Example usage for com.google.common.io CountingInputStream mark

Introduction

In this page you can find the example usage for com.google.common.io CountingInputStream mark.

Prototype

long mark

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Usage

From source file:org.archive.io.GZIPMembersInputStream.java

/**
 * A CountingInputStream is inserted to read compressed-offsets. 
 * //  ww  w. j  a va2 s . c om
 * @param in stream to wrap
 * @param lookback tolerance of initial mark
 * @return original stream wrapped in CountingInputStream
 * @throws IOException
 */
protected static InputStream countingStream(InputStream in, int lookback) throws IOException {
    CountingInputStream cin = new CountingInputStream(in);
    cin.mark(lookback);
    return cin;
}

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From source file:org.echocat.marquardt.common.Validator.java

/**
 * Deserializes and validates signed Signables.
 *
 * @param content Serialized Signable including Signature.
 * @param signableDeserializingFactory Factory to deserialize Signable with.
 * @param publicKeyProvider to return matching public key for given signable.
 * @param <T> Type of your Signable. Also Certificate uses this.
 * @return Deserialized and validated Signable.
 *
 * @throws SignatureValidationFailedException If the signature cannot be read or no key is provided to check.
 * @throws IllegalArgumentException when Signable cannot be deserialized from content using the provided factory or
 * no Signature can be extracted from provided content.
 *///from  w ww  .j a va2s  . c  om
@Nonnull
public <T extends Signable> T deserializeAndValidate(final byte[] content,
        final DeserializingFactory<T> signableDeserializingFactory,
        final Function<T, PublicKey> publicKeyProvider) {
    final ByteArrayInputStream inputStream = new ByteArrayInputStream(content);
    try {
        final CountingInputStream bufferedInputStream = new CountingInputStream(inputStream);
        try {
            bufferedInputStream.mark(0);
            final T signable = signableDeserializingFactory.consume(bufferedInputStream);

            final byte[] signableBytes = readSignableBytesAgainForLaterValidation(bufferedInputStream);

            final PublicKey publicKey = publicKeyProvider.apply(signable);
            if (publicKey == null) {
                throw new SignatureValidationFailedException("no public key provided");
            }
            final int signatureLength = InputStreamUtils.readInt(bufferedInputStream);
            final Signature signature = new Signature(
                    InputStreamUtils.readBytes(bufferedInputStream, signatureLength));
            if (signature.isValidFor(signableBytes, publicKey)) {
                return signable;
            }
            throw new SignatureValidationFailedException("signature is invalid for provided public key");
        } finally {
            IOUtils.closeQuietly(bufferedInputStream);
        }
    } catch (final IOException e) {
        throw new IllegalArgumentException("Signable cannot be deserialized using "
                + signableDeserializingFactory.getClass() + " or content is wrong / contains no signature.", e);
    } finally {
        IOUtils.closeQuietly(inputStream);
    }
}

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