Es gibt viele Situationen, in denen Sie einem Client, der Ihre API benutzt, einen Fehler zurückgeben müssen.

Dieser Client könnte ein Browser mit einem Frontend, Code von jemand anderem, ein <abbr title="Internet of Things – Internet der Dinge: Geräte, die über das Internet Informationen austauschen">IoT</abbr>-Gerät, usw., sein.

Sie müssten beispielsweise einem Client sagen:

* Dass er nicht die notwendigen Berechtigungen hat, eine Aktion auszuführen.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools" package="okhttp.android.testapp">

  <uses-permission android:name="android.permission.INTERNET" />

  <application
    android:allowBackup="true"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:name=".TestApplication"
  >
    <activity
      android:name=".MainActivity"

  @SuppressWarnings("FutureReturnValueIgnored")
  @Footprint(exclude = {Runnable.class, Executor.class, Thread.class, Exception.class})
  public Object measureSize() {
    for (Thread thread : blockedThreads) {
      thread.interrupt();
    }
    blockedThreads.clear();
    final Facade<Object> f = impl.newFacade();
    for (int i = 0; i < numThreads; i++) {
      Thread thread =
          new Thread() {
            @Override

    )
  }

  if (androidBuild) {
    sourceSets["androidTest"].java.srcDirs(
      "../okhttp-brotli/src/test/java",
      "../okhttp-dnsoverhttps/src/test/java",
      "../okhttp-logging-interceptor/src/test/java",
      "../okhttp-sse/src/test/java"
    )
  }

  compileOptions {
    targetCompatibility(JavaVersion.VERSION_11)
    sourceCompatibility(JavaVersion.VERSION_11)
  }

  testOptions {

      super(
          new Runnable() {
            @Override
            public void run() {
              while (!shutdown.get()) {
                interruptee.interrupt();
                Thread.yield();
              }
            }
          });
      this.shutdown = shutdown;
      start();
    }

 *  Fix: Don't log gzipped data in the logging interceptor.
 *  Fix: Don't resolve DNS addresses when connecting through a SOCKS proxy.
 *  Fix: Drop the synthetic `OkHttp-Selected-Protocol` response header.
 *  Fix: Support 204 and 205 'No Content' replies in the logging interceptor.
 *  New: Add `Call.isExecuted()`.


## Version 2.6.0

_2015-11-22_

 *  **New Logging Interceptor.** The `logging-interceptor` subproject offers

        logger.finer(
            Platform.format(
                "%s: skipping because these features are absent: %s", method, missingFeatures));
      }
      return false;
    }
    if (intersect(features, requirements.getAbsentFeatures())) {
      if (logger.isLoggable(FINER)) {
        Set<Feature<?>> unwantedFeatures = copyToSet(requirements.getAbsentFeatures());
        unwantedFeatures.retainAll(features);

   * Device Control 1. Characters for the control of ancillary devices associated with data
   * processing or telecommunication systems, more especially switching devices "on" or "off." (If a
   * single "stop" control is required to interrupt or turn off ancillary devices, DC4 is the
   * preferred assignment.)
   *
   * @since 8.0
   */
  public static final byte DC1 = 17; // aka XON

  /**

 * ordinary tests.
 *
 * <p>Failure of the expected event to occur within an implementation-defined "reasonable" time
 * period or an interrupt while waiting for the expected event will result in a {@link
 * RuntimeException}.
 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * <pre>{@code
 * final CountDownLatch latch = new CountDownLatch(1);

    validator.validateClass(exceptionClass);
    try {
      return future.get();
    } catch (InterruptedException e) {
      currentThread().interrupt();
      throw newWithCause(exceptionClass, e);
    } catch (ExecutionException e) {
      wrapAndThrowExceptionOrError(e.getCause(), exceptionClass);
      throw new AssertionError();
    }
  }