      assertContains(
          ce.getMessage(), "1) " + AbstractCar.class.getName() + " is abstract, not a concrete class.",
          "Unable to create AssistedInject factory.",
          "while locating " + AbstractCar.class.getName(),
          "while locating " + Car.class.getName(),
          "at " + ColoredCarFactory.class.getName() + ".create(");
      assertEquals(1, ce.getErrorMessages().size());
    }
  }
  
  public void testExplicitForwardingAssistedBindingCreatesNewObjects() {
    final Mustang providedMustang = new Mustang(Color.BLUE);
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        install(new FactoryModuleBuilder().implement(Car.class, Mustang.class).build(
            ColoredCarFactory.class));
      }
      @Provides Mustang provide() { return providedMustang; }
    });
    assertSame(providedMustang, injector.getInstance(Mustang.class));
    ColoredCarFactory factory = injector.getInstance(ColoredCarFactory.class);
    Mustang created = (Mustang)factory.create(Color.GREEN);
    assertNotSame(providedMustang, created);
    assertEquals(Color.BLUE, providedMustang.color);
    assertEquals(Color.GREEN, created.color);
  }

  public void testAnnotatedAndParentBoundReturnValue() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        bind(Car.class).to(Golf.class);

        bind(Integer.class).toInstance(911);
        bind(Double.class).toInstance(5.0d);
        install(new FactoryModuleBuilder()
            .implement(Car.class, Names.named("german"), Beetle.class)
            .implement(Car.class, Names.named("american"), Mustang.class)
            .build(AnnotatedVersatileCarFactory.class));
      }
    });

    AnnotatedVersatileCarFactory factory = injector.getInstance(AnnotatedVersatileCarFactory.class);
    assertTrue(factory.getGermanCar(Color.BLACK) instanceof Beetle);
    assertTrue(injector.getInstance(Car.class) instanceof Golf);
  }

  public void testParentBoundReturnValue() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        bind(Car.class).to(Golf.class);
        bind(Double.class).toInstance(5.0d);
        install(new FactoryModuleBuilder()
            .implement(Car.class, Mustang.class)
            .build(ColoredCarFactory.class));
      }
    });

    ColoredCarFactory factory = injector.getInstance(ColoredCarFactory.class);
    assertTrue(factory.create(Color.RED) instanceof Mustang);
    assertTrue(injector.getInstance(Car.class) instanceof Golf);
  }

  public void testConfigureAnnotatedReturnValue() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        install(new FactoryModuleBuilder()
            .implement(Car.class, Names.named("german"), Beetle.class)
            .implement(Car.class, Names.named("american"), Mustang.class)
            .build(AnnotatedVersatileCarFactory.class));
      }
    });

    AnnotatedVersatileCarFactory factory = injector.getInstance(AnnotatedVersatileCarFactory.class);
    assertTrue(factory.getGermanCar(Color.GRAY) instanceof Beetle);
    assertTrue(factory.getAmericanCar(Color.BLACK) instanceof Mustang);
  }

  public void testNoBindingAssistedInject() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        install(new FactoryModuleBuilder().build(MustangFactory.class));
      }
    });

    MustangFactory factory = injector.getInstance(MustangFactory.class);

    Mustang mustang = factory.create(Color.BLUE);
    assertEquals(Color.BLUE, mustang.color);
  }

  public void testBindingAssistedInject() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        install(new FactoryModuleBuilder()
            .implement(Car.class, Mustang.class)
            .build(ColoredCarFactory.class));
      }
    });

    ColoredCarFactory factory = injector.getInstance(ColoredCarFactory.class);

    Mustang mustang = (Mustang) factory.create(Color.BLUE);
    assertEquals(Color.BLUE, mustang.color);
  }

  public void testDuplicateBindings() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        install(new FactoryModuleBuilder()
            .implement(Car.class, Mustang.class)
            .build(ColoredCarFactory.class));
        install(new FactoryModuleBuilder()
            .implement(Car.class, Mustang.class)
            .build(ColoredCarFactory.class));
      }
    });

    ColoredCarFactory factory = injector.getInstance(ColoredCarFactory.class);

    Mustang mustang = (Mustang) factory.create(Color.BLUE);
    assertEquals(Color.BLUE, mustang.color);
  }

  public void testSimilarBindingsWithConflictingImplementations() {
    try {
      Injector injector = Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          install(new FactoryModuleBuilder()
              .implement(Car.class, Mustang.class)
              .build(ColoredCarFactory.class));
          install(new FactoryModuleBuilder()
              .implement(Car.class, Golf.class)
              .build(ColoredCarFactory.class));
        }
      });
      injector.getInstance(ColoredCarFactory.class);
      fail();
    } catch (CreationException ce) {
      assertContains(ce.getMessage(),
          "A binding to " + ColoredCarFactory.class.getName() + " was already configured");
      assertEquals(1, ce.getErrorMessages().size());
    }
  }

  public void testMultipleReturnTypes() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        bind(Double.class).toInstance(5.0d);
        install(new FactoryModuleBuilder().build(VersatileCarFactory.class));
      }
    });

    VersatileCarFactory factory = injector.getInstance(VersatileCarFactory.class);

    Mustang mustang = factory.getMustang(Color.RED);
    assertEquals(Color.RED, mustang.color);

    Beetle beetle = factory.getBeetle(Color.GREEN);
    assertEquals(Color.GREEN, beetle.color);
  }
  
  public void testParameterizedClassesWithNoImplements() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
        install(new FactoryModuleBuilder().build(new TypeLiteral<Foo.Factory() {}));
      }
    });
    
    Foo.Factory<String> factory = injector.getInstance(Key.get(new TypeLiteral>() {}));
    @SuppressWarnings("unused")
    Foo<String> foo = factory.create(new Bar());
  }
  
  public void testGenericErrorMessageMakesSense() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
         install(new FactoryModuleBuilder().build(Key.get(Foo.Factory.class))); 
        }
      });
      fail();
    } catch(CreationException ce ) {
      // Assert not only that it's the correct message, but also that it's the *only* message.
      Collection<Message> messages = ce.getErrorMessages();
      assertEquals(
          Foo.Factory.class.getName() + " cannot be used as a key; It is not fully specified.", 
          Iterables.getOnlyElement(messages).getMessage());
    }
  }

  interface Car {}

  interface Volkswagen extends Car {}

  interface ColoredCarFactory {
    Car create(Color color);
  }

  interface MustangFactory {
    Mustang create(Color color);
  }

  interface VersatileCarFactory {
    Mustang getMustang(Color color);
    Beetle getBeetle(Color color);
  }

  interface AnnotatedVersatileCarFactory {
    @Named("german") Car getGermanCar(Color color);
    @Named("american") Car getAmericanCar(Color color);
  }

  public static class Golf implements Volkswagen {}

  public static class Mustang implements Car {
    private final Color color;
    @Inject
    public Mustang(@Assisted Color color) {
      this.color = color;
    }
  }

  public static class Beetle implements Car {
    private final Color color;
    @Inject
    public Beetle(@Assisted Color color) {
      this.color = color;
    }
  }
  
  public static class Foo<E> {
    static interface Factory<E> {
      Foo<E> create(Bar bar);
    }
    @SuppressWarnings("unused")
    @Inject Foo(@Assisted Bar bar, Baz<E> baz) {}
  }
  
  public static class Bar {}
  @SuppressWarnings("unused")
  public static class Baz<E> {}
  
  abstract static class AbstractCar implements Car {}  
  interface ColoredAbstractCarFactory {
    AbstractCar create(Color color);
  }  
  public static class ArtCar extends AbstractCar {}
    
  public void testFactoryBindingDependencies() {
    // validate dependencies work in all stages & as a raw element,
    // and that dependencies work for methods, fields, constructors,
    // and for @AssistedInject constructors too.
    Module module = new AbstractModule() {
      @Override
      protected void configure() {
        bind(Integer.class).toInstance(42);
        bind(Double.class).toInstance(4.2d);
        bind(Float.class).toInstance(4.2f);
        bind(String.class).annotatedWith(named("dog")).toInstance("dog");
        bind(String.class).annotatedWith(named("cat1")).toInstance("cat1");
        bind(String.class).annotatedWith(named("cat2")).toInstance("cat2");
        bind(String.class).annotatedWith(named("cat3")).toInstance("cat3");
        bind(String.class).annotatedWith(named("arbitrary")).toInstance("fail!");
        install(new FactoryModuleBuilder()
                .implement(Animal.class, Dog.class)
                .build(AnimalHouse.class));
      }
    };

    Set<Key expectedKeys = ImmutableSet.>of(
        Key.get(Integer.class),
        Key.get(Double.class),
        Key.get(Float.class),
        Key.get(String.class, named("dog")),
        Key.get(String.class, named("cat1")),
        Key.get(String.class, named("cat2")),
        Key.get(String.class, named("cat3"))
    );
    
    Injector injector = Guice.createInjector(module);
    validateDependencies(expectedKeys, injector.getBinding(AnimalHouse.class));
    
    injector = Guice.createInjector(Stage.TOOL, module);
    validateDependencies(expectedKeys, injector.getBinding(AnimalHouse.class));
    
    List<Element> elements = Elements.getElements(module);
    boolean found = false;
    for(Element element : elements) {
      if(element instanceof Binding) {
        Binding<?> binding = (Binding) element;
        if(binding.getKey().equals(Key.get(AnimalHouse.class))) {
          found = true;
          validateDependencies(expectedKeys, binding);
          break;
        }
      }
    }
    assertTrue(found);
  }
  
  private void validateDependencies(Set<Key expectedKeys, Binding binding) {
    Set<Dependency dependencies = ((HasDependencies)binding).getDependencies();
    Set<Key actualKeys = new HashSet>();
    for (Dependency<?> dependency : dependencies) {
      actualKeys.add(dependency.getKey());
    }
    assertEquals(expectedKeys, actualKeys);
  }
  
  interface AnimalHouse {
    Animal createAnimal(String name);
    Cat createCat(String name);
    Cat createCat(int age);
  }
  
  interface Animal {}
  @SuppressWarnings("unused")
  private static class Dog implements Animal {
    @Inject int a;
    @Inject Dog(@Assisted String a, double b) {}
    @Inject void register(@Named("dog") String a) {}
  }
  @SuppressWarnings("unused")
  private static class Cat implements Animal {
    @Inject float a;
    @AssistedInject Cat(@Assisted String a, @Named("cat1") String b) {}
    @AssistedInject Cat(@Assisted int a, @Named("cat2") String b) {}
    @AssistedInject Cat(@Assisted byte a, @Named("catfail") String b) {} // not a dependency!
    @Inject void register(@Named("cat3") String a) {}
  }
  
  public void testFactoryPublicAndReturnTypeNotPublic() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          install(new FactoryModuleBuilder()
              .implement(Hidden.class, HiddenImpl.class)
              .build(NotHidden.class));
        }
      });
    } catch(CreationException ce) {
      assertEquals(NotHidden.class.getName() + " is public, but has a method that returns a non-public type: "
          + Hidden.class.getName() + ". Due to limitations with java.lang.reflect.Proxy, this is not allowed. "
          + "Please either make the factory non-public or the return type public.",           
          Iterables.getOnlyElement(ce.getErrorMessages()).getMessage());
    }
  }
  
  interface Hidden {}
  public static class HiddenImpl implements Hidden {}
  public interface NotHidden {
    Hidden create();
  }
  
  public void testSingletonScopeOnAssistedClassIsIgnored() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override
        protected void configure() {
          install(new FactoryModuleBuilder().build(SingletonFactory.class));
        }
      });
      fail();
    } catch (CreationException ce) {
      assertEquals(1, ce.getErrorMessages().size());
      assertEquals("Found scope annotation [" + Singleton.class.getName() + "]"
          + " on implementation class [" + AssistedSingleton.class.getName() + "]"
          + " of AssistedInject factory [" + SingletonFactory.class.getName() + "]."
          + "\nThis is not allowed, please remove the scope annotation.",
          Iterables.getOnlyElement(ce.getErrorMessages()).getMessage());
    }
  }
  
  interface SingletonFactory {
    AssistedSingleton create(String string);
  }

  @SuppressWarnings("GuiceAssistedInjectScoping")
  @Singleton
  static class AssistedSingleton {
    @Inject
    public AssistedSingleton(@SuppressWarnings("unused") @Assisted String string) {
    }
  }
  
}