CacheTest.java

import java.io.IOException;
import java.net.HttpURLConnection;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import java.util.concurrent.TimeUnit;
import okhttp3.Cache;
import okhttp3.HttpUrl;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.mockwebserver.MockResponse;
import okhttp3.mockwebserver.MockWebServer;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

import static org.junit.Assert.assertEquals;

public final class CacheTest {
  @Rule public MockWebServer server = new MockWebServer();
  @Rule public TemporaryFolder temp = new TemporaryFolder();

  @Test public void conditionalMissUpdatesCache2() throws Exception {
    Cache cache = new Cache(temp.getRoot(), Integer.MAX_VALUE);
    OkHttpClient client = new OkHttpClient.Builder()
        .cache(cache)
        .build();

    server.enqueue(new MockResponse()
        .addHeader("Last-Modified: " + formatDate(0, TimeUnit.SECONDS))
        .addHeader("Cache-Control: max-age=0")
        .setBody("A"));
    server.enqueue(new MockResponse()
        .addHeader("Cache-Control: max-age=30")
        .setBody("B"));

    // Cache miss seeds the cache.
    Response response1 = get(client, server.url("/a"));
    assertEquals("A", response1.body().string());
    assertEquals(null, response1.header("Allow"));

    // Cache miss updates the cache.
    Response response2 = get(client, server.url("/a"));
    assertEquals(HttpURLConnection.HTTP_OK, response2.code());
    assertEquals("B", response2.body().string());

    // Full cache hit returns data from the cache.
    Response response3 = get(client, server.url("/a"));
    assertEquals("B", response3.body().string());

    assertEquals(2, server.getRequestCount());
  }

  private Response get(OkHttpClient client, HttpUrl url) throws IOException {
    Request request = new Request.Builder()
        .url(url)
        .build();
    return client.newCall(request).execute();
  }

  private String formatDate(long delta, TimeUnit timeUnit) {
    return formatDate(new Date(System.currentTimeMillis() + timeUnit.toMillis(delta)));
  }

  private String formatDate(Date date) {
    DateFormat rfc1123 = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US);
    rfc1123.setTimeZone(TimeZone.getTimeZone("GMT"));
    return rfc1123.format(date);
  }
}