MD5信息摘要

java 代码

import java.io.FileInputStream;
import java.security.MessageDigest;


/**
 *
 * @author: fanzhi_kong
 * @version MD5Demo V1.0
 * @date:  2007 May 31, 2007 10:10:35 AM
 *
 */
public class MD5 {

    static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
            'a', 'b', 'c', 'd', 'e', 'f' };

    /**生成字符串的MD5码
     *
     * @param s
     * @return
     */
    public final static String getMD5(String s) {
        try {
            byte[] strTemp = s.getBytes();
            MessageDigest md = MessageDigest.getInstance("MD5");

            md.update(strTemp);
            return digest(md);
        } catch (Exception e) {
            System.out.println("Error:"+e.getMessage());
            return null;
        }
    }



    /**生成文件的MD5
     *
     * @param path 文件完整路径
     * @return
     */
    public final static String getMD5File(String path) {
        try {
            MessageDigest mDigest = MessageDigest.getInstance("MD5");

            // 读取文件
            final int SIZE = 1024;
            FileInputStream in = new FileInputStream(path);
            byte[] buff = new byte[SIZE];
            int len;
            while ((len = in.read(buff)) != -1) {
                mDigest.update(buff, 0, len);
            }
            in.close();
            return digest(mDigest);

        } catch (Exception e) {
            System.out.println("error:"+e.getMessage());
            return null;
        }

    }


    /**计算摘要
     *
     * @param mDigest
     * @return
     */
    private static String digest(MessageDigest mDigest) {
        byte[] md = mDigest.digest();
        int j = md.length;
        char str[] = new char[j * 2];
        int k = 0;
        for (int i = 0; i < j; i++) {
            byte byte0 = md[i];
            str[k++] = hexDigits[byte0 >>> 4 & 0xf];
            str[k++] = hexDigits[byte0 & 0xf];
        }
        return new String(str);
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // System.out.println(MD5.getMD5("astro123456"));
        // System.out.println(MD5.getMD5("123456"));

        String path = "C:/tdemo.log";
        String path1 = "C:/tdemo1.log";
        String path2 = "C:/ftpupload/越狱111.rmvb";
         System.out.println(MD5.getMD5File(path));
          System.out.println(MD5.getMD5File(path1));
        long beginTime = System.currentTimeMillis();
        System.out.println(MD5.getMD5File(path2));
        long endTime = System.currentTimeMillis() - beginTime;
        System.out.println("计算时间为：" + endTime / 1000 + " s");

    }

}

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• 2007-05-31 10:31
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