You can check a web server's configuration using [Qualys SSL Labs][qualys]. OkHttp's TLS
configuration history is [tracked here](../security/tls_configuration_history.md).

Applications expected to be installed on older Android devices should consider adopting the
[Google Play Services’ ProviderInstaller][provider_installer]. This will increase security for users
and increase connectivity with web servers.

 *
 *  * DER: Distinguished Encoding Rules. This further constrains ASN.1 for deterministic encoding.
 *  * BER: Basic Encoding Rules.
 *
 * This class was implemented according to the [X.690 spec][[x690]], and under the advice of
 * [Lets Encrypt's ASN.1 and DER][asn1_and_der] guide.
 *
 * [x690]: https://www.itu.int/rec/T-REC-X.690
 * [asn1_and_der]: https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/
 */

    assertThat(get(url).body.string()).isEqualTo("a")

    // The URL will remain available if hasNext() returned true...
    val i = cache.urls()
    assertThat(i.hasNext()).isTrue()

    // ...so even when we evict the element, we still get something back.
    cache.evictAll()
    assertThat(i.next()).isEqualTo(url.toString())

    // Remove does nothing. But most importantly, it doesn't throw!
    i.remove()
  }

watson.jp
weblike.jp
whitesnow.jp
zombie.jp
heteml.net

// GOV.UK Platform as a Service : https://www.cloud.service.gov.uk/
// Submitted by Tom Whitwell <******@****.***>
cloudapps.digital
london.cloudapps.digital

// GOV.UK Pay : https://www.payments.service.gov.uk/
// Submitted by Richard Baker <******@****.***>
pymnt.uk

        }

        // if the new or replacement header is too big, drop all entries.
        if (delta > maxDynamicTableByteCount) {
          clearDynamicTable()
          return
        }

        // Evict headers to the required length.
        val bytesToRecover = dynamicTableByteCount + delta - maxDynamicTableByteCount
        val entriesEvicted = evictToRecoverBytes(bytesToRecover)

      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

serveftp.com serveftp.net serveftp.org servegame.com servegame.org servehalflife.com servehttp.com servehumour.com serveirc.com serveminecraft.net servemp3.com servep2p.com servepics.com servequake.com servers.run servesarcasm.com service.gov.scot service.gov.uk service.one services services.aero setagaya.tokyo.jp seto.aichi.jp setouchi.okayama.jp settlement.museum settlers.museum settsu.osaka.jp sevastopol.ua seven sew sex sex.hu sex.pl sexy sf.no sfr sg sg-1.paas.massivegrid.net sh sh.cn shacknet.nu...

        .build()
    val request = Request(server.url("/"))
    val response1 = client.newCall(request).execute()
    assertThat(response1.body.string()).isEqualTo("a")

    // Give the thread pool a chance to evict.
    Thread.sleep(500)
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("b")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

        }
      }
    ```

### Posting a String ([.kt][PostStringKotlin], [.java][PostStringJava])

Use an HTTP POST to send a request body to a service. This example posts a markdown document to a web service that renders markdown as HTML. Because the entire request body is in memory simultaneously, avoid posting large (greater than 1 MiB) documents using this API.

=== ":material-language-kotlin: Kotlin"

        .socketPolicy(DisconnectDuringRequestBody)
        .build(),
    )
    // Limit the size of the request body that the server holds in memory to an arbitrary
    // 3.5 MBytes so this test can pass on devices with little memory.
    server.bodyLimit = 7 * 512 * 1024
    val connection = server.url("/").toUrl().openConnection() as HttpURLConnection
    connection.requestMethod = "POST"
    connection.doOutput = true