guice/core/test/com/google/inject/LoggerInjectionTest.java

package com.google.inject;

import static com.google.inject.Asserts.assertContains;

import com.google.inject.name.Names;
import java.util.logging.Logger;
import junit.framework.TestCase;

/**
 * Test built-in injection of loggers.
 *
 * @author jessewilson
 */
public class LoggerInjectionTest extends TestCase {

  @Inject Logger logger;

  public void testLoggerWithMember() {
    Injector injector = Guice.createInjector();
    injector.injectMembers(this);
    assertEquals("com.google.inject.LoggerInjectionTest", logger.getName());
  }

  public void testLoggerInConstructor() {
    Injector injector = Guice.createInjector();
    Foo foo = injector.getInstance(Foo.class);
    assertEquals("com.google.inject.LoggerInjectionTest$Foo", foo.logger.getName());
  }

  private static class Foo {
    Logger logger;

    @SuppressWarnings("unused")
    @Inject
    Foo(Logger logger) {
      this.logger = logger;
    }
  }

  public void testLoggerWithoutMember() {
    Injector injector = Guice.createInjector();
    assertNull(injector.getInstance(Logger.class).getName());
    assertNull(injector.getProvider(Logger.class).get().getName());
    assertNull(injector.getBinding(Logger.class).getProvider().get().getName());
    assertEquals("Provider<Logger>", injector.getProvider(Logger.class).toString());
  }

  public void testCanBindAnnotatedLogger() {
    Injector injector =
        Guice.createInjector(
            new AbstractModule() {
              @Override
              protected void configure() {
                bind(Logger.class)
                    .annotatedWith(Names.named("anonymous"))
                    .toInstance(Logger.getAnonymousLogger());
              }
            });

    assertNull(injector.getInstance(Key.get(Logger.class, Names.named("anonymous"))).getName());
  }

  public void testCannotBindLogger() {
    try {
      Guice.createInjector(
          new AbstractModule() {
            @Override
            protected void configure() {
              bind(Logger.class).toInstance(Logger.getAnonymousLogger());
            }
          });
      fail();
    } catch (CreationException expected) {
      assertContains(expected.getMessage(), "Logger was bound multiple times.");
    }
  }
}