Applications that want to use the global SSL context with OkHttp should configure their
OkHttpClient instances with the following:

```java
okHttpClient.setSslSocketFactory(HttpsURLConnection.getDefaultSSLSocketFactory());
```

A simpler solution is to avoid the shared default SSL socket factory. Instead, if you
need to customize SSL, do so for your specific OkHttpClient instance only.

##### Synthetic headers have changed

![Events Diagram](../assets/images/******@****.***)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java
class PrintingEventListener extends EventListener {

import javax.net.ssl.SSLSocket
import okhttp3.Protocol
import okhttp3.internal.platform.BouncyCastlePlatform
import okhttp3.internal.platform.Platform
import org.bouncycastle.jsse.BCSSLSocket

/**
 * Simple non-reflection SocketAdapter for BouncyCastle.
 */
class BouncyCastleSocketAdapter : SocketAdapter {
  override fun matchesSocket(sslSocket: SSLSocket): Boolean = sslSocket is BCSSLSocket

/**
 * Simplified from
 * https://hc.apache.org/httpcomponents-client-5.0.x/httpclient5/examples/AsyncClientTlsAlpn.java
 *
 * Mainly intended to verify behaviour of popular clients across Android versions, similar
 * to observing Firefox or Chrome browser behaviour.
 */
class ApacheHttpClientHttp2Test {
  @Test
  fun testHttp2() {
    val client = HttpAsyncClients.createHttp2Default()

    client.use { client ->

 [CVE-2021-0341]: https://nvd.nist.gov/vuln/detail/CVE-2021-0341
 [CVE-2022-24329]: https://nvd.nist.gov/vuln/detail/CVE-2022-24329
 [dev_server]: https://github.com/square/okhttp/blob/482f88300f78c3419b04379fc26c3683c10d6a9d/samples/guide/src/main/java/okhttp3/recipes/kt/DevServer.kt
 [fun_interface]: https://kotlinlang.org/docs/reference/fun-interfaces.html
 [iana_websocket]: https://www.iana.org/assignments/websocket/websocket.txt

    address[b++] = (value.ushr(8) and 0xff).toByte()
    address[b++] = (value and 0xff).toByte()
  }

  // All done. If compression happened, we need to move bytes to the right place in the
  // address. Here's a sample:
  //
  //      input: "1111:2222:3333::7777:8888"
  //     before: { 11, 11, 22, 22, 33, 33, 00, 00, 77, 77, 88, 88, 00, 00, 00, 00  }
  //   compress: 6
  //          b: 10

    val multipart =
      """
      |--simple boundary
      |
      |abcd
      |--simple boundary--
      """.trimMargin()
        .replace(Regex("(?m)simple boundary$"), "simple boundary \t \t")
        .replace("\n", "\r\n")

    val parts =
      MultipartReader(
        boundary = "simple boundary",
        source = Buffer().writeUtf8(multipart),
      )

# Calls

The HTTP client’s job is to accept your request and produce its response. This is simple in theory but it gets tricky in practice.

## [Requests](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-request/)

Each HTTP request contains a URL, a method (like `GET` or `POST`), and a list of headers. Requests may also contain a body: a data stream of a specific content type.

## [Responses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-response/)

 [conscrypt_dependency]: https://github.com/google/conscrypt/#download
 [grpc_http2]: https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
 [https_server_sample]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/HttpsServer.java
 [jetty_8_252]: https://webtide.com/jetty-alpn-java-8u252/

   */
  @Test
  fun literalHeaderFieldWithoutIndexingIndexedName() {
    val headerBlock = headerEntries(":path", "/sample/path")
    bytesIn.writeByte(0x04) // == Literal not indexed ==
    // Indexed name (idx = 4) -> :path
    bytesIn.writeByte(0x0c) // Literal value (len = 12)
    bytesIn.writeUtf8("/sample/path")
    hpackWriter!!.writeHeaders(headerBlock)
    assertThat(bytesOut).isEqualTo(bytesIn)