okhttp 客户端超时和 apache 超时之间的区别

Question

In the past I used the http client of apache. I had settings for:

• Connection Request timeout
• Connect timeout
• Read/socket timeout
• ConnectionPool size

I am migrating to the OkHttp client and it has different timeouts:

• connect-timeout
• call-timeout
• read-timeout
• write-timeout
• max-idle-connections (connection pool setting)
• keep-alive-duration-minutes (connection pool setting)

How do they map to each other?

Regards,

Rick

Answer 1

Extracting from the excellent article written on Baeldung , here are a few details:

1. Connect Timeout:

   A connect timeout defines a time period in which our client should establish a connection with a target host. By default, for the OkHttpClient , this timeout is set to 10 seconds.

   However, we can easily change its value using the OkHttpClient.Builder#connectTimeout method. A value of zero means no timeout at all.

   Let's now see how to build and use an OkHttpClient with a custom connection timeout:

    @Test public void whenConnectTimeoutExceeded_thenSocketTimeoutException() { OkHttpClient client = new OkHttpClient.Builder().connectTimeout(10, TimeUnit.MILLISECONDS).build(); Request request = new Request.Builder().url("http://203.0.113.1") // non routable address.build(); Throwable thrown = catchThrowable(() -> client.newCall(request).execute()); assertThat(thrown).isInstanceOf(SocketTimeoutException.class); }

   The above example shows that the client throws a SocketTimeoutException when the connection attempt exceeds the configured timeout.

2. Call Timeout:

   A call timeout is a bit different than the connect, read and write timeouts we already discussed. It defines a time limit for a complete HTTP call . This includes resolving DNS, connecting, writing the request body, server processing, as well as reading the response body. Unlike other timeouts, it's default value is set to zero which implies no timeout . But of course, we can configure a custom value using OkHttpClient.Builder#callTimeout method.

   Let's see a practical usage example:

    @Test public void whenCallTimeoutExceeded_thenInterruptedIOException() { OkHttpClient client = new OkHttpClient.Builder().callTimeout(1, TimeUnit.SECONDS).build(); Request request = new Request.Builder().url("https://httpbin.org/delay/2").build(); Throwable thrown = catchThrowable(() -> client.newCall(request).execute()); assertThat(thrown).isInstanceOf(InterruptedIOException.class); }

3. Read Timeout:

   A read timeout is applied from the moment the connection between a client and a target host has been successfully established.

   It defines a maximum time of inactivity between two data packets when waiting for the server's response .

   The default timeout of 10 seconds can be changed using OkHttpClient.Builder#readTimeout . Analogously as for the connect timeout, a zero value indicates no timeout.

   Let's now see how to configure a custom read timeout in practice:

    @Test public void whenReadTimeoutExceeded_thenSocketTimeoutException() { OkHttpClient client = new OkHttpClient.Builder().readTimeout(10, TimeUnit.MILLISECONDS).build(); Request request = new Request.Builder().url("https://httpbin.org/delay/2") // 2-second response time.build(); Throwable thrown = catchThrowable(() -> client.newCall(request).execute()); assertThat(thrown).isInstanceOf(SocketTimeoutException.class); }

   As we can see, the server doesn't return the response within the defined timeout of 500 ms. As a result, the OkHttpClient throws a SocketTimeoutException .

4. Write Timeout:

   A write timeout defines a maximum time of inactivity between two data packets when sending the request to the server .

   Similarly, as for the connect and read timeouts, we can override the default value of 10 seconds using OkHttpClient.Builder#writeTimeout . As a convention, a zero value means no timeout at all.

   In the following example, we set a very short write timeout of 10 ms and post a 1 MB content to the server:

    @Test public void whenWriteTimeoutExceeded_thenSocketTimeoutException() { OkHttpClient client = new OkHttpClient.Builder().writeTimeout(10, TimeUnit.MILLISECONDS).build(); Request request = new Request.Builder().url("https://httpbin.org/delay/2").post(RequestBody.create(MediaType.parse("text/plain"), create1MBString())).build(); Throwable thrown = catchThrowable(() -> client.newCall(request).execute()); assertThat(thrown).isInstanceOf(SocketTimeoutException.class); }