base64code.java

这是一个获取文件MD5码的JAVA程序。可以用于学习JAVA

package com.md5.chen;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.digest.DigestUtils;



import java.io.*;
import java.security.DigestInputStream;
import java.security.MessageDigest;

//获取BASE64编码的文件MD5
public class Base64Code
{
	private Base64Code()
	{

	}

	public static byte[] encode(byte[] buf)
	{
		if (buf == null)
		{
			return encode(buf, 0, 0);
		} else
		{
			return encode(buf, 0, buf.length);
		}
	}

	// 将 buf 进行 BASE64 编码
	public static byte[] encode(byte[] buf, int pos, int length)
	{
		byte[] result = null;

		if (length > 0)
		{
			if (pos == 0 && buf.length == length)
			{
				return Base64.encodeBase64(buf);
			} else
			{
				byte[] newbuf = new byte[length];
				System.arraycopy(buf, pos, newbuf, 0, length);
				result = Base64.encodeBase64(newbuf);
			}
		}
		return result;
	}

	// 将 BASE64 编码的字符串 buf 进行解码
	public static byte[] decode(byte[] buf, int pos, int length)
			throws IOException
	{
		byte[] result = null;

		if (length > 0)
		{
			result = FastBase64.decodeBase64(buf, pos, length);

			// if (pos == 0 && buf.length == length) {
			// result = Base64.decodeBase64(buf);
			// } else {
			// byte[] newbuf = new byte[length];
			// System.arraycopy(buf, pos, newbuf, 0, length);
			// result = Base64.decodeBase64(newbuf);
			// }
		}

		return result;
	}
	
	public static void main(String[] args)
	{
		BufferedReader reader = new BufferedReader(new InputStreamReader(
				System.in));
		String PATH="";
		String md5String="";
		byte k[]=null;
		System.out.println("输入文件路径:");
		try
		{
			PATH = reader.readLine();// 将主目录路径保存再PATH中

		} catch (IOException e)
		{
			e.toString();
		}
		try
		{ // 生成MessageDigest对象MD
			MessageDigest md = MessageDigest.getInstance("MD5");
			FileInputStream fin = new FileInputStream(PATH);
			DigestInputStream din = new DigestInputStream(fin, md);

			while (din.read() != -1)
			{
				;
			}
			// 计算MD5 并进行BASE64编码
			 md5String = new String(Base64Code.encode(md.digest()));
			
		} catch (Exception e)
		{
			e.toString();
		}
        
		System.out.println("BASE64-MD5:"+md5String);
		
	
		

	}
}