003 okhttp超時與緩存

　　上文的介紹都沒添加，若是要添加，則按照下面的方式設置。

File sdcache = getExternalCacheDir();
int cacheSize = 10 * 1024 * 1024;
OkHttpClient.Builder builder = new OkHttpClient.Builder()
        .connectTimeout(15, TimeUnit.SECONDS)
        .writeTimeout(20, TimeUnit.SECONDS)
        .readTimeout(20, TimeUnit.SECONDS)
        .cache(new Cache(sdcache.getAbsoluteFile(), cacheSize));
OkHttpClient mOkHttpClient=builder.build();