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Android使用Dagger 2实现动态更改url的HostSelectionInterceptor

dagger dagger-2 retrofit2 retrofit android

DolDurma · 技术社区 · 8 年前

我只是了解如何实施 Retrofit 使用Dagger2在该服务器上设置动态更改url reference

HostSelectionInterceptor 类在Dagger2上使用该选项,但我无法正确执行该选项,因此出现错误:

我的 NetworkModule

@Module(includes = ContextModule.class)
public class NetworkModule {
    @Provides
    @AlachiqApplicationScope
    public HttpLoggingInterceptor loggingInterceptor() {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
            @Override
            public void log(String message) {
                Timber.e(message);
            }
        });
        interceptor.setLevel(HttpLoggingInterceptor.Level.BASIC);
        return interceptor;
    }

    ...

    @Provides
    @AlachiqApplicationScope
    public HostSelectionInterceptor hostSelectionInterceptor() {
        return new HostSelectionInterceptor();
    }

    @Provides
    @AlachiqApplicationScope
    public OkHttpClient okHttpClient(HostSelectionInterceptor hostInterceptor, HttpLoggingInterceptor loggingInterceptor, Cache cache) {
        return new OkHttpClient.Builder()
                .addInterceptor(hostInterceptor)
                .addInterceptor(loggingInterceptor)
                .connectTimeout(30, TimeUnit.SECONDS)
                .writeTimeout(30, TimeUnit.SECONDS)
                .readTimeout(30, TimeUnit.SECONDS)
                .cache(cache)
                .build();
    }
}

和 主机选择接收器 模块:

@Module(includes = {NetworkModule.class})
public final class HostSelectionInterceptor implements Interceptor {
    private volatile String host;

    @Provides
    @AlachiqApplicationScope
    public String setHost(String host) {
        this.host = host;
        return this.host;
    }

    public String getHost() {
        return host;
    }

    @Provides
    @AlachiqApplicationScope
    @Override
    public okhttp3.Response intercept(Chain chain) {
        Request request = chain.request();
        String  host    = getHost();
        if (host != null) {
            HttpUrl newUrl = request.url().newBuilder()
                    .host(host)
                    .build();
            request = request.newBuilder()
                    .url(newUrl)
                    .build();
        }
        try {
            return chain.proceed(request);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }
}

http://myUrl.com/ 在okhttp3.HttpUrl$Builder.host(HttpUrl.java:754)

问题由主机设置 setHost 此代码行上的方法:

HttpUrl newUrl = request.url().newBuilder()
        .host(host)
        .build();

2 回复 | 直到 8 年前

EpicPandaForce Jigar Joshi 8 年前

基于 this github comment

        HttpUrl newUrl = request.url().newBuilder()
                .host(host)
                .build();

        HttpUrl newUrl = HttpUrl.parse(host);

Veton Neziri 5 年前

您应该像这样使用拦截器:

class HostSelectionInterceptor: Interceptor {
    override fun intercept(chain: Interceptor.Chain): Response {
        apiHost?.let { host ->
            val request = chain.request()
            val newUrl = request.url.newBuilder().host(host).build()
            val newRequest = request.newBuilder().url(newUrl).build()
            return chain.proceed(newRequest)
        }
        throw IOException("Unknown Server")
    }
}

You just need to change at runtime the apiHost variable (var apiHost = "example.com"). Then add this interceptor to OkHttpClient builder:

val okHttpClient = OkHttpClient.Builder()
    .addInterceptor(HostSelectionInterceptor())
    .build()