1. 导入的retrofit2包的版本必须要一致，否则就会报错
    compile 'io.reactivex:rxjava:1.1.0'//Rx的包
    compile 'io.reactivex:rxandroid:1.1.0'//Rx的包
    compile 'com.squareup.retrofit2:retrofit:2.0.0-beta4'//Retrofit2所需要的包
    compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta4'//ConverterFactory的Gson依赖包
    compile 'com.squareup.retrofit2:adapter-rxjava:2.0.0-beta4'//CallAdapterFactory的Rx依赖包
    compile 'com.squareup.retrofit2:converter-scalars:2.0.0-beta4'//ConverterFactory的String依赖包
    compile 'com.google.code.gson:gson:2.6.2'//Gosn解析包
2. Retrofit提供的请求方式注解有@GET和@POST，参数注解有@PATH和@Field等，我们只介绍常用的;前两个顾名思义就是定义你的请求方式Get or Post
    @PATH  指的是通过参数填充完整的路径
        @GET("{name}")
           Call<User> getUser(@Path("name") String name);
        这里的参数username会被填充至{name}中，形成完整的Url请求地址，{name}相当于一个占位符；
    @Query  就是我们的请求的键值对的设置，我们构建Call对象的时候会传入此参数，
    @FormUrlEncoded  在post中使用
        @POST("mobileLogin/submit.html")
            @FormUrlEncoded
            Call<String> getString(@Field("loginname") String loginname,
                                  @Field("nloginpwd") String nloginpwd);
    @Field("loginname")就是键，后面的loginname就是具体的值了
    @POST 使用post方式,指明url
    @GET 使用get方式

compile 'com.squareup.retrofit:retrofit:2.0.0-beta2'
compile 'com.squareup.retrofit:converter-gson:2.0.0-beta2'

编写API服务代码
public interface NewsService {
    @GET("lore/list?")
    Call<NewsEntity> getNewsContent(@Query("page") int page, @Query("rows") int rows);
}

     newsService = RetrofitFactory.getNewsService();
     Call<NewsEntity> call = newsService.getNewsContent(page, rows);
     call.enqueue(new Callback<NewsEntity>() {
         @Override
         public void onResponse(Call<NewsEntity> call, Response<NewsEntity> response) {
         //  请求数据成功
             Toast.makeText(MainActivity.this, "success", Toast.LENGTH_SHORT).show();
             st.setText(response.code()+" "+response.message()+" "+response.body().getTotal()+"  "+response.body().getTngou().get(0).getDescription());
         }

         @Override
         public void onFailure(Call<NewsEntity> call, Throwable t) {
             // 请求数据失败
             Toast.makeText(MainActivity.this, "failure", Toast.LENGTH_SHORT).show();
         }
     });

通过@POST指明url，添加@FormUrlEncoded，然后通过@Field添加参数即可
public interface NewsService {
    @POST("login/app/user")
     @FormUrlEncoded
    Call<NewsEntity> getUser(@FieldMap Map<String, String> hashMap );
}

@Multipart
@POST("addPaster.html")
Call<String> updateImage(@Part MultipartBody.Part  file);

//多张图片上传
 @Multipart
 @POST("addPaster.html")
 Call<String> updateImage(@Part MultipartBody.Part[]  file);

//图文上传
 @Multipart
 @POST("android/paster/addPaster.html")
 Call<DefaultResult> updateImage(@Part MultipartBody.Part[] parts,@QueryMap Map<String, String> maps);

将证书拷贝到raw目录下
都知道Retrofit的网络请求是使用okhttp，所以我们只需要给
OkHttpClient.Builder().sslSocketFactory(sslSocketFactory)，那么SSLSocketFactory怎么得到呢，哈哈，不要急，方法已经写好：
public class SslContextFactory {
private static final String CLIENT_TRUST_PASSWORD = "changeit";//信任证书密码，该证书默认密码是changeit
private static final String CLIENT_AGREEMENT = "TLS";//使用协议
private static final String CLIENT_TRUST_MANAGER = "X509";
private static final String CLIENT_TRUST_KEYSTORE = "BKS";
SSLContext sslContext = null;
public SSLContext getSslSocket() {
try {
//取得SSL的SSLContext实例
sslContext = SSLContext.getInstance(CLIENT_AGREEMENT);
//取得TrustManagerFactory的X509密钥管理器实例
TrustManagerFactory trustManager = TrustManagerFactory.getInstance(CLIENT_TRUST_MANAGER);
//取得BKS密库实例
KeyStore tks = KeyStore.getInstance(CLIENT_TRUST_KEYSTORE);
InputStream is = MyApplication.getInstance().getResources().openRawResource(R.raw.suplcerts);
try {
tks.load(is, CLIENT_TRUST_PASSWORD.toCharArray());
} finally {
is.close();
}
//初始化密钥管理器
trustManager.init(tks);
//初始化SSLContext
sslContext.init(null, trustManager.getTrustManagers(), null);
} catch (Exception e) {
Log.e("SslContextFactory", e.getMessage());
}
return sslContext;    }}

给OkHttpClient.Builder().sslSocketFactory(sslSocketFactory)
SSLSocketFactory sslSocketFactory = new SslContextFactory().getSslSocket().getSocketFactory();
OkHttpClient.Builder okHttpClient = new OkHttpClient.Builder().sslSocketFactory(sslSocketFactory);

创建Retrofit对象
Retrofit retrofit = new Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())//增加返回值为Gson的支持(以实体类返回)
.baseUrl("https://skyish-test.yunext.com")//主机地址
.client(okHttpClient.build())       /注意这里要给retrofit 设置okhttpclient
.build();

http://www.cnblogs.com/angeldevil/p/3757335.html

http://square.github.io/retrofit/

http://www.jianshu.com/p/eb5d03085926

https://daidingkang.cc/2016/06/17/Retrofit2-network-framework-parsing/

http://www.2cto.com/kf/201605/510999.html

http://www.jianshu.com/p/29c2a9ac5abf

http://www.cnblogs.com/ut2016-progam/p/5687798.html

https://github.com/ervinsae/EZCode/commit/83281cfa79982ed40f1ca31fa1f4dafb4d7a49cb

http://www.jianshu.com/p/9a6c204616d2