Java SHA1 computeSha1(ReadableByteChannel channel)

Description

compute Sha

License

Open Source License

Declaration

public static String computeSha1(ReadableByteChannel channel)
            throws IOException 

Method Source Code

//package com.java2s;
import java.io.IOException;

import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    private static final char[] HEX_CODE = "0123456789abcdef".toCharArray();

    public static String computeSha1(ReadableByteChannel channel)
            throws IOException {
        final MessageDigest sha1 = newSHA1();
        final ByteBuffer buf = ByteBuffer.allocate(8192);
        while (channel.read(buf) != -1) {
            buf.flip();//w ww.jav  a2s.  c  om
            sha1.update(buf);
            buf.clear();
        }
        return toHexString(ByteBuffer.wrap(sha1.digest()));
    }

    public static MessageDigest newSHA1() {
        try {
            return MessageDigest.getInstance("SHA-1");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("SHA-1");
        }
    }

    public static String toHexString(ByteBuffer buffer) {
        final StringBuilder r = new StringBuilder(buffer.remaining() * 2);
        while (buffer.hasRemaining()) {
            final byte b = buffer.get();
            r.append(HEX_CODE[(b >> 4) & 0xF]);
            r.append(HEX_CODE[(b & 0xF)]);
        }
        return r.toString();
    }
}

Related

1. computeSHA1(byte[] ba)
2. computeSha1(byte[] data)
3. computeSHA1(ByteBuffer convertme, int offset, int len)
4. computeSha1AsHexString(String strToHash)
5. computeSHA1Hash(byte[] data)
6. digestSHA1(byte[] data)
7. digestSHA1(String data)