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Java example source code file (OptionalBinderTest.java)

This example Java source code file (OptionalBinderTest.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, annotation, exception, has_java_optional, hasdependencies, injector, key, module, optional, optionalbinder, override, reflection, set, string, stringgrabber, typeliteral, util

The OptionalBinderTest.java Java example source code

/**
 * Copyright (C) 2014 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.multibindings;

import static com.google.inject.Asserts.assertContains;
import static com.google.inject.multibindings.SpiUtils.assertOptionalVisitor;
import static com.google.inject.multibindings.SpiUtils.instance;
import static com.google.inject.multibindings.SpiUtils.linked;
import static com.google.inject.multibindings.SpiUtils.providerInstance;
import static com.google.inject.multibindings.SpiUtils.providerKey;
import static com.google.inject.name.Names.named;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.inject.AbstractModule;
import com.google.inject.Asserts;
import com.google.inject.Binding;
import com.google.inject.BindingAnnotation;
import com.google.inject.CreationException;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.Module;
import com.google.inject.Provider;
import com.google.inject.Provides;
import com.google.inject.Scopes;
import com.google.inject.TypeLiteral;
import com.google.inject.internal.WeakKeySetUtils;
import com.google.inject.multibindings.OptionalBinder.Actual;
import com.google.inject.multibindings.OptionalBinder.Default;
import com.google.inject.multibindings.SpiUtils.VisitType;
import com.google.inject.name.Named;
import com.google.inject.name.Names;
import com.google.inject.spi.Dependency;
import com.google.inject.spi.Elements;
import com.google.inject.spi.HasDependencies;
import com.google.inject.spi.InstanceBinding;
import com.google.inject.util.Modules;
import com.google.inject.util.Providers;

import junit.framework.TestCase;

import java.lang.annotation.Annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.ref.WeakReference;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;

/**
 * @author sameb@google.com (Sam Berlin)
 */
public class OptionalBinderTest extends TestCase {

  private static final boolean HAS_JAVA_OPTIONAL;
  private static final Class<?> JAVA_OPTIONAL_CLASS;
  private static final Method JAVA_OPTIONAL_OR_ELSE;
  static {
    Class<?> optional = null;
    Method orElse = null;
    try {
      optional = Class.forName("java.util.Optional");
      orElse = optional.getDeclaredMethod("orElse", Object.class);
    } catch (ClassNotFoundException ignored) {
    } catch (NoSuchMethodException ignored) {
    } catch (SecurityException ignored) {
    }
    HAS_JAVA_OPTIONAL = optional != null;
    JAVA_OPTIONAL_CLASS = optional;
    JAVA_OPTIONAL_OR_ELSE = orElse;
  }

  final Key<String> stringKey = Key.get(String.class);
  final TypeLiteral<Optional optionalOfString = new TypeLiteral>() {};
  final TypeLiteral<?> javaOptionalOfString =  HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOf(stringKey.getTypeLiteral()) : null;
  final TypeLiteral<Optional> optionalOfProviderString =
      new TypeLiteral<Optional>() {};
  final TypeLiteral<?> javaOptionalOfProviderString = HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOfProvider(stringKey.getTypeLiteral()) : null;
  final TypeLiteral<Optional> optionalOfJavaxProviderString =
      new TypeLiteral<Optional>() {};
  final TypeLiteral<?> javaOptionalOfJavaxProviderString = HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOfJavaxProvider(stringKey.getTypeLiteral()) : null;

  final Key<Integer> intKey = Key.get(Integer.class);
  final TypeLiteral<Optional optionalOfInteger = new TypeLiteral>() {};
  final TypeLiteral<?> javaOptionalOfInteger =  HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOf(intKey.getTypeLiteral()) : null;
  final TypeLiteral<Optional> optionalOfProviderInteger =
      new TypeLiteral<Optional>() {};
  final TypeLiteral<?> javaOptionalOfProviderInteger = HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOfProvider(intKey.getTypeLiteral()) : null;
  final TypeLiteral<Optional> optionalOfJavaxProviderInteger =
      new TypeLiteral<Optional>() {};
  final TypeLiteral<?> javaOptionalOfJavaxProviderInteger = HAS_JAVA_OPTIONAL ?
      OptionalBinder.javaOptionalOfJavaxProvider(intKey.getTypeLiteral()) : null;

  final TypeLiteral<List listOfStrings = new TypeLiteral>() {};

  public void testTypeNotBoundByDefault() {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class);
        requireBinding(new Key<Optional() {}); // the above specifies this.
        requireBinding(String.class); // but it doesn't specify this.
        binder().requireExplicitBindings(); // need to do this, otherwise String will JIT

        if (HAS_JAVA_OPTIONAL) {
          requireBinding(Key.get(javaOptionalOfString));
        }
      }
    };

    try {
      Guice.createInjector(module);
      fail();
    } catch (CreationException ce) {
      assertContains(ce.getMessage(),
          "1) Explicit bindings are required and java.lang.String is not explicitly bound.");
      assertEquals(1, ce.getErrorMessages().size());
    }
  } 
  
  public void testOptionalIsAbsentByDefault() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class);
      }
    };

    Injector injector = Guice.createInjector(module);
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertFalse(optional.isPresent());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertFalse(optionalP.isPresent());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertFalse(optionalJxP.isPresent());
    
    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 0, null, null, null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertFalse(optional.isPresent());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertFalse(optionalP.isPresent());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertFalse(optionalJxP.isPresent());
    }
  }
  
  public void testUsesUserBoundValue() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class);
      }
      @Provides String provideString() { return "foo"; }
    };

    Injector injector = Guice.createInjector(module);
    assertEquals("foo", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertEquals("foo", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertEquals("foo", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertEquals("foo", optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module),
        VisitType.BOTH,
        0,
        null,
        null,
        providerInstance("foo"));

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertEquals("foo", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertEquals("foo", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertEquals("foo", optionalJxP.get().get());
    }
  }
  
  public void testSetDefault() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("a", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("a", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("a", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("a", optionalJxP.get().get());

    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 0, instance("a"), null, null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("a", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("a", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("a", optionalJxP.get().get());
    }
  }
  
  public void testSetBinding() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("a");
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("a", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("a", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("a", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("a", optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 0, null, instance("a"), null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("a", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("a", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("a", optionalJxP.get().get());
    }
  }
  
  public void testSetBindingOverridesDefault() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> optionalBinder =
            OptionalBinder.newOptionalBinder(binder(), String.class);
        optionalBinder.setDefault().toInstance("a");
        optionalBinder.setBinding().toInstance("b");
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("b", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("b", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("b", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("b", optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module),
        VisitType.BOTH,
        0,
        instance("a"),
        instance("b"),
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("b", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("b", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("b", optionalJxP.get().get());
    }
  }
  
  public void testSpreadAcrossModules() throws Exception {
    Module module1 = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class);
      }
    };
    Module module2 = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
      }
    };
    Module module3 = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("b");
      }
    };

    Injector injector = Guice.createInjector(module1, module2, module3);
    assertEquals("b", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("b", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("b", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("b", optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module1, module2, module3),
        VisitType.BOTH,
        0,
        instance("a"),
        instance("b"),
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("b", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("b", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("b", optionalJxP.get().get());
    }
  }
  
  public void testExactSameBindingCollapses_defaults() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault()
            .toInstance(new String("a")); // using new String to ensure .equals is checked.
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault()
            .toInstance(new String("a"));
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("a", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("a", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("a", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("a", optionalJxP.get().get());

    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 0, instance("a"), null, null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("a", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("a", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("a", optionalJxP.get().get());
    }
  }
  
  public void testExactSameBindingCollapses_actual() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding()
            .toInstance(new String("a")); // using new String to ensure .equals is checked.
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding()
            .toInstance(new String("a"));
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("a", injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertTrue(optional.isPresent());
    assertEquals("a", optional.get());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertEquals("a", optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertEquals("a", optionalJxP.get().get());

    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 0, null, instance("a"), null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertTrue(optional.isPresent());
      assertEquals("a", optional.get());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertEquals("a", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertEquals("a", optionalJxP.get().get());
    }
  }
  
  public void testDifferentBindingsFail_defaults() {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("b");
      }
    };
    try {
      Guice.createInjector(module);
      fail();
    } catch (CreationException ce) {
      assertEquals(ce.getMessage(), 1, ce.getErrorMessages().size());
      assertContains(ce.getMessage(),
          "1) A binding to java.lang.String annotated with @" 
              + Default.class.getName() + " was already configured at "
              + module.getClass().getName() + ".configure(",
          "at " + module.getClass().getName() + ".configure(");
    }
  }  
  
  public void testDifferentBindingsFail_actual() {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("a");
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("b");
      }
    };
    try {
      Guice.createInjector(module);
      fail();
    } catch (CreationException ce) {
      assertEquals(ce.getMessage(), 1, ce.getErrorMessages().size());
      assertContains(ce.getMessage(),
          "1) A binding to java.lang.String annotated with @" 
              + Actual.class.getName() + " was already configured at "
              + module.getClass().getName() + ".configure(",
          "at " + module.getClass().getName() + ".configure(");
    }
  }  
  
  public void testDifferentBindingsFail_both() {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("b");
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("b");
        OptionalBinder.newOptionalBinder(binder(), String.class).setBinding().toInstance("c");
      }
    };
    try {
      Guice.createInjector(module);
      fail();
    } catch (CreationException ce) {
      assertEquals(ce.getMessage(), 2, ce.getErrorMessages().size());      
      assertContains(ce.getMessage(),
          "1) A binding to java.lang.String annotated with @"
              + Default.class.getName() + " was already configured at "
              + module.getClass().getName() + ".configure(",
          "at " + module.getClass().getName() + ".configure(",
          "2) A binding to java.lang.String annotated with @"
              + Actual.class.getName() + " was already configured at "
              + module.getClass().getName() + ".configure(",
          "at " + module.getClass().getName() + ".configure(");
    }
  }
  
  public void testQualifiedAggregatesTogether() throws Exception {
    Module module1 = new AbstractModule() {
      @Override
      protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), Key.get(String.class, Names.named("foo")));
      }
    };
    Module module2 = new AbstractModule() {
      @Override
      protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), Key.get(String.class, Names.named("foo")))
            .setDefault().toInstance("a");
      }
    };
    Module module3 = new AbstractModule() {
      @Override
      protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), Key.get(String.class, Names.named("foo")))
            .setBinding().toInstance("b");
      }
    };

    Injector injector = Guice.createInjector(module1, module2, module3);
    assertEquals("b", injector.getInstance(Key.get(String.class, Names.named("foo"))));

    Optional<String> optional = injector.getInstance(Key.get(optionalOfString, Names.named("foo")));
    assertTrue(optional.isPresent());
    assertEquals("b", optional.get());

    Optional<Provider optionalP =
        injector.getInstance(Key.get(optionalOfProviderString, Names.named("foo")));
    assertTrue(optionalP.isPresent());
    assertEquals("b", optionalP.get().get());

    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString, Names.named("foo")));
    assertTrue(optionalJxP.isPresent());
    assertEquals("b", optionalJxP.get().get());
    
    assertOptionalVisitor(Key.get(String.class, Names.named("foo")),
        setOf(module1, module2, module3),
        VisitType.BOTH,
        0,
        instance("a"),
        instance("b"),
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString, Names.named("foo"))));
      assertTrue(optional.isPresent());
      assertEquals("b", optional.get());

      optionalP = toOptional(injector.getInstance
          (Key.get(javaOptionalOfProviderString, Names.named("foo"))));
      assertTrue(optionalP.isPresent());
      assertEquals("b", optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(
          Key.get(javaOptionalOfJavaxProviderString, Names.named("foo"))));
      assertTrue(optionalJxP.isPresent());
      assertEquals("b", optionalJxP.get().get());
    }
  }
  
  public void testMultipleDifferentOptionals() {
    final Key<String> bKey = Key.get(String.class, named("b"));
    final Key<String> cKey = Key.get(String.class, named("c"));
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
        OptionalBinder.newOptionalBinder(binder(), Integer.class).setDefault().toInstance(1);
        
        OptionalBinder.newOptionalBinder(binder(), bKey).setDefault().toInstance("b");
        OptionalBinder.newOptionalBinder(binder(), cKey).setDefault().toInstance("c");
      }
    };
    Injector injector = Guice.createInjector(module);
    assertEquals("a", injector.getInstance(String.class));
    assertEquals(1, injector.getInstance(Integer.class).intValue());
    assertEquals("b", injector.getInstance(bKey));
    assertEquals("c", injector.getInstance(cKey));
    
    assertOptionalVisitor(stringKey, setOf(module), VisitType.BOTH, 3, instance("a"), null, null);
    assertOptionalVisitor(intKey, setOf(module), VisitType.BOTH, 3, instance(1), null, null);
    assertOptionalVisitor(bKey, setOf(module), VisitType.BOTH, 3, instance("b"), null, null);
    assertOptionalVisitor(cKey, setOf(module), VisitType.BOTH, 3, instance("c"), null, null);
  }
  
  public void testOptionalIsAppropriatelyLazy() throws Exception {
    Module module = new AbstractModule() {
      int nextValue = 1;
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), Integer.class)
            .setDefault().to(Key.get(Integer.class, Names.named("foo")));
      }
      @Provides @Named("foo") int provideInt() {
        return nextValue++;
      }
    };
    Injector injector = Guice.createInjector(module);

    Optional<Provider optionalP =
        injector.getInstance(Key.get(optionalOfProviderInteger));
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderInteger));
    
    assertEquals(1, injector.getInstance(Integer.class).intValue());
    assertEquals(2, injector.getInstance(Integer.class).intValue());
    
    // Calling .get() on an Optional<Integer> multiple times will keep giving the same thing
    Optional<Integer> optional = injector.getInstance(Key.get(optionalOfInteger));
    assertEquals(3, optional.get().intValue());
    assertEquals(3, optional.get().intValue());
    // But getting another Optional<Integer> will give a new one.
    assertEquals(4, injector.getInstance(Key.get(optionalOfInteger)).get().intValue());
    
    // And the Optional<Provider> will return a provider that gives a new value each time.
    assertEquals(5, optionalP.get().get().intValue());
    assertEquals(6, optionalP.get().get().intValue());
    
    assertEquals(7, optionalJxP.get().get().intValue());
    assertEquals(8, optionalJxP.get().get().intValue());

    // and same rules with java.util.Optional
    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfInteger)));
      assertEquals(9, optional.get().intValue());
      assertEquals(9, optional.get().intValue());
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfInteger)));
      assertEquals(10, optional.get().intValue());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderInteger)));
      assertEquals(11, optionalP.get().get().intValue());
      assertEquals(12, optionalP.get().get().intValue());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderInteger)));
      assertEquals(13, optionalJxP.get().get().intValue());
      assertEquals(14, optionalJxP.get().get().intValue());
    }
  }
  
  public void testLinkedToNullProvidersMakeAbsentValuesAndPresentProviders_default()
      throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class)
            .setDefault().toProvider(Providers.<String>of(null));
      }
    };
    Injector injector = Guice.createInjector(module);
    assertNull(injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertFalse(optional.isPresent());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertNull(optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertNull(optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module),
        VisitType.BOTH,
        0,
        SpiUtils.<String>providerInstance(null),
        null,
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertFalse(optional.isPresent());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertNull(optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertNull(optionalJxP.get().get());
    }
  }
  
  public void testLinkedToNullProvidersMakeAbsentValuesAndPresentProviders_actual()
      throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class)
            .setBinding().toProvider(Providers.<String>of(null));
      }
    };
    Injector injector = Guice.createInjector(module);
    assertNull(injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertFalse(optional.isPresent());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertNull(optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertNull(optionalJxP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module),
        VisitType.BOTH,
        0,
        null,
        SpiUtils.<String>providerInstance(null),
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertFalse(optional.isPresent());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertNull(optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertNull(optionalJxP.get().get());
    }
  }
  
  // TODO(sameb): Maybe change this?
  public void testLinkedToNullActualDoesntFallbackToDefault() throws Exception {
    Module module = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder.newOptionalBinder(binder(), String.class).setDefault().toInstance("a");
        OptionalBinder.newOptionalBinder(binder(), String.class)
            .setBinding().toProvider(Providers.<String>of(null));
      }
    };
    Injector injector = Guice.createInjector(module);
    assertNull(injector.getInstance(String.class));
    
    Optional<String> optional = injector.getInstance(Key.get(optionalOfString));
    assertFalse(optional.isPresent());
    
    Optional<Provider optionalP = injector.getInstance(Key.get(optionalOfProviderString));
    assertTrue(optionalP.isPresent());
    assertNull(optionalP.get().get());
    
    Optional<javax.inject.Provider optionalJxP =
        injector.getInstance(Key.get(optionalOfJavaxProviderString));
    assertTrue(optionalJxP.isPresent());
    assertNull(optionalP.get().get());
    
    assertOptionalVisitor(stringKey,
        setOf(module),
        VisitType.BOTH,
        0,
        instance("a"),
        SpiUtils.<String>providerInstance(null),
        null);

    if (HAS_JAVA_OPTIONAL) {
      optional = toOptional(injector.getInstance(Key.get(javaOptionalOfString)));
      assertFalse(optional.isPresent());

      optionalP = toOptional(injector.getInstance(Key.get(javaOptionalOfProviderString)));
      assertTrue(optionalP.isPresent());
      assertNull(optionalP.get().get());

      optionalJxP = toOptional(injector.getInstance(Key.get(javaOptionalOfJavaxProviderString)));
      assertTrue(optionalJxP.isPresent());
      assertNull(optionalJxP.get().get());
    }
  }

  public void testSourceLinesInException() {
    try {
      Guice.createInjector(new AbstractModule() {
        @Override protected void configure() {
          OptionalBinder.newOptionalBinder(binder(),  Integer.class).setDefault();
        }
      });
      fail();
    } catch (CreationException expected) {
      assertContains(expected.getMessage(), "No implementation for java.lang.Integer",
          "at " + getClass().getName());
    }
  }

  public void testDependencies_both() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> optionalbinder =
            OptionalBinder.newOptionalBinder(binder(), String.class);
        optionalbinder.setDefault().toInstance("A");
        optionalbinder.setBinding().to(Key.get(String.class, Names.named("b")));
        bindConstant().annotatedWith(Names.named("b")).to("B");
      }
    });

    Binding<String> binding = injector.getBinding(Key.get(String.class));
    HasDependencies withDependencies = (HasDependencies) binding;
    Set<String> elements = Sets.newHashSet();
    elements.addAll(recurseForDependencies(injector, withDependencies));
    assertEquals(ImmutableSet.of("B"), elements);
  }

  public void testDependencies_actual() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> optionalbinder =
            OptionalBinder.newOptionalBinder(binder(), String.class);
        optionalbinder.setBinding().to(Key.get(String.class, Names.named("b")));
        bindConstant().annotatedWith(Names.named("b")).to("B");
      }
    });

    Binding<String> binding = injector.getBinding(Key.get(String.class));
    HasDependencies withDependencies = (HasDependencies) binding;
    Set<String> elements = Sets.newHashSet();
    elements.addAll(recurseForDependencies(injector, withDependencies));
    assertEquals(ImmutableSet.of("B"), elements);
  }

  public void testDependencies_default() {
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> optionalbinder =
            OptionalBinder.newOptionalBinder(binder(), String.class);
        optionalbinder.setDefault().toInstance("A");
      }
    });

    Binding<String> binding = injector.getBinding(Key.get(String.class));
    HasDependencies withDependencies = (HasDependencies) binding;
    Set<String> elements = Sets.newHashSet();
    elements.addAll(recurseForDependencies(injector, withDependencies));
    assertEquals(ImmutableSet.of("A"), elements);
  }
  
  @SuppressWarnings("rawtypes")
  private Set<String> recurseForDependencies(Injector injector, HasDependencies hasDependencies) {
    Set<String> elements = Sets.newHashSet();
    for (Dependency<?> dependency : hasDependencies.getDependencies()) {
      Binding<?> binding = injector.getBinding(dependency.getKey());
      HasDependencies deps = (HasDependencies) binding;
      if (binding instanceof InstanceBinding) {
        elements.add((String) ((InstanceBinding) binding).getInstance());
      } else {
        elements.addAll(recurseForDependencies(injector, deps));
      }
    }    
    return elements;
  }

  /**
   * Doubly-installed modules should not conflict, even when one is overridden.
   */
  public void testModuleOverrideRepeatedInstalls_toInstance() {
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> b = OptionalBinder.newOptionalBinder(binder(), String.class);
        b.setDefault().toInstance("A");
        b.setBinding().toInstance("B");
      }
    };

    assertEquals("B", Guice.createInjector(m, m).getInstance(Key.get(String.class)));

    Injector injector = Guice.createInjector(m, Modules.override(m).with(m));
    assertEquals("B", injector.getInstance(Key.get(String.class)));

    assertOptionalVisitor(stringKey,
        setOf(m, Modules.override(m).with(m)),
        VisitType.BOTH,
        0,
        instance("A"),
        instance("B"),
        null);
  }

  public void testModuleOverrideRepeatedInstalls_toKey() {
    final Key<String> aKey = Key.get(String.class, Names.named("A_string"));
    final Key<String> bKey = Key.get(String.class, Names.named("B_string"));
    Module m = new AbstractModule() {
      @Override protected void configure() {
        bind(aKey).toInstance("A");
        bind(bKey).toInstance("B");

        OptionalBinder<String> b = OptionalBinder.newOptionalBinder(binder(), String.class);
        b.setDefault().to(aKey);
        b.setBinding().to(bKey);
      }
    };

    assertEquals("B", Guice.createInjector(m, m).getInstance(Key.get(String.class)));

    Injector injector = Guice.createInjector(m, Modules.override(m).with(m));
    assertEquals("B", injector.getInstance(Key.get(String.class)));

    assertOptionalVisitor(stringKey,
        setOf(m, Modules.override(m).with(m)),
        VisitType.BOTH,
        0,
        linked(aKey),
        linked(bKey),
        null);
  }

  public void testModuleOverrideRepeatedInstalls_toProviderInstance() {
    // Providers#of() does not redefine equals/hashCode, so use the same one both times.
    final Provider<String> aProvider = Providers.of("A");
    final Provider<String> bProvider = Providers.of("B");
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> b = OptionalBinder.newOptionalBinder(binder(), String.class);
        b.setDefault().toProvider(aProvider);
        b.setBinding().toProvider(bProvider);
      }
    };

    assertEquals("B", Guice.createInjector(m, m).getInstance(Key.get(String.class)));

    Injector injector = Guice.createInjector(m, Modules.override(m).with(m));
    assertEquals("B", injector.getInstance(Key.get(String.class)));

    assertOptionalVisitor(stringKey,
        setOf(m, Modules.override(m).with(m)),
        VisitType.BOTH,
        0,
        providerInstance("A"),
        providerInstance("B"),
        null);
  }

  private static class AStringProvider implements Provider<String> {
    public String get() {
      return "A";
    }
  }

  private static class BStringProvider implements Provider<String> {
    public String get() {
      return "B";
    }
  }

  public void testModuleOverrideRepeatedInstalls_toProviderKey() {
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<String> b = OptionalBinder.newOptionalBinder(binder(), String.class);
        b.setDefault().toProvider(Key.get(AStringProvider.class));
        b.setBinding().toProvider(Key.get(BStringProvider.class));
      }
    };

    assertEquals("B", Guice.createInjector(m, m).getInstance(Key.get(String.class)));

    Injector injector = Guice.createInjector(m, Modules.override(m).with(m));
    assertEquals("B", injector.getInstance(Key.get(String.class)));

    assertOptionalVisitor(stringKey,
        setOf(m, Modules.override(m).with(m)),
        VisitType.BOTH,
        0,
        providerKey(Key.get(AStringProvider.class)),
        providerKey(Key.get(BStringProvider.class)),
        null);
  }

  private static class StringGrabber {
    private final String string;

    @SuppressWarnings("unused")  // Found by reflection
    public StringGrabber(@Named("A_string") String string) {
      this.string = string;
    }

    @SuppressWarnings("unused")  // Found by reflection
    public StringGrabber(@Named("B_string") String string, int unused) {
      this.string = string;
    }

    @Override
    public int hashCode() {
      return string.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
      return (obj instanceof StringGrabber) && ((StringGrabber) obj).string.equals(string);
    }

    @Override
    public String toString() {
      return "StringGrabber(" + string + ")";
    }
  }

  public void testModuleOverrideRepeatedInstalls_toConstructor() {
    Module m = new AbstractModule() {
      @Override protected void configure() {
        Key<String> aKey = Key.get(String.class, Names.named("A_string"));
        Key<String> bKey = Key.get(String.class, Names.named("B_string"));
        bind(aKey).toInstance("A");
        bind(bKey).toInstance("B");
        bind(Integer.class).toInstance(0);  // used to disambiguate constructors


        OptionalBinder<StringGrabber> b =
            OptionalBinder.newOptionalBinder(binder(), StringGrabber.class);
        try {
          b.setDefault().toConstructor(
              StringGrabber.class.getConstructor(String.class));
          b.setBinding().toConstructor(
              StringGrabber.class.getConstructor(String.class, int.class));
        } catch (NoSuchMethodException e) {
          fail("No such method: " + e.getMessage());
        }
      }
    };

    assertEquals("B", Guice.createInjector(m, m).getInstance(Key.get(StringGrabber.class)).string);

    Injector injector = Guice.createInjector(m, Modules.override(m).with(m));
    assertEquals("B", injector.getInstance(Key.get(StringGrabber.class)).string);
  }

  /**
   * Unscoped bindings should not conflict, whether they were bound with no explicit scope, or
   * explicitly bound in {@link Scopes#NO_SCOPE}.
   */
  public void testDuplicateUnscopedBindings() {
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<Integer> b = OptionalBinder.newOptionalBinder(binder(), Integer.class);
        b.setDefault().to(Key.get(Integer.class, named("foo")));
        b.setDefault().to(Key.get(Integer.class, named("foo"))).in(Scopes.NO_SCOPE);
        b.setBinding().to(Key.get(Integer.class, named("foo")));
        b.setBinding().to(Key.get(Integer.class, named("foo"))).in(Scopes.NO_SCOPE);
      }
      @Provides @Named("foo") int provideInt() { return 5; }
    };
    assertEquals(5, Guice.createInjector(m).getInstance(Integer.class).intValue());
  }

  /**
   * Ensure key hash codes are fixed at injection time, not binding time.
   */
  public void testKeyHashCodesFixedAtInjectionTime() {
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<List b = OptionalBinder.newOptionalBinder(binder(), listOfStrings);
        List<String> list = Lists.newArrayList();
        b.setDefault().toInstance(list);
        b.setBinding().toInstance(list);
        list.add("A");
        list.add("B");
      }
    };

    Injector injector = Guice.createInjector(m);
    for (Entry<Key> entry : injector.getAllBindings().entrySet()) {
      Key<?> bindingKey = entry.getKey();
      Key<?> clonedKey;
      if (bindingKey.getAnnotation() != null) {
        clonedKey = Key.get(bindingKey.getTypeLiteral(), bindingKey.getAnnotation());
      } else if (bindingKey.getAnnotationType() != null) {
        clonedKey = Key.get(bindingKey.getTypeLiteral(), bindingKey.getAnnotationType());
      } else {
        clonedKey = Key.get(bindingKey.getTypeLiteral());
      }
      assertEquals(bindingKey, clonedKey);
      assertEquals("Incorrect hashcode for " + bindingKey + " -> " + entry.getValue(),
          bindingKey.hashCode(), clonedKey.hashCode());
    }
  }

  /**
   * Ensure bindings do not rehash their keys once returned from {@link Elements#getElements}.
   */
  public void testBindingKeysFixedOnReturnFromGetElements() {
    final List<String> list = Lists.newArrayList();
    Module m = new AbstractModule() {
      @Override protected void configure() {
        OptionalBinder<List b = OptionalBinder.newOptionalBinder(binder(), listOfStrings);
        b.setDefault().toInstance(list);
        list.add("A");
        list.add("B");
      }
    };

    InstanceBinding<?> binding = Iterables.getOnlyElement(
        Iterables.filter(Elements.getElements(m), InstanceBinding.class));
    Key<?> keyBefore = binding.getKey();
    assertEquals(listOfStrings, keyBefore.getTypeLiteral());

    list.add("C");
    Key<?> keyAfter = binding.getKey();
    assertSame(keyBefore, keyAfter);
  }

  @BindingAnnotation
  @Retention(RetentionPolicy.RUNTIME)
  @Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
  private static @interface Marker {}

  @Marker
  public void testMatchingMarkerAnnotations() throws Exception {
    Method m = OptionalBinderTest.class.getDeclaredMethod("testMatchingMarkerAnnotations");
    assertNotNull(m);
    final Annotation marker = m.getAnnotation(Marker.class);
    Injector injector = Guice.createInjector(new AbstractModule() {
      @Override public void configure() {
        OptionalBinder<Integer> mb1 =
            OptionalBinder.newOptionalBinder(binder(), Key.get(Integer.class, Marker.class));
        OptionalBinder<Integer> mb2 =
            OptionalBinder.newOptionalBinder(binder(), Key.get(Integer.class, marker));
        mb1.setDefault().toInstance(1);
        mb2.setBinding().toInstance(2);

        // This assures us that the two binders are equivalent, so we expect the instance added to
        // each to have been added to one set.
        assertEquals(mb1, mb2);
      }
    });
    Integer i1 = injector.getInstance(Key.get(Integer.class, Marker.class));
    Integer i2 = injector.getInstance(Key.get(Integer.class, marker));

    // These must be identical, because the marker annotations collapsed to the same thing.
    assertSame(i1, i2);
    assertEquals(2, i2.intValue());
  }
  
 // Tests for com.google.inject.internal.WeakKeySet not leaking memory.
 public void testWeakKeySet_integration() {   
   Injector parentInjector = Guice.createInjector(new AbstractModule() {
         @Override protected void configure() {
           bind(String.class).toInstance("hi");
         }
       });
   WeakKeySetUtils.assertNotBlacklisted(parentInjector, Key.get(Integer.class));

   Injector childInjector = parentInjector.createChildInjector(new AbstractModule() {
     @Override protected void configure() {
       OptionalBinder.newOptionalBinder(binder(), Integer.class).setDefault().toInstance(4);
     }
   });
   WeakReference<Injector> weakRef = new WeakReference(childInjector);
   WeakKeySetUtils.assertBlacklisted(parentInjector, Key.get(Integer.class));
   
   // Clear the ref, GC, and ensure that we are no longer blacklisting.
   childInjector = null;
   
   Asserts.awaitClear(weakRef);
   WeakKeySetUtils.assertNotBlacklisted(parentInjector, Key.get(Integer.class));
 }

 public void testCompareEqualsAgainstOtherAnnotation() {
   OptionalBinder.Actual impl1 = new OptionalBinder.ActualImpl("foo");
   OptionalBinder.Actual other1 = Dummy.class.getAnnotation(OptionalBinder.Actual.class);
   assertEquals(impl1, other1);

   OptionalBinder.Default impl2 = new OptionalBinder.DefaultImpl("foo");
   OptionalBinder.Default other2 = Dummy.class.getAnnotation(OptionalBinder.Default.class);
   assertEquals(impl2, other2);

   assertFalse(impl1.equals(impl2));
   assertFalse(impl1.equals(other2));
   assertFalse(impl2.equals(other1));
   assertFalse(other1.equals(other2));
 }

  @OptionalBinder.Actual("foo")
  @OptionalBinder.Default("foo")
  static class Dummy {}
  
  @SuppressWarnings("unchecked") 
  private <V> Set setOf(V... elements) {
    return ImmutableSet.copyOf(elements);
  }

  @SuppressWarnings("unchecked")
  private <T> Optional toOptional(Object object) throws Exception {
    assertTrue("not a java.util.Optional: " + object.getClass(),
        JAVA_OPTIONAL_CLASS.isInstance(object));
    return Optional.fromNullable((T) JAVA_OPTIONAL_OR_ELSE.invoke(object, (Void) null));
  }
}

Other Java examples (source code examples)

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