Android中Rxjava实现三级缓存的两种方式

/** * Created by wukewei on 16/6/20. */public class BehaviorSubjectFragment extends BaseFragment {  public static BehaviorSubjectFragment newInstance() {    BehaviorSubjectFragment fragment = new BehaviorSubjectFragment();    return fragment;  }  String diskData = null;  String networkData = "从服务器获取的数据";  BehaviorSubject<String> cache;  View mView;  @Nullable  @Override  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {    mView = inflater.inflate(R.layout.fragment_content, container, false);    init();    return mView;  }  private void init() {    mView.findViewById(R.id.get).setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        subscriptionData(new Observer<String>() {          @Override          public void onCompleted() {          }          @Override          public void onError(Throwable e) {          }          @Override          public void onNext(String s) {            Log.d("onNext", s);          }        });      }    });    mView.findViewById(R.id.memory).setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        BehaviorSubjectFragment.this.cache = null;      }    });    mView.findViewById(R.id.memory_disk).setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        BehaviorSubjectFragment.this.cache = null;        BehaviorSubjectFragment.this.diskData = null;      }    });  }  private void loadNewWork() {    Observable<String> o = Observable.just(networkData)        .doOnNext(new Action1<String>() {          @Override          public void call(String s) {            BehaviorSubjectFragment.this.diskData = s;            Log.d("写入磁盘", "写入磁盘");          }        });    o.subscribe(new Action1<String>() {      @Override      public void call(String s) {        cache.onNext(s);      }    }, new Action1<Throwable>() {      @Override      public void call(Throwable throwable) {      }    });  }  private Subscription subscriptionData(@NonNull Observer<String> observer) {    if (cache == null) {      cache = BehaviorSubject.create();      Observable.create(new Observable.OnSubscribe<String>() {        @Override        public void call(Subscriber<? super String> subscriber) {          String data = diskData;          if (data == null) {            Log.d("来自网络", "来自网络");            loadNewWork();          } else {            Log.d("来自磁盘", "来自磁盘");            subscriber.onNext(data);          }        }      })          .subscribeOn(Schedulers.io())          .subscribe(cache);    } else {      Log.d("来自内存", "来自内存");    }    return cache.observeOn(AndroidSchedulers.mainThread()).subscribe(observer);  }}

/** * Created by wukewei on 16/6/19. */public interface ICache {  <T> Observable<T> get(String key, Class<T> cls);  <T> void put(String key, T t);}

/** * Created by wukewei on 16/6/19. */public class MemoryCache implements ICache{  private LruCache<String, String> mCache;  public MemoryCache() {    final int maxMemory = (int) Runtime.getRuntime().maxMemory();    final int cacheSize = maxMemory / 8;    mCache = new LruCache<String, String>(cacheSize) {      @Override      protected int sizeOf(String key, String value) {        try {          return value.getBytes("UTF-8").length;        } catch (UnsupportedEncodingException e) {          e.printStackTrace();          return value.getBytes().length;        }      }    };  }  @Override  public <T> Observable<T> get(final String key, final Class<T> cls) {    return Observable.create(new Observable.OnSubscribe<T>() {      @Override      public void call(Subscriber<? super T> subscriber) {        String result = mCache.get(key);        if (subscriber.isUnsubscribed()) {          return;        }        if (TextUtils.isEmpty(result)) {          subscriber.onNext(null);        } else {          T t = new Gson().fromJson(result, cls);          subscriber.onNext(t);        }        subscriber.onCompleted();      }    });  }  @Override  public <T> void put(String key, T t) {    if (null != t) {      mCache.put(key, new Gson().toJson(t));    }  }  public void clearMemory(String key) {    mCache.remove(key);  }}

/** * Created by wukewei on 16/6/19. */public class DiskCache implements ICache{  private static final String NAME = ".db";  public static long OTHER_CACHE_TIME = 10 * 60 * 1000;  public static long WIFI_CACHE_TIME = 30 * 60 * 1000;  File fileDir;  public DiskCache() {    fileDir = CacheLoader.getApplication().getCacheDir();  }  @Override  public <T> Observable<T> get(final String key, final Class<T> cls) {    return Observable.create(new Observable.OnSubscribe<T>() {      @Override      public void call(Subscriber<? super T> subscriber) {        T t = (T) getDiskData1(key + NAME);        if (subscriber.isUnsubscribed()) {          return;        }        if (t == null) {          subscriber.onNext(null);        } else {          subscriber.onNext(t);        }        subscriber.onCompleted();      }    })        .subscribeOn(Schedulers.io())        .observeOn(AndroidSchedulers.mainThread());  }  @Override  public <T> void put(final String key, final T t) {    Observable.create(new Observable.OnSubscribe<T>() {      @Override      public void call(Subscriber<? super T> subscriber) {        boolean isSuccess = isSave(key + NAME, t);        if (!subscriber.isUnsubscribed() && isSuccess) {          subscriber.onNext(t);          subscriber.onCompleted();        }      }    })        .subscribeOn(Schedulers.io())        .observeOn(AndroidSchedulers.mainThread())        .subscribe();  }  /**   * 保存数据   */  private <T> boolean isSave(String fileName, T t) {    File file = new File(fileDir, fileName);    ObjectOutputStream objectOut = null;    boolean isSuccess = false;    try {      FileOutputStream out = new FileOutputStream(file);          objectOut = new ObjectOutputStream(out);      objectOut.writeObject(t);      objectOut.flush();      isSuccess=true;    } catch (IOException e) {      Log.e("写入缓存错误",e.getMessage());    } catch (Exception e) {      Log.e("写入缓存错误",e.getMessage());    } finally {      closeSilently(objectOut);    }    return isSuccess;  }  /**   * 获取保存的数据   */  private Object getDiskData1(String fileName) {    File file = new File(fileDir, fileName);    if (isCacheDataFailure(file)) {      return null;    }    if (!file.exists()) {      return null;    }    Object o = null;    ObjectInputStream read = null;    try {      read = new ObjectInputStream(new FileInputStream(file));      o = read.readObject();    } catch (StreamCorruptedException e) {      Log.e("读取错误", e.getMessage());    } catch (IOException e) {      Log.e("读取错误", e.getMessage());    } catch (ClassNotFoundException e) {      Log.e("错误", e.getMessage());    } finally {      closeSilently(read);    }    return o;  }  private void closeSilently(Closeable closeable) {    if (closeable != null) {      try {        closeable.close();      } catch (Exception ignored) {      }    }  }  /**   * 判断缓存是否已经失效   */  private boolean isCacheDataFailure(File dataFile) {    if (!dataFile.exists()) {      return false;    }    long existTime = System.currentTimeMillis() - dataFile.lastModified();    boolean failure = false;    if (NetWorkUtil.getNetworkType(CacheLoader.getApplication()) == NetWorkUtil.NETTYPE_WIFI) {      failure = existTime > WIFI_CACHE_TIME ? true : false;    } else {      failure = existTime > OTHER_CACHE_TIME ? true : false;    }    return failure;  }  public void clearDisk(String key) {    File file = new File(fileDir, key + NAME);    if (file.exists()) file.delete();  }}

/** * Created by wukewei on 16/6/19. */public class CacheLoader {  private static Application application;  public static Application getApplication() {    return application;  }  private ICache mMemoryCache, mDiskCache;  private CacheLoader() {    mMemoryCache = new MemoryCache();    mDiskCache = new DiskCache();  }  private static CacheLoader loader;  public static CacheLoader getInstance(Context context) {    application = (Application) context.getApplicationContext();    if (loader == null) {      synchronized (CacheLoader.class) {        if (loader == null) {          loader = new CacheLoader();        }      }    }    return loader;  }  public <T> Observable<T> asDataObservable(String key, Class<T> cls, NetworkCache<T> networkCache) {    Observable observable = Observable.concat(        memory(key, cls),        disk(key, cls),        network(key, cls, networkCache))        .first(new Func1<T, Boolean>() {          @Override          public Boolean call(T t) {            return t != null;          }        });    return observable;  }  private <T> Observable<T> memory(String key, Class<T> cls) {    return mMemoryCache.get(key, cls).doOnNext(new Action1<T>() {      @Override      public void call(T t) {        if (null != t) {          Log.d("我是来自内存","我是来自内存");        }      }    });  }  private <T> Observable<T> disk(final String key, Class<T> cls) {    return mDiskCache.get(key, cls)        .doOnNext(new Action1<T>() {          @Override          public void call(T t) {            if (null != t) {              Log.d("我是来自磁盘","我是来自磁盘");              mMemoryCache.put(key, t);            }          }        });  }  private <T> Observable<T> network(final String key, Class<T> cls      , NetworkCache<T> networkCache) {    return networkCache.get(key, cls)        .doOnNext(new Action1<T>() {          @Override          public void call(T t) {            if (null != t) {              Log.d("我是来自网络","我是来自网络");              mDiskCache.put(key, t);              mMemoryCache.put(key, t);            }          }        });  }  public void clearMemory(String key) {    ((MemoryCache)mMemoryCache).clearMemory(key);  }  public void clearMemoryDisk(String key) {    ((MemoryCache)mMemoryCache).clearMemory(key);    ((DiskCache)mDiskCache).clearDisk(key);  }}

/** * Created by wukewei on 16/6/19. */public abstract class NetworkCache<T> {  public abstract Observable<T> get(String key, final Class<T> cls);}

/** * Created by wukewei on 16/5/30. */public class ItemPresenter extends BasePresenter<ItemContract.View> implements ItemContract.Presenter {  private static final String key = "new_list";  protected int pn = 1;  protected void replacePn() {    pn = 1;  }  private boolean isRefresh() {    return pn == 1;  }  private NetworkCache<ListPopular> networkCache;  public ItemPresenter(Activity activity, ItemContract.View view) {    super(activity, view);  }  @Override  public void getListData(String type) {    if (isRefresh()) mView.showLoading();    networkCache = new NetworkCache<ListPopular>() {      @Override      public Observable<ListPopular> get(String key, Class<ListPopular> cls) {        return mHotApi.getPopular(ItemPresenter.this.pn, Constants.PAGE_SIZE, type)            .compose(SchedulersCompat.applyIoSchedulers())            .compose(RxResultHelper.handleResult())            .flatMap(populars -> {              ListPopular popular = new ListPopular(populars);              return Observable.just(popular);            });      }    };    Subscription subscription = CacheLoader.getInstance(mActivity)        .asDataObservable(key + type + ItemPresenter.this.pn, ListPopular.class, networkCache)        .map(listPopular -> listPopular.data)        .subscribe(populars -> {          mView.showContent();          if (isRefresh()) {            if (populars.size() == 0) mView.showNotdata();            mView.addRefreshData(populars);          } else {            mView.addLoadMoreData(populars);          }        }, throwable -> {          if (isRefresh())          mView.showError(ErrorHanding.handleError(throwable));          handleError(throwable);        });    addSubscrebe(subscription);  }}