Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import java.security.MessageDigest;

public class Main {
    private final static String SHA1 = "SHA-1";
    public static final char HEX_DIGITS[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
            'e', 'f' };

    public static String getFileSHA1(File file) {
        return toHexString(getFileDigest(file, SHA1));
    }

    public static String toHexString(byte[] b) {
        StringBuilder sb = new StringBuilder(b.length * 2);
        for (int i = 0; i < b.length; i++) {
            sb.append(HEX_DIGITS[(b[i] & 0xf0) >>> 4]);
            sb.append(HEX_DIGITS[b[i] & 0x0f]);
        }
        return sb.toString();
    }

    public static byte[] getFileDigest(File file, String algorithm) {
        InputStream fis = null;
        byte[] buffer = new byte[1024];
        int numRead;
        MessageDigest md;
        try {
            fis = new FileInputStream(file);
            md = MessageDigest.getInstance(algorithm);
            while ((numRead = fis.read(buffer)) > 0) {
                md.update(buffer, 0, numRead);
            }
            fis.close();
            return md.digest();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                }
            }
        }
        return null;
    }
}