org.apache.hadoop.hbase.protobuf.ProtobufUtil#toScan ( )源码实例Demo

@Override
public void readFields(DataInput input) throws IOException {
    int count = WritableUtils.readVInt(input);
    scans = Lists.newArrayListWithExpectedSize(count);
    for (int i = 0; i < count; i++) {
        byte[] protoScanBytes = new byte[WritableUtils.readVInt(input)];
        input.readFully(protoScanBytes);
        ClientProtos.Scan protoScan = ClientProtos.Scan.parseFrom(protoScanBytes);
        Scan scan = ProtobufUtil.toScan(protoScan);
        scans.add(scan);
    }
    init();
}
 

@Override
public void write(DataOutput output) throws IOException {
    Preconditions.checkNotNull(scans);
    WritableUtils.writeVInt(output, scans.size());
    for (Scan scan : scans) {
        ClientProtos.Scan protoScan = ProtobufUtil.toScan(scan);
        byte[] protoScanBytes = protoScan.toByteArray();
        WritableUtils.writeVInt(output, protoScanBytes.length);
        output.write(protoScanBytes);
    }
}
 

@Override
public void readFields(DataInput input) throws IOException {
    regionLocation = WritableUtils.readString(input);
    regionSize = WritableUtils.readVLong(input);
    int count = WritableUtils.readVInt(input);
    scans = Lists.newArrayListWithExpectedSize(count);
    for (int i = 0; i < count; i++) {
        byte[] protoScanBytes = new byte[WritableUtils.readVInt(input)];
        input.readFully(protoScanBytes);
        ClientProtos.Scan protoScan = ClientProtos.Scan.parseFrom(protoScanBytes);
        Scan scan = ProtobufUtil.toScan(protoScan);
        scans.add(scan);
    }
    init();
}
 

@Override
public void write(DataOutput output) throws IOException {
    WritableUtils.writeString(output, regionLocation);
    WritableUtils.writeVLong(output, regionSize);

    Preconditions.checkNotNull(scans);
    WritableUtils.writeVInt(output, scans.size());
    for (Scan scan : scans) {
        ClientProtos.Scan protoScan = ProtobufUtil.toScan(scan);
        byte[] protoScanBytes = protoScan.toByteArray();
        WritableUtils.writeVInt(output, protoScanBytes.length);
        output.write(protoScanBytes);
    }
}
 

@Override
public DataScan readScan(ObjectInput in) throws IOException{
    byte[] bytes = new byte[in.readInt()];
    in.readFully(bytes);
    ClientProtos.Scan scan=ClientProtos.Scan.parseFrom(bytes);
    return new HScan(ProtobufUtil.toScan(scan));
}
 

@Override
protected DataScan readScan(ObjectInput in) throws IOException{
    byte[] bytes = new byte[in.readInt()];
    in.readFully(bytes);
    ClientProtos.Scan scan=ClientProtos.Scan.parseFrom(bytes);
    return new HScan(ProtobufUtil.toScan(scan));
}
 

/**
 * Setup scan condition if necessary.
 * 
 * @param conf
 * @param line
 * @throws IOException
 */
public static void setScanIfNecessary(Configuration conf, CommandLine line) throws IOException {
	String startRow = line.getOptionValue("startRow");
	String endRow = line.getOptionValue("endRow");
	String startTime = line.getOptionValue("startTime");
	String endTime = line.getOptionValue("endTime");

	boolean enabledScan = false;
	Scan scan = new Scan();
	// Row
	if (isNotBlank(startRow)) {
		conf.set(TableInputFormat.SCAN_ROW_START, startRow);
		scan.setStartRow(Bytes.toBytes(startRow));
		enabledScan = true;
	}
	if (isNotBlank(endRow)) {
		Assert2.hasText(startRow, "Argument for startRow and endRow are used simultaneously");
		conf.set(TableInputFormat.SCAN_ROW_STOP, endRow);
		scan.setStopRow(Bytes.toBytes(endRow));
		enabledScan = true;
	}

	// Row TimeStamp
	if (isNotBlank(startTime) && isNotBlank(endTime)) {
		conf.set(TableInputFormat.SCAN_TIMERANGE_START, startTime);
		conf.set(TableInputFormat.SCAN_TIMERANGE_END, endTime);
		try {
			Timestamp stime = new Timestamp(Long.parseLong(startTime));
			Timestamp etime = new Timestamp(Long.parseLong(endTime));
			scan.setTimeRange(stime.getTime(), etime.getTime());
			enabledScan = true;
		} catch (Exception e) {
			throw new IllegalArgumentException(String.format("Illegal startTime(%s) and endTime(%s)", startTime, endTime), e);
		}
	}

	if (enabledScan) {
		ClientProtos.Scan proto = ProtobufUtil.toScan(scan);
		log.info("All other SCAN configuration are ignored if\n"
				+ "		 * this is specified.See TableMapReduceUtil.convertScanToString(Scan)\n"
				+ "		 * for more details.");
		conf.set(TableInputFormat.SCAN, Base64.encodeBytes(proto.toByteArray()));
	}
}
 

private void readObject(ObjectInputStream in) throws IOException {
  this.configuration = SerializableCoder.of(SerializableConfiguration.class).decode(in).get();
  this.tableId = StringUtf8Coder.of().decode(in);
  this.scan = ProtobufUtil.toScan(ClientProtos.Scan.parseDelimitedFrom(in));
}
 

public static ClientProtos.Scan toPBScan(Scan scan) throws IOException {
    return ProtobufUtil.toScan(scan);
}
 

public static Scan fromPBScan(ClientProtos.Scan scan) throws IOException {
    return ProtobufUtil.toScan(scan);
}
 

public static ClientProtos.Scan toPBScan(Scan scan) throws IOException {
    return ProtobufUtil.toScan(scan);
}
 

/**
 * Writes the given scan into a Base64 encoded string.
 *
 * @param scan  The scan to write out.
 * @return The scan saved in a Base64 encoded string.
 * @throws IOException When writing the scan fails.
 */
static String convertScanToString(Scan scan) throws IOException {
    ClientProtos.Scan proto = ProtobufUtil.toScan(scan);
    return Base64.encodeBytes(proto.toByteArray());
}
 

/**
 *
 * @param scan
 * @return
 */
public static Scan fromPBScan(ClientProtos.Scan scan) throws IOException {
    return ProtobufUtil.toScan(scan);
}
 

/**
 * Converts the given Base64 string back into a Scan instance.
 *
 * @param base64  The scan details.
 * @return The newly created Scan instance.
 * @throws IOException When reading the scan instance fails.
 */
public static Scan convertStringToScan(String base64) throws IOException{
    byte[] bytes= Base64.getDecoder().decode(base64);
    ClientProtos.Scan scan=ClientProtos.Scan.parseFrom(bytes);
    return ProtobufUtil.toScan(scan);
}