Java Singleton类代码示例

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
@NetworkInterceptor
Interceptor provideNetworkInterceptor() {
    return new Interceptor() {
        @Override
        public Response intercept(@NonNull Chain chain) throws IOException {
            Response originalResponse = chain.proceed(chain.request());
            String cacheControl = originalResponse.header("Cache-Control");
            if (cacheControl == null || cacheControl.contains("no-store") || cacheControl.contains("no-cache") ||
                    cacheControl.contains("must-revalidate") || cacheControl.contains("max-age=0")) {
                return originalResponse.newBuilder()
                        .removeHeader("Pragma")
                        .header("Cache-Control", "public, max-age=" + 86400)// cache and reuse for 1 day(86400 seconds)
                        .build();
            } else {
                return originalResponse;
            }
        }
    };
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Singleton
@Provides
HttpUrl provideBaseUrl() {
    if (mBaseUrl != null) {
        HttpUrl httpUrl = mBaseUrl.url();
        if (httpUrl != null) {
            return httpUrl;
        }
    }
    return mApiUrl == null ? HttpUrl.parse("https://api.github.com/") : mApiUrl;
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
static OkHttpClient provideOkHttpClient() {
  return new OkHttpClient.Builder()
      .readTimeout(DEFAULT_READ_TIMEOUT_SECONDS, TimeUnit.SECONDS)
      .connectTimeout(DEFAULT_CONNECT_TIMEOUT_SECONDS, TimeUnit.SECONDS)
      .addNetworkInterceptor(new StethoInterceptor())
      .build();
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Deployment
public static WebArchive createDeployment() {
    String url = SimpleGetApi.class.getName() + "/mp-rest/url=http://localhost:8080";
    String scope = SimpleGetApi.class.getName() + "/mp-rest/scope=" + Singleton.class.getName();
    JavaArchive jar = ShrinkWrap.create(JavaArchive.class)
        .addClasses(SimpleGetApi.class, MySingletonApi.class)
        .addAsManifestResource(new StringAsset(url + "\n" + scope), "microprofile-config.properties")
        .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml");
    return ShrinkWrap.create(WebArchive.class)
        .addAsLibrary(jar)
        .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml");
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
public Cache provideCache(@Named("cacheDir") File cacheDir, @Named("cacheSize") long cacheSize) {

    Cache cache = null;

    try {
        cache = new Cache(new File(cacheDir.getPath(), "http-cache"), cacheSize);
    } catch (Exception e) {
        e.printStackTrace();
    }

    return cache;
}
 

import javax.inject.Singleton; //导入依赖的package包/类
/**
 * 提供处理 RxJava 错误的管理器
 *
 * @return
 */
@Singleton
@Provides
RxErrorHandler proRxErrorHandler(Application application, ResponseErrorListener listener) {
    return RxErrorHandler
            .builder()
            .with(application)
            .responseErrorListener(listener)
            .build();
}
 

import javax.inject.Singleton; //导入依赖的package包/类
/**
 * 需要单独给RxCache提供缓存路径
 * 提供RxCache缓存地址
 */
@Singleton
@Provides
@Named("RxCacheDirectory")
File provideRxCacheDirectory(File cacheDir) {
    File cacheDirectory = new File(cacheDir, "RxCache");
    return DataHelper.makeDirs(cacheDirectory);
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
public Converter.Factory providesGsonConverterFactory() {
    Gson gson = new GsonBuilder()
            .registerTypeAdapterFactory(AutoValuesGsonAdapterFactory.create())
            .create();
    return GsonConverterFactory.create(gson);
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
static DataSource dataSource(DatabaseConfig config) {
  HikariConfig hikari = new HikariConfig();
  hikari.setJdbcUrl(config.getJdbcUrl());
  hikari.setUsername(config.getUsername());
  hikari.setPassword(config.getPassword());
  hikari.addDataSourceProperty("cachePrepStmts", "true");
  hikari.addDataSourceProperty(
      "statementInterceptors", "brave.mysql.TracingStatementInterceptor");
  hikari.addDataSourceProperty("useUnicode", "yes");
  hikari.setMetricsTrackerFactory(new PrometheusMetricsTrackerFactory());
  return new HikariDataSource(hikari);
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
Poller providePoller(@IoExecutor Executor ioExecutor,
		@Scheduler ScheduledExecutorService scheduler,
		ConnectionManager connectionManager,
		ConnectionRegistry connectionRegistry, PluginManager pluginManager,
		SecureRandom random, Clock clock, EventBus eventBus) {
	Poller poller = new Poller(ioExecutor, scheduler, connectionManager,
			connectionRegistry, pluginManager, random, clock);
	eventBus.addListener(poller);
	return poller;
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
OkHttpClient client() {
    return new OkHttpClient.Builder()
            .cache(new Cache(app.getCacheDir(), 1024L * 20))
            .followRedirects(true)
            .retryOnConnectionFailure(true)
            .build();
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Singleton
@Provides
ServerAPI provideServerAPI() {
    return new RestAdapter.Builder()
        .setEndpoint(ServerAPI.ENDPOINT)
        .setLogLevel(RestAdapter.LogLevel.FULL)
        .setLog(new RestAdapter.Log() {
            @Override
            public void log(String message) {
                v("Retrofit", message);
            }
        })
        .build().create(ServerAPI.class);
}
 

import javax.inject.Singleton; //导入依赖的package包/类
public static <T> Module proxyModule(Class<T> proxyInterface) {

		return new AbstractModule() {
			@Override
			protected void configure() {
				Provider<Queries> provider = getProvider(Queries.class);

				Multibinder<QueriesSource> sourcesBinder = Multibinder.newSetBinder(binder(), QueriesSource.class);
				sourcesBinder.addBinding().toInstance(QueriesSource.ofClass(proxyInterface));

				bind(proxyInterface).toProvider(new ProxyInterfaceProvider<T>(provider, proxyInterface))
						.in(Singleton.class);
			}
		};
	}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
OkHttpClient provideOkHttpClient() {
    OkHttpClient.Builder builder = new OkHttpClient.Builder()
            .connectTimeout(Config.CONNECT_TIMEOUT, SECONDS)
            .writeTimeout(Config.WRITE_TIMEOUT, SECONDS)
            .readTimeout(Config.READ_TIMEOUT, SECONDS);
    if (BuildConfig.DEBUG) {
        builder.addInterceptor(new HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY));
    }
    return builder.build();
}
 

import javax.inject.Singleton; //导入依赖的package包/类
@Provides
@Singleton
ObjectMapper provideObjectMapper() {
  ObjectMapper objectMapper = new ObjectMapper();

  objectMapper.setPropertyNamingStrategy(
      PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);
  objectMapper.setSerializationInclusion(JsonInclude.Include.NON_ABSENT);
  objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
  objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

  return objectMapper;
}