3

网络请求–Retrofit2使用方法

 3 years ago
source link: http://www.androidchina.net/4302.html
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
neoserver,ios ssh client

Retrofit是Square开发的网络请求库, 简化了网络请求的使用, 这个库太知名了, 好处我就不多说了. 让我们看看如何使用吧?

注意: Retrofit2的beta3版本, 使用Okhttp3, Interceptor使用方式发生改变.

Retrofit

(1) Retrofit2(beta3)的请求方式.

(2) Okhttp3的Interceptor.

(3) Okhttp3的Deserializer.

(4) Retrofit2使用Gson转换器(Converter)和RxJava适配器(Adapter).

Github下载地址

1. 基本请求

使用接口, 区分Get和Post方法.

/**
* 网络请求
* <p>
* Created by wangchenlong on 16/1/21.
*/
public interface MarvelService {
String END_POINT = "http://gateway.marvel.com/";
String PARAM_API_KEY = "apikey";
String PARAM_HASH = "hash";
String PARAM_TIMESTAMP = "ts";
@GET("/v1/public/characters")
Observable<List<AvengersCharacter>> getCharacters(@Query("offset") int offset);
}

使用Retrofit类创建接口服务, 指定Gson为转换器, RxJava为适配器.

public class RestDataSource implements Repository {
private final MarvelService mMarvelService;
@Inject
public RestDataSource() {
// Log信息
HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BASIC);
// 公私密匙
MarvelSigningInterceptor signingInterceptor = new MarvelSigningInterceptor(
BuildConfig.MARVEL_PUBLIC_KEY, BuildConfig.MARVEL_PRIVATE_KEY);
// OkHttp3.0的使用方式
OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(signingInterceptor)
.addInterceptor(loggingInterceptor)
.build();
// 选择人物信息
Gson customGsonInstance = new GsonBuilder()
.registerTypeAdapter(new TypeToken<List<AvengersCharacter>>() {
}.getType(),
new MarvelResultsDeserializer<AvengersCharacter>())
.create();
// 适配器
Retrofit marvelApiAdapter = new Retrofit.Builder()
.baseUrl(MarvelService.END_POINT)
.addConverterFactory(GsonConverterFactory.create(customGsonInstance))
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.client(client)
.build();
// 服务
mMarvelService = marvelApiAdapter.create(MarvelService.class);
}
// 返回人物信息
@Override
public Observable<List<AvengersCharacter>> getCharacters(int currentOffset) {
return mMarvelService.getCharacters(currentOffset);
}
}

2. Interceptor

Interceptor是拦截器, 在发送之前, 添加一些参数, 或者获取一些信息.

如MarvelSigningInterceptor是添加参数, loggingInterceptor是打印参数.

/**
* 添加Key和密码
* <p>
* Created by wangchenlong on 16/1/21.
*/
public class MarvelSigningInterceptor implements Interceptor {
private final String mApiKey;
private final String mApiSecret;
public MarvelSigningInterceptor(String apiKey, String apiSecret) {
mApiKey = apiKey;
mApiSecret = apiSecret;
}
@Override public Response intercept(Interceptor.Chain chain) throws IOException {
String marvelHash = MarvelApiUtils.generateMarvelHash(mApiKey, mApiSecret);
Request oldRequest = chain.request();
// 添加新的参数
HttpUrl.Builder authorizedUrlBuilder = oldRequest.url()
.newBuilder()
.scheme(oldRequest.url().scheme())
.host(oldRequest.url().host())
.addQueryParameter(MarvelService.PARAM_API_KEY, mApiKey)
.addQueryParameter(MarvelService.PARAM_TIMESTAMP, MarvelApiUtils.getUnixTimeStamp())
.addQueryParameter(MarvelService.PARAM_HASH, marvelHash);
// 新的请求
Request newRequest = oldRequest.newBuilder()
.method(oldRequest.method(), oldRequest.body())
.url(authorizedUrlBuilder.build())
.build();
return chain.proceed(newRequest);
}
}

addQueryParameter添加网络参数.

Okhttp3使用了装饰者模式, 使用Builder添加Interceptor.

// OkHttp3.0的使用方式
OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(signingInterceptor)
.addInterceptor(loggingInterceptor)
.build();

3. Deserializer

Deserializer是反序列化, Gson使用, 去除不使用的参数.

public class MarvelResultsDeserializer<T> implements JsonDeserializer<List<T>> {
@Override
public List<T> deserialize(JsonElement je, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
// 转换Json的数据, 获取内部有用的信息
JsonElement results = je.getAsJsonObject().get("data")
.getAsJsonObject().get("results");
return new Gson().fromJson(results, typeOfT);
}
}

Gson使用Deserializer, 过滤不用的参数.

// 选择人物信息
Gson customGsonInstance = new GsonBuilder()
.registerTypeAdapter(new TypeToken<List<AvengersCharacter>>() {
}.getType(),
new MarvelResultsDeserializer<AvengersCharacter>())
.create();

4. 获取数据

Rx选择执行线程和返回线程.

private void loadData() {
mCharactersSubscription = mRepository.getCharacters(0)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(avengersCharacters -> {
mMainView.setListData(avengersCharacters);
});
}

Rxjava+Dagger+Retrofit, 三个编程库, 都已经写完了, 基本都是在一起使用. 文章里面都含有独立Demo, 大家可以配合使用, 感谢Square给我们带来, 的优雅代码.

OK, that’s all! Enjoy it.

转载请注明：Android开发中文站 » 网络请求–Retrofit2使用方法


report

Recommend

About Joyk


Aggregate valuable and interesting links.
Joyk means Joy of geeK