对于Retrofit:2.0.0-beta4，代码如下:

OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(logging)
    .connectTimeout(30, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .writeTimeout(30, TimeUnit.SECONDS)
    .build();

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://api.yourapp.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .client(client)
    .build();

现在已经变了。用.newBuilder()替换.Builder()

从okhttp:3.9.0开始，代码如下:

OkHttpClient okHttpClient = new OkHttpClient()
    .newBuilder()
    .connectTimeout(10,TimeUnit.SECONDS)
    .writeTimeout(10,TimeUnit.SECONDS)
    .readTimeout(30,TimeUnit.SECONDS)
    .build();

像这样:

//New Request
HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BASIC);
final OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(logging)
    .connectTimeout(30, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .writeTimeout(30, TimeUnit.SECONDS)
    .build();

对于Retrofit:2.0.0-beta4，代码如下:

OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(logging)
    .connectTimeout(30, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .writeTimeout(30, TimeUnit.SECONDS)
    .build();

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://api.yourapp.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .client(client)
    .build();

OkHttp版本:3.11.0或更高

从okhttp源代码:

/**
 * Sets the default connect timeout for new connections. A value of 0 means no timeout,
 * otherwise values must be between 1 and {@link Integer#MAX_VALUE} when converted to
 * milliseconds.
 *
 * <p>The connectTimeout is applied when connecting a TCP socket to the target host.
 * The default value is 10 seconds.
 */
public Builder connectTimeout(long timeout, TimeUnit unit) {
    connectTimeout = checkDuration("timeout", timeout, unit);
    return this;
}

单位可以是以下的任何值

TimeUnit.NANOSECONDS
TimeUnit.MICROSECONDS
TimeUnit.MILLISECONDS
TimeUnit.SECONDS
TimeUnit.MINUTES
TimeUnit.HOURS
TimeUnit.DAYS

示例代码

OkHttpClient client = new OkHttpClient.Builder()
    .connectTimeout(5000, TimeUnit.MILLISECONDS)/*timeout: 5 seconds*/
    .build();

String url = "https://www.google.com";
Request request = new Request.Builder()
    .url(url)
    .build();

try {
    Response response = client.newCall(request).execute();
} catch (IOException e) {
    e.printStackTrace();
}

更新

我已经从3.12.0版本添加了新的API到OkHttp，你可以这样设置超时:

OkHttpClient client = new OkHttpClient.Builder()
    .connectTimeout(Duration.ofSeconds(5)) // timeout: 5 seconds
    .build();

注意:这需要API 26+，所以如果你支持旧版本的Android，继续使用(5,TimeUnit.SECONDS)。

对于okhttp3，这有一点变化。

现在你使用构建器而不是setter来设置时间，就像这样:

OkHttpClient client = new OkHttpClient.Builder()
        .connectTimeout(10, TimeUnit.SECONDS)
        .writeTimeout(10, TimeUnit.SECONDS)
        .readTimeout(30, TimeUnit.SECONDS)
        .build();

更多信息可以在他们的维基上找到: https://github.com/square/okhttp/blob/b3dcb9b1871325248fba917458658628c44ce8a3/docs/recipes.md#timeouts-kt-java