如何在Android中使用setCache进行在线数据OkHttpClient

Question

我想表明3 fragments在我Activity和加载数据从json任何fragments!我需要将网站数据显示Recyclerview在OkHTTP v3库中.
我想将此数据显示为离线,我的意思是,如果用户关闭数据/ wifi,则显示此数据以供离线使用.但我不想使用SQLite数据库!
对于这个想法,我使用okHttpClient cache,但找不到setCache客户端,并告诉我这个错误:图像链接

MainActivity代码:

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private ArrayList<AndroidVersion> data;
    private DataAdapter adapter;
    private static Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;

        initViews();
    }

    private void initViews() {
        recyclerView = (RecyclerView) findViewById(R.id.card_recycler_view);
        recyclerView.setHasFixedSize(true);
        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(layoutManager);
        loadJSON();
    }

    private void loadJSON() {

        OkHttpClient client = new OkHttpClient();
        client.networkInterceptors().add(REWRITE_CACHE_CONTROL_INTERCEPTOR);

        //setup cache
        File httpCacheDirectory = new File(context.getCacheDir(), "responses");
        int cacheSize = 10 * 1024 * 1024; // 10 MiB
        Cache cache = new Cache(httpCacheDirectory, cacheSize);

        //add cache to the client
        client.setCache(cache);

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://api.learn2crack.com")
                .client(client)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        RequestInterface request = retrofit.create(RequestInterface.class);
        Call<JSONResponse> call = request.getJSON();
        call.enqueue(new Callback<JSONResponse>() {
            @Override
            public void onResponse(Call<JSONResponse> call, Response<JSONResponse> response) {

                JSONResponse jsonResponse = response.body();
                data = new ArrayList<>(Arrays.asList(jsonResponse.getAndroid()));
                adapter = new DataAdapter(data);
                recyclerView.setAdapter(adapter);
            }

            @Override
            public void onFailure(Call<JSONResponse> call, Throwable t) {
                Log.d("Error", t.getMessage());
            }
        });
    }

    private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {
        @Override
        public okhttp3.Response intercept(Chain chain) throws IOException {
            okhttp3.Response originalResponse = chain.proceed(chain.request());
            if (isNetworkAvailable(context)) {
                int maxAge = 60; // read from cache for 1 minute
                return originalResponse.newBuilder()
                        .header("Cache-Control", "public, max-age=" + maxAge)
                        .build();
            } else {
                int maxStale = 60 * 60 * 24 * 28; // tolerate 4-weeks stale
                return originalResponse.newBuilder()
                        .header("Cache-Control", "public, only-if-cached, max-stale=" + maxStale)
                        .build();
            }
        }
    };

    public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager cm =
                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null &&
                activeNetwork.isConnectedOrConnecting();
    }

}

我该如何解决这个问题并使用okHttpClient缓存？

Answer 1

从截图中可以看出,您使用的是OkHttp的过时版本.Retrofit 2需要OkHttp 3.(最新版权为3.4.1.)

另外,要在OkHttp 3中设置客户端上的缓存,new OkHttpClient.Builder().cache(cache).build().