# CORS (オリジン間リソース共有)

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORSまたは「オリジン間リソース共有」</a> は、ブラウザで実行されているフロントエンドにバックエンドと通信するJavaScriptコードがあり、そのバックエンドがフロントエンドとは異なる「オリジン」にある状況を指します。

## オリジン

オリジンはプロトコル (`http`、`https`) とドメイン (`myapp.com`、`localhost`、`localhost.tiangolo.com`) とポート (`80`、`443`、`8080`) の組み合わせです。

したがって、以下はすべて異なるオリジンです:

* `http://localhost`
* `https://localhost`

import java.util.Iterator;
import java.util.Map.Entry;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code remove} operations on a map. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author George van den Driessche
 * @author Chris Povirk
 */
@GwtCompatible

import static org.mockito.Mockito.when;

import com.google.common.testing.NullPointerTester;
import java.io.ByteArrayInputStream;
import java.util.Arrays;
import junit.framework.TestCase;

/**
 * Tests for {@link HashingInputStream}.
 *
 * @author Qian Huang
 */
public class HashingInputStreamTest extends TestCase {
  private Hasher hasher;
  private HashFunction hashFunction;

import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import java.util.Arrays;
import java.util.List;
import junit.framework.TestCase;

/**
 * Unit tests for {@link AbstractPackageSanityTests}.
 *
 * @author Ben Yu
 */
public class AbstractPackageSanityTestsTest extends TestCase {
  /*
   * This is a public type so that the Android test runner can create an instance directly as it

import java.util.NavigableSet;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingSortedMultiset}.
 *
 * @author Louis Wasserman
 */
public class ForwardingSortedMultisetTest extends TestCase {
  static class StandardImplForwardingSortedMultiset<E> extends ForwardingSortedMultiset<E> {

 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
 *       to "undo" {@link ElementTypesAreNonnullByDefault}. It is the best we can do for Kotlin
 *       under our current constraints.
 *   <li>NullAway, which will <a

import java.util.concurrent.ConcurrentMap;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code replace(K, V, V)} operations on a concurrent map. Can't
 * be invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.FakeTicker;
import junit.framework.TestCase;

/**
 * Unit test for {@link Stopwatch}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
public class StopwatchTest extends TestCase {

  private final FakeTicker ticker = new FakeTicker();

import static org.mockito.Mockito.when;

import com.google.common.testing.NullPointerTester;
import java.io.ByteArrayInputStream;
import java.util.Arrays;
import junit.framework.TestCase;

/**
 * Tests for {@link HashingInputStream}.
 *
 * @author Qian Huang
 */
public class HashingInputStreamTest extends TestCase {
  private Hasher hasher;
  private HashFunction hashFunction;

import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterators;
import java.util.Iterator;
import junit.framework.TestCase;

/**
 * Tests for {@link SubscriberRegistry}.
 *
 * @author Colin Decker
 */
public class SubscriberRegistryTest extends TestCase {

  private final SubscriberRegistry registry = new SubscriberRegistry(new EventBus());