[AccessHeadersJava]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/AccessHeaders.java
 [AccessHeadersKotlin]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/kt/AccessHeaders.kt
 [PostStringJava]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PostString.java

 * 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 okhttp3.recipes.kt

import java.io.File
import java.io.IOException
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.RequestBody

      .url(url)
      .post(body)
      .build();
  try (Response response = client.newCall(request).execute()) {
    return response.body().string();
  }
}
```

Further examples are on the [OkHttp Recipes page][recipes].


Requirements
------------

OkHttp works on Android 5.0+ (API level 21+) and Java 8+.

On Android, OkHttp uses [AndroidX Startup][androidx_startup]. If you disable the initializer in the manifest,

 * 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 okhttp3.recipes;

import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okio.Buffer;
import okio.BufferedSink;
import okio.ForwardingSink;

  static ParameterizedType newParameterizedType(Class<?> rawType, Type... arguments) {
    return new ParameterizedTypeImpl(
        ClassOwnership.JVM_BEHAVIOR.getOwnerType(rawType), rawType, arguments);
  }

  /** Decides what owner type to use for constructing {@link ParameterizedType} from a raw class. */
  private enum ClassOwnership {
    OWNED_BY_ENCLOSING_CLASS {
      @Override
      @Nullable Class<?> getOwnerType(Class<?> rawType) {

  static ParameterizedType newParameterizedType(Class<?> rawType, Type... arguments) {
    return new ParameterizedTypeImpl(
        ClassOwnership.JVM_BEHAVIOR.getOwnerType(rawType), rawType, arguments);
  }

  /** Decides what owner type to use for constructing {@link ParameterizedType} from a raw class. */
  private enum ClassOwnership {
    OWNED_BY_ENCLOSING_CLASS {
      @Override
      @Nullable Class<?> getOwnerType(Class<?> rawType) {

      this.actionWhenFirstParamIsNull = actionWhenFirstParamIsNull;
      this.actionWhenSecondParamIsNull = actionWhenSecondParamIsNull;
    }

    /** Method that decides how to react to parameters. */
    public void reactToNullParameters(@Nullable Object first, @Nullable Object second) {
      if (first == null) {
        actionWhenFirstParamIsNull.act();
      }