Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.io.File;
import java.io.FileInputStream;

import java.io.UnsupportedEncodingException;

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

public class Main {

    public static synchronized boolean downloadFileMD5Check(File f, String expectedMD5) {
        boolean flag = false;
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            FileInputStream fis = new FileInputStream(f);
            byte[] b = new byte[1024];
            int len = 0;
            while ((len = fis.read(b)) != -1) {
                md.update(b, 0, len);
            }

            if (md5(md).equals(expectedMD5)) {
                flag = true;
            }
            fis.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return flag;
    }

    public static synchronized String md5(MessageDigest md5) {
        StringBuffer strBuf = new StringBuffer();
        byte[] result16 = md5.digest();
        char[] digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
        for (int i = 0; i < result16.length; i++) {
            char[] c = new char[2];
            c[0] = digit[result16[i] >>> 4 & 0x0f];
            c[1] = digit[result16[i] & 0x0f];
            strBuf.append(c);
        }

        return strBuf.toString();
    }

    public static String md5(String string) {
        if (isEmptyStr(string)) {
            return "";
        }
        try {
            return getMD5(string.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    public static boolean isEmptyStr(String str) {
        if (str == null || str.trim().length() == 0) {
            return true;
        } else {
            return false;
        }
    }

    private static String getMD5(byte[] source) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            StringBuffer result = new StringBuffer();
            for (byte b : md5.digest(source)) {
                result.append(Integer.toHexString((b & 0xf0) >>> 4));
                result.append(Integer.toHexString(b & 0x0f));
            }
            return result.toString();
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    @SuppressWarnings("finally")
    public static String getMD5(String str) {
        StringBuffer strBuf = new StringBuffer();
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(str.getBytes());
            byte[] result16 = md.digest();
            char[] digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
            for (int i = 0; i < result16.length; i++) {
                char[] c = new char[2];
                c[0] = digit[result16[i] >>> 4 & 0x0f];
                c[1] = digit[result16[i] & 0x0f];
                strBuf.append(c);
            }
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } finally {
            return strBuf.toString();
        }
    }
}