1、实例化OkHttpClient对象，OkHttpClient包含了以下属性，以及set()和get()方法。但并没有包含具体的执行方法，详情见源码。
//实例化OkHttpClent对象
private OkHttpClient client = new OkHttpClient();
private static SSLSocketFactory defaultSslSocketFactory;
private final RouteDatabase routeDatabase;
private Dispatcher dispatcher;
private Proxy proxy;
private List<Protocol> protocols;
private List<ConnectionSpec> connectionSpecs;
private final List<Interceptor> interceptors = new ArrayList<>();
private final List<Interceptor> networkInterceptors = new ArrayList<>();
private ProxySelector proxySelector;
private CookieHandler cookieHandler; /** Non-null if this client is caching; possibly by {@code cache}. */
private InternalCache internalCache;
private Cache cache; private SocketFactory socketFactory;
private SSLSocketFactory sslSocketFactory;
private HostnameVerifier hostnameVerifier;
private CertificatePinner certificatePinner;
private Authenticator authenticator;
private ConnectionPool connectionPool;
private Network network;
private boolean followSslRedirects = true;
private boolean followRedirects = true;
private boolean retryOnConnectionFailure = true;
private int connectTimeout = 10_000;
private int readTimeout = 10_000;
private int writeTimeout = 10_000;
2、实例化Request对象，大家可以参考Request源码。
(1)、大家可以先查考--java builder模式 http://www.cnblogs.com/moonz-wu/archive/2011/01/11/1932473.html
(2)、Request、Response即采用了Builder模式。
(3)、Request包含了HttpUrl、Method、Headers、RequestBody、Tag等参数。以及httpUrl()、method()、headers()、body()、tag()等方法(类似于get()方法)。
(4)、并没有包含有关网络操作和其他操作的方法。
3、实例化RequestBody方法，大家可以参考RequestBody源码。
(1)、第一可以通过RequestBody内部静态方法实现。
RequestBody body = RequestBody.create(final MediaType contentType, final ByteString content);
(2)、第二可以通过重写RequestBody的writeTo()和contentType()方法。
RequestBody body = new RequestBody() {
@Override
public void writeTo(BufferedSink arg0) throws IOException {
// TODO Auto-generated method stub
}
@Override
public MediaType contentType() {
// TODO Auto-generated method stub
return null;
}
};