Java Code Examples for org.iq80.leveldb.DB#get()

The following examples show how to use org.iq80.leveldb.DB#get() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: LevelDBManager.java    From nuls with MIT License 6 votes vote down vote up 
/**
 * 弃用的方法/Deprecated method
 */
@Deprecated
public static byte[] get(String area, String key) {
    if (!baseCheckArea(area)) {
        return null;
    }
    if (StringUtils.isBlank(key)) {
        return null;
    }
    try {
        DB db = AREAS.get(area);
        return db.get(bytes(key));
    } catch (Exception e) {
        return null;
    }
}
Example 2
Source File: LevelDBManager.java    From nuls with MIT License 6 votes vote down vote up 
public static <T> T getModel(String area, byte[] key, Class<T> clazz) {
    if (!baseCheckArea(area)) {
        return null;
    }
    if (key == null) {
        return null;
    }
    try {
        DB db = AREAS.get(area);
        byte[] bytes = db.get(key);
        if (bytes == null) {
            return null;
        }
        RuntimeSchema schema = SCHEMA_MAP.get(ModelWrapper.class);
        ModelWrapper model = new ModelWrapper();
        ProtostuffIOUtil.mergeFrom(bytes, model, schema);
        if (clazz != null && model.getT() != null) {
            return clazz.cast(model.getT());
        }
        return (T) model.getT();
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}
Example 3
Source File: LevelDBManager.java    From nuls with MIT License 5 votes vote down vote up 
public static byte[] get(String area, byte[] key) {
    if (!baseCheckArea(area)) {
        return null;
    }
    if (key == null) {
        return null;
    }
    try {
        DB db = AREAS.get(area);
        return db.get(key);
    } catch (Exception e) {
        return null;
    }
}
Example 4
Source File: ReaderWithOffsets.java    From distributedlog with Apache License 2.0 4 votes vote down vote up 
public static void main(String[] args) throws Exception {
    if (4 != args.length) {
        System.out.println(HELP);
        return;
    }

    String dlUriStr = args[0];
    final String streamName = args[1];
    final String readerId = args[2];
    final String offsetStoreFile = args[3];

    URI uri = URI.create(dlUriStr);
    DistributedLogConfiguration conf = new DistributedLogConfiguration();
    Namespace namespace = NamespaceBuilder.newBuilder()
            .conf(conf)
            .uri(uri)
            .build();

    // open the dlm
    System.out.println("Opening log stream " + streamName);
    DistributedLogManager dlm = namespace.openLog(streamName);

    // open the offset store
    Options options = new Options();
    options.createIfMissing(true);
    final DB offsetDB = factory.open(new File(offsetStoreFile), options);
    final AtomicReference<DLSN> lastDLSN = new AtomicReference<DLSN>(null);
    // offset updater
    final ScheduledExecutorService executorService =
            Executors.newSingleThreadScheduledExecutor();
    executorService.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            if (null != lastDLSN.get()) {
                offsetDB.put(readerId.getBytes(UTF_8), lastDLSN.get().serializeBytes());
                System.out.println("Updated reader " + readerId + " offset to " + lastDLSN.get());
            }
        }
    }, 10, 10, TimeUnit.SECONDS);
    try {
        byte[] offset = offsetDB.get(readerId.getBytes(UTF_8));
        DLSN dlsn;
        if (null == offset) {
            dlsn = DLSN.InitialDLSN;
        } else {
            dlsn = DLSN.deserializeBytes(offset);
        }
        readLoop(dlm, dlsn, lastDLSN);
    } finally {
        offsetDB.close();
        dlm.close();
        namespace.close();
    }
}
Example 5
Source File: ReaderWithOffsets.java    From distributedlog with Apache License 2.0 4 votes vote down vote up 
public static void main(String[] args) throws Exception {
    if (4 != args.length) {
        System.out.println(HELP);
        return;
    }

    String dlUriStr = args[0];
    final String streamName = args[1];
    final String readerId = args[2];
    final String offsetStoreFile = args[3];

    URI uri = URI.create(dlUriStr);
    DistributedLogConfiguration conf = new DistributedLogConfiguration();
    DistributedLogNamespace namespace = DistributedLogNamespaceBuilder.newBuilder()
            .conf(conf)
            .uri(uri)
            .build();

    // open the dlm
    System.out.println("Opening log stream " + streamName);
    DistributedLogManager dlm = namespace.openLog(streamName);

    // open the offset store
    Options options = new Options();
    options.createIfMissing(true);
    final DB offsetDB = factory.open(new File(offsetStoreFile), options);
    final AtomicReference<DLSN> lastDLSN = new AtomicReference<DLSN>(null);
    // offset updater
    final ScheduledExecutorService executorService =
            Executors.newSingleThreadScheduledExecutor();
    executorService.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            if (null != lastDLSN.get()) {
                offsetDB.put(readerId.getBytes(UTF_8), lastDLSN.get().serializeBytes());
                System.out.println("Updated reader " + readerId + " offset to " + lastDLSN.get());
            }
        }
    }, 10, 10, TimeUnit.SECONDS);
    try {
        byte[] offset = offsetDB.get(readerId.getBytes(UTF_8));
        DLSN dlsn;
        if (null == offset) {
            dlsn = DLSN.InitialDLSN;
        } else {
            dlsn = DLSN.deserializeBytes(offset);
        }
        readLoop(dlm, dlsn, lastDLSN);
    } finally {
        offsetDB.close();
        dlm.close();
        namespace.close();
    }
}