![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 {
  private long callStartNanos;

    receiving stream to process it.

    This change may increase OkHttp's memory use for applications that make many concurrent HTTP
    calls and that can receive data faster than they can process it. Previously, OkHttp limited
    HTTP/2 to 16 MiB of unacknowledged data per connection. With this fix there is a limit of 16 MiB
    of unacknowledged data per stream and no per-connection limit.

    assertContent("mp3 data", response)
  }

  @Test
  fun ntripr1() {
    server.enqueue(
      MockResponse.Builder()
        .status("SOURCETABLE 200 OK")
        .addHeader("Server: NTRIP Caster 1.5.5/1.0")
        .addHeader("Date: 23/Jan/2004:08:54:59 UTC")
        .addHeader("Content-Type: text/plain")

 [conscrypt]: https://github.com/google/conscrypt/
 [get_example]: https://raw.github.com/square/okhttp/master/samples/guide/src/main/java/okhttp3/guide/GetExample.java
 [kotlin]: https://kotlinlang.org/
 [okhttp3_pro]: https://raw.githubusercontent.com/square/okhttp/master/okhttp/src/main/resources/META-INF/proguard/okhttp3.pro
 [okhttp_312x]: https://github.com/square/okhttp/tree/okhttp_3.12.x

    private val ONLY_HTTP1 = listOf(Protocol.HTTP_1_1)

    /**
     * The maximum number of bytes to enqueue. Rather than enqueueing beyond this limit we tear down
     * the web socket! It's possible that we're writing faster than the peer can read.
     */
    private const val MAX_QUEUE_SIZE = 16L * 1024 * 1024 // 16 MiB.

    /**
     * The maximum amount of time after the client calls [close] to wait for a graceful shutdown. If

    receiving stream to process it.

    This change may increase OkHttp's memory use for applications that make many concurrent HTTP
    calls and that can receive data faster than they can process it. Previously, OkHttp limited
    HTTP/2 to 16 MiB of unacknowledged data per connection. With this fix there is a limit of 16 MiB
    of unacknowledged data per stream and no per-connection limit.

 *  **Okio dependency added.** OkHttp now depends on
    [Okio](https://github.com/square/okio), an I/O library that makes it easier
    to access, store and process data. Using this library internally makes OkHttp
    faster while consuming less memory. You can write a `RequestBody` as an Okio
    `BufferedSink` and a `ResponseBody` as an Okio `BufferedSource`. Standard
    `InputStream` and `OutputStream` access is also available.

  value: String,
) = apply {
  headersCheckName(name)
  headersCheckValue(value, name)
  removeAll(name)
  commonAddLenient(name, value)
}

/** Equivalent to `build().get(name)`, but potentially faster. */
internal fun Headers.Builder.commonGet(name: String): String? {
  for (i in namesAndValues.size - 2 downTo 0 step 2) {
    if (name.equals(namesAndValues[i], ignoreCase = true)) {
      return namesAndValues[i + 1]

URLs that share the same address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections.

      }
    ```

 [CustomTrustJava]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/CustomTrust.java
 [CustomTrustKotlin]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/kt/CustomTrust.kt
 [CertificatePinningJava]: https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/CertificatePinning.java