需要依赖jar: commons-codec.jar
beans64 工具类

package com.znsd.beans64;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

/**
 * beans64 工具类
 */
public class Base64Util {

    /**
     * 将文件转换 beans64
     * @param imgFile 待处理的数据
     * @return beans64数据
     */
    public static String filetoBese64(String dir) {
        InputStream in = null;
        byte[] bytes = null;
        try {
            in = new FileInputStream(dir);
            bytes = new byte[in.available()];
            in.read(bytes);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new String(Base64.encodeBase64(bytes));
    }
    
    /**
     * 将 beans64 数据转为 磁盘数据
     * @param beans64String
     * @param dir
     * @throws IOException
     */
    public static void bese64ToFile(String beans64String, String dir) throws IOException {
        if (beans64String == null) return ;

        byte[] bytes = Base64.decodeBase64(beans64String);
        for (int i = 0; i < bytes.length; ++i) {
            if (bytes[i] < 0) bytes[i] += 256;
        }

        OutputStream out = new FileOutputStream(dir);
        out.write(bytes);
        out.flush();
        out.close();
    }
    
    /**
     * 将String 数据转换为 beans64
     * @param beans64String 需要转换的 beans64
     * @return 处理好的 String
     */
    public static String stringTobeans64(String beans64String) {
        return new String(Base64.encodeBase64(beans64String.getBytes()));
    }
    
    /**
     * 将beans64 数据转换为 String
     * @param beans64String 需要转换的 beans64
     * @return 处理好的 String
     */
    public static String beans64ToString(String beans64String) {
        String temp = "";
        if (beans64String == null) return temp;

        byte[] bytes = Base64.decodeBase64(beans64String);
        for (int i = 0; i < bytes.length; ++i) {
            if (bytes[i] < 0) bytes[i] += 256;
        }
        return new String(bytes);
    }
    
}

/**
 * demo 案例
 * @param args
 */
public static void main(String[] args) {
    System.out.println(beans64ToString(stringTobeans64("StringData")));

    String fileBese64 = filetoBese64("c:/filePath");
    bese64ToFile(fileBese64, "toDir");
}

beans64 与 md5 整合: 个人觉得没必要了做加密 DM5 就够了

package com.znsd.beans64;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

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

/**
 * 消息摘要工具
 */
public class MessageDigestUtil {
    
    /**
     * 先进行MD5摘要再进行Base64编码获取摘要字符串
     *
     * @param str
     * @return
     */
    public static String base64AndMD5(String str) {
        if (str == null) {
            throw new IllegalArgumentException("inStr can not be null");
        }
        return base64AndMD5(toBytes(str));
    }

    /**
     * 先进行MD5摘要再进行Base64编码获取摘要字符串
     *
     * @return
     */
    public static String base64AndMD5(byte[] bytes) {
        if (bytes == null) {
            throw new IllegalArgumentException("bytes can not be null");
        }
        try {
            final MessageDigest md = MessageDigest.getInstance("MD5");
            md.reset();
            md.update(bytes);
            final Base64 base64 = new Base64();
            final byte[] enbytes = base64.encode(md.digest());
            return new String(enbytes);
        } catch (final NoSuchAlgorithmException e) {
            throw new IllegalArgumentException("unknown algorithm MD5");
        }
    }

    /**
     * UTF-8编码转换为ISO-9959-1
     *
     * @param str
     * @return
     */
    public static String utf8ToIso88591(String str) {
        if (str == null) {
            return str;
        }

        try {
            return new String(str.getBytes("UTF-8"), "ISO-8859-1");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    /**
     * ISO-9959-1编码转换为UTF-8
     *
     * @param str
     * @return
     */
    public static String iso88591ToUtf8(String str) {
        if (str == null) {
            return str;
        }

        try {
            return new String(str.getBytes("ISO-8859-1"), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    /**
     * String转换为字节数组
     *
     * @param str
     * @return
     */
    private static byte[] toBytes(final String str) {
        if (str == null) {
            return null;
        }
        return str.getBytes();
    }
}

MD5加密 与 SHA1加密

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

/**
 * MD5 案例
 * @param args
 */
public static void main(String[] args) {
    // 1. MD5加密 DigestUtils.md5Hex(data)
    System.out.println(DigestUtils.md5Hex("StringData"));
    // 2. SHA1加密 DigestUtils.sha1Hex(data)
    System.out.println(DigestUtils.sha1Hex("StringData"));
}