com.google.protobuf.CodedInputStream# readString ( ) 源码实例Demo

/**
 * Cheap test to see if input stream is a wallet. This checks for a magic value at the beginning of the stream.
 *
 * @param is input stream to test
 * @return true if input stream is a wallet
 */
public static boolean isWallet(InputStream is) {
    try {
        final CodedInputStream cis = CodedInputStream.newInstance(is);
        final int tag = cis.readTag();
        final int field = WireFormat.getTagFieldNumber(tag);
        if (field != 1) // network_identifier
            return false;
        final String network = cis.readString();
        return NetworkParameters.fromID(network) != null;
    } catch (IOException x) {
        return false;
    }
}
 

/**
 * Cheap test to see if input stream is a wallet. This checks for a magic value at the beginning of the stream.
 *
 * @param is
 *            input stream to test
 * @return true if input stream is a wallet
 */
public static boolean isWallet(InputStream is) {
    try {
        final CodedInputStream cis = CodedInputStream.newInstance(is);
        final int tag = cis.readTag();
        final int field = WireFormat.getTagFieldNumber(tag);
        if (field != 1) // network_identifier
            return false;
        final String network = cis.readString();
        return NetworkParameters.fromID(network) != null;
    } catch (IOException x) {
        return false;
    }
}
 

/**
 * Cheap test to see if input stream is a wallet. This checks for a magic value at the beginning of the stream.
 *
 * @param is
 *            input stream to test
 * @return true if input stream is a wallet
 */
public static boolean isWallet(InputStream is) {
    try {
        final CodedInputStream cis = CodedInputStream.newInstance(is);
        final int tag = cis.readTag();
        final int field = WireFormat.getTagFieldNumber(tag);
        if (field != 1) // network_identifier
            return false;
        final String network = cis.readString();
        return NetworkParameters.fromID(network) != null;
    } catch (IOException x) {
        return false;
    }
}
 

public String deserialize(ByteBuffer byteBuffer) {
    CodedInputStream is = CodedInputStream.newInstance(byteBuffer.array());
    try {
        byte type = is.readRawByte();
        if (type == STRING) {
            return is.readString();
        } else {
            throw new IOException("Unexpected first byte. Expected '4' (string). Got '" + type + "'.");
        }
    } catch (IOException e) {
        throw new RuntimeException("IOException during deserialization", e);
    }
}
 

/**
 * Read a field of any primitive type for immutable messages from a CodedInputStream. Enums, groups, and embedded
 * messages are not handled by this method.
 *
 * @param input The stream from which to read.
 * @param type Declared type of the field.
 * @param checkUtf8 When true, check that the input is valid utf8.
 * @return An object representing the field's value, of the exact type which would be returned by
 *         {@link Message#getField(Descriptors.FieldDescriptor)} for this field.
 * @throws IOException Signals that an I/O exception has occurred.
 */
public static Object readPrimitiveField(CodedInputStream input, final WireFormat.FieldType type, boolean checkUtf8)
        throws IOException {
    switch (type) {
        case DOUBLE:
            return input.readDouble();
        case FLOAT:
            return input.readFloat();
        case INT64:
            return input.readInt64();
        case UINT64:
            return input.readUInt64();
        case INT32:
            return input.readInt32();
        case FIXED64:
            return input.readFixed64();
        case FIXED32:
            return input.readFixed32();
        case BOOL:
            return input.readBool();
        case STRING:
            if (checkUtf8) {
                return input.readStringRequireUtf8();
            } else {
                return input.readString();
            }
        case BYTES:
            return input.readByteArray();
        case UINT32:
            return input.readUInt32();
        case SFIXED32:
            return input.readSFixed32();
        case SFIXED64:
            return input.readSFixed64();
        case SINT32:
            return input.readSInt32();
        case SINT64:
            return input.readSInt64();

        case GROUP:
            throw new IllegalArgumentException("readPrimitiveField() cannot handle nested groups.");
        case MESSAGE:
            throw new IllegalArgumentException("readPrimitiveField() cannot handle embedded messages.");
        case ENUM:
            // We don't handle enums because we don't know what to do if the
            // value is not recognized.
            throw new IllegalArgumentException("readPrimitiveField() cannot handle enums.");
    }

    throw new RuntimeException("There is no way to get here, but the compiler thinks otherwise.");
}
 

@Override
public String deserialize(DeserializationContext context, CodedInputStream codedIn)
    throws IOException {
  return codedIn.readString();
}
 

@Override
public String deserialize(DeserializationContext context, CodedInputStream codedIn)
    throws IOException {
  Preconditions.checkState(!deserializationCalled.getAndSet(true));
  return codedIn.readString();
}
 

private BluefloodTimerRollup deserializeTimer(CodedInputStream in, byte timerVersion) throws IOException {
    // note: type and version have already been read.
    final double sum;
    if (timerVersion == VERSION_1_TIMER) {
        sum = in.readRawVarint64();
    } else if (timerVersion == VERSION_2_TIMER) {
        sum = in.readDouble();
    } else {
        throw new SerializationException(String.format("Unexpected timer deserialization version: %d", (int)timerVersion));
    }

    final long count = in.readRawVarint64();
    final double countPs = in.readDouble();
    final int sampleCount = in.readRawVarint32();

    // average
    byte statType = in.readRawByte();
    Average average = new Average();
    averageStatDeSer.deserialize(average, in);

    // max
    statType = in.readRawByte();
    MaxValue maxValue = new MaxValue();
    maxStatDeSer.deserialize(maxValue, in);

    // min
    statType = in.readRawByte();
    MinValue minValue = new MinValue();
    minStatDeSer.deserialize(minValue, in);

    // var
    statType = in.readRawByte();
    Variance variance = new Variance();
    varianceStatDeSer.deserialize(variance, in);

    BluefloodTimerRollup rollup = new BluefloodTimerRollup()
            .withSum(sum)
            .withCount(count)
            .withCountPS(countPs)
            .withSampleCount(sampleCount)
            .withAverage(average)
            .withMaxValue(maxValue)
            .withMinValue(minValue)
            .withVariance(variance);

    int numPercentiles = in.readRawVarint32();
    for (int i = 0; i < numPercentiles; i++) {
        String name = in.readString();
        Number mean = getUnversionedDoubleOrLong(in);
        rollup.setPercentile(name, mean);
    }

    return rollup;
}