[干货] Android 常用开发工具类

在开发中使用一些工具类，能让代码更加简洁，开发效率也更高，下面是我收集的Android中常用的一些开发工具类，如果大家有更好的工具，欢迎私信我。

数据管理的工具类，清理缓存数据

import java.io.File;
import java.math.BigDecimal;

import android.content.Context;
import android.os.Environment;
import android.text.TextUtils;

/**
 * 本应用数据清除管理器
 * 
 * 
 */
public class DataCleanManager {
    /**
     * * 清除本应用内部缓存(/data/data/com.xxx.xxx/cache) * *
     * 
     * @param context
     */
    public static void cleanInternalCache(Context context) {
        deleteFilesByDirectory(context.getCacheDir());
    }

    /**
     * * 清除本应用所有数据库(/data/data/com.xxx.xxx/databases) * *
     * 
     * @param context
     */
    public static void cleanDatabases(Context context) {
        deleteFilesByDirectory(new File("/data/data/"
                + context.getPackageName() + "/databases"));
    }

    /**
     * * 清除本应用SharedPreference(/data/data/com.xxx.xxx/shared_prefs) *
     * 
     * @param context
     */
    public static void cleanSharedPreference(Context context) {
        deleteFilesByDirectory(new File("/data/data/"
                + context.getPackageName() + "/shared_prefs"));
    }

    /**
     * * 按名字清除本应用数据库 * *
     * 
     * @param context
     * @param dbName
     */
    public static void cleanDatabaseByName(Context context, String dbName) {
        context.deleteDatabase(dbName);
    }

    /**
     * * 清除/data/data/com.xxx.xxx/files下的内容 * *
     * 
     * @param context
     */
    public static void cleanFiles(Context context) {
        deleteFilesByDirectory(context.getFilesDir());
    }

    /**
     * * 清除外部cache下的内容(/mnt/sdcard/android/data/com.xxx.xxx/cache)
     * 
     * @param context
     */
    public static void cleanExternalCache(Context context) {
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            deleteFilesByDirectory(context.getExternalCacheDir());
        }
    }

    /**
     * * 清除自定义路径下的文件，使用需小心，请不要误删。而且只支持目录下的文件删除 * *
     * 
     * @param filePath
     * */
    public static void cleanCustomCache(String filePath) {
        deleteFilesByDirectory(new File(filePath));
    }

    /**
     * * 清除本应用所有的数据 * *
     * 
     * @param context
     * @param filepath
     */
    public static void cleanApplicationData(Context context, String... filepath) {
        cleanInternalCache(context);
        cleanExternalCache(context);
        cleanDatabases(context);
        cleanSharedPreference(context);
        cleanFiles(context);
        if (filepath == null) {
            return;
        }
        for (String filePath : filepath) {
            cleanCustomCache(filePath);
        }
    }

    /**
     * * 删除方法 这里只会删除某个文件夹下的文件，如果传入的directory是个文件，将不做处理 * *
     * 
     * @param directory
     */
    private static void deleteFilesByDirectory(File directory) {
        if (directory.isFile()) {
            directory.delete();
        } else if (directory != null && directory.exists()
                && directory.isDirectory()) {
            for (File item : directory.listFiles()) {
                deleteFilesByDirectory(item);
            }
        }
    }

    // 获取文件
    // Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/
    // 目录，一般放一些长时间保存的数据
    // Context.getExternalCacheDir() -->
    // SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据
    public static long getFolderSize(File file) throws Exception {
        long size = 0;
        try {
            File[] fileList = file.listFiles();
            for (int i = 0; i < fileList.length; i++) {
                // 如果下面还有文件
                if (fileList[i].isDirectory()) {
                    size = size + getFolderSize(fileList[i]);
                } else {
                    size = size + fileList[i].length();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return size;
    }

    /**
     * 删除指定目录下文件及目录
     * 
     * @param deleteThisPath
     * @param filepath
     * @return
     */
    public static void deleteFolderFile(String filePath, boolean deleteThisPath) {
        if (!TextUtils.isEmpty(filePath)) {
            try {
                File file = new File(filePath);
                if (file.isDirectory()) {// 如果下面还有文件
                    File files[] = file.listFiles();
                    for (int i = 0; i < files.length; i++) {
                        deleteFolderFile(files[i].getAbsolutePath(), true);
                    }
                }
                if (deleteThisPath) {
                    if (!file.isDirectory()) {// 如果是文件，删除
                        file.delete();
                    } else {// 目录
                        if (file.listFiles().length == 0) {// 目录下没有文件或者目录，删除
                            file.delete();
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 格式化单位
     * 
     * @param size
     * @return
     */
    public static String getFormatSize(double size) {
        double kiloByte = size / 1024;
        if (kiloByte < 1) {
            return size + "Byte";
        }

        double megaByte = kiloByte / 1024;
        if (megaByte < 1) {
            BigDecimal result1 = new BigDecimal(Double.toString(kiloByte));
            return result1.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "KB";
        }

        double gigaByte = megaByte / 1024;
        if (gigaByte < 1) {
            BigDecimal result2 = new BigDecimal(Double.toString(megaByte));
            return result2.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "MB";
        }

        double teraBytes = gigaByte / 1024;
        if (teraBytes < 1) {
            BigDecimal result3 = new BigDecimal(Double.toString(gigaByte));
            return result3.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "GB";
        }
        BigDecimal result4 = new BigDecimal(teraBytes);
        return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString()
                + "TB";
    }

    public static String getCacheSize(File file) throws Exception {
        return getFormatSize(getFolderSize(file));
    }

}

手机号，邮箱，身份证校验工具类

import java.util.HashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class VerificationUtils {

    private final static Pattern emailer = Pattern
            .compile("\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*");
    private static String _codeError;
    // wi =2(n-1)(mod 11)
    final static int[] wi = { 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4,
            2, 1 };
    // verify digit
    final static int[] vi = { 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2 };
    private static int[] ai = new int[18];
    private static String[] _areaCode = { "11", "12", "13", "14", "15", "21",
            "22", "23", "31", "32", "33", "34", "35", "36", "37", "41", "42",
            "43", "44", "45", "46", "50", "51", "52", "53", "54", "61", "62",
            "63", "64", "65", "71", "81", "82", "91" };
    private static HashMap<String, Integer> dateMap;
    private static HashMap<String, String> areaCodeMap;
    static {
        dateMap = new HashMap<String, Integer>();
        dateMap.put("01", 31);
        dateMap.put("02", null);
        dateMap.put("03", 31);
        dateMap.put("04", 30);
        dateMap.put("05", 31);
        dateMap.put("06", 30);
        dateMap.put("07", 31);
        dateMap.put("08", 31);
        dateMap.put("09", 30);
        dateMap.put("10", 31);
        dateMap.put("11", 30);
        dateMap.put("12", 31);
        areaCodeMap = new HashMap<String, String>();
        for (String code : _areaCode) {
            areaCodeMap.put(code, null);
        }
    }

    /**
     * 验证手机号
     * 
     * @param str
     * @return
     */
    public static boolean isMobile(String str) {
        Pattern p = null;
        Matcher m = null;
        boolean b = false;
        p = Pattern.compile("^[1][3,4,5,8,7][0-9]{9}$");
        // p = Pattern.compile("^((13[0-9])|(15[^4,\\D])|(18[0,5-9]))\\d{8}$");
        m = p.matcher(str);
        b = m.matches();
        return b;
    }

    /**
     * 验证邮箱
     * 
     * @param email
     * @return
     */
    public static boolean isEmail(String email) {
        if (email == null || email.trim().length() == 0)
            return false;
        return emailer.matcher(email).matches();
    }

    public static boolean isEmpty(String input) {
        if (input == null || "".equals(input))
            return true;

        for (int i = 0; i < input.length(); i++) {
            char c = input.charAt(i);
            if (c != ' ' && c != '\t' && c != '\r' && c != '\n') {
                return false;
            }
        }
        return true;
    }

    /**
     * 验证位数
     * @param code
     * @return
     */
    public static boolean verifyLength(String code) {
        int length = code.length();
        if (length == 15 || length == 18) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * 验证省区
     * @param code
     * @return
     */
    public static boolean verifyAreaCode(String code) {
        String areaCode = code.substring(0, 2);
        if (areaCodeMap.containsKey(areaCode)) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * 验证生日
     * @param code
     * @return
     */
    public static boolean verifyBirthdayCode(String code) {
        String month = code.substring(10, 12);
        boolean isEighteenCode = (18 == code.length());
        if (!dateMap.containsKey(month)) {
            return false;
        }
        String dayCode = code.substring(12, 14);
        Integer day = dateMap.get(month);
        String yearCode = code.substring(6, 10);
        Integer year = Integer.valueOf(yearCode);

        if (day != null) {
            if (Integer.valueOf(dayCode) > day || Integer.valueOf(dayCode) < 1) {
                return false;
            }
        } else {
            if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
                if (Integer.valueOf(dayCode) > 29
                        || Integer.valueOf(dayCode) < 1) {
                    return false;
                }
            } else {
                if (Integer.valueOf(dayCode) > 28
                        || Integer.valueOf(dayCode) < 1) {
                    return false;
                }
            }
        }
        return true;
    }

    public static boolean containsAllNumber(String code) {
        String str = "";
        if (code.length() == 15) {
            str = code.substring(0, 15);
        } else if (code.length() == 18) {
            str = code.substring(0, 17);
        }
        char[] ch = str.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            if (!(ch[i] >= '0' && ch[i] <= '9')) {
                return false;
            }
        }
        return true;
    }

    public static boolean verify(String idcard) {
        if (!verifyLength(idcard)) {
            return false;
        }
        if (!containsAllNumber(idcard)) {
            return false;
        }

        String eifhteencard = "";
        if (idcard.length() == 15) {
            eifhteencard = uptoeighteen(idcard);
        } else {
            eifhteencard = idcard;
        }
        if (!verifyAreaCode(eifhteencard)) {
            return false;
        }
        if (!verifyBirthdayCode(eifhteencard)) {
            return false;
        }
        if (!verifyMOD(eifhteencard)) {
            return false;
        }
        return true;
    }

    public static boolean verifyMOD(String code) {
        String verify = code.substring(17, 18);
        if ("x".equals(verify)) {
            code = code.replaceAll("x", "X");
            verify = "X";
        }
        String verifyIndex = getVerify(code);
        if (verify.equals(verifyIndex)) {
            return true;
        }
        // int x=17;
        // if(code.length()==15){
        // x=14;
        // }
        return false;
    }

    public static String getVerify(String eightcardid) {
        int remaining = 0;

        if (eightcardid.length() == 18) {
            eightcardid = eightcardid.substring(0, 17);
        }

        if (eightcardid.length() == 17) {
            int sum = 0;
            for (int i = 0; i < 17; i++) {
                String k = eightcardid.substring(i, i + 1);
                ai[i] = Integer.parseInt(k);
            }

            for (int i = 0; i < 17; i++) {
                sum = sum + wi[i] * ai[i];
            }
            remaining = sum % 11;
        }

        return remaining == 2 ? "X" : String.valueOf(vi[remaining]);
    }

    public static String uptoeighteen(String fifteencardid) {
        String eightcardid = fifteencardid.substring(0, 6);
        eightcardid = eightcardid + "19";
        eightcardid = eightcardid + fifteencardid.substring(6, 15);
        eightcardid = eightcardid + getVerify(eightcardid);
        return eightcardid;
    }
}

sharedPreferences封装工具类

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;

public class SharedPreferencesUtil {
    /**
     * 保存在手机里面的文件名
     */
    private static final String SP_NAME = "sp_name";

    public static void setStringParam(Context context, String key, String value) {
        SharedPreferences sp = context.getSharedPreferences(SP_NAME,
                Context.MODE_PRIVATE);
        Editor edit = sp.edit();
        edit.putString(key, value);
        edit.commit();
        key = null;
        value = null;
        edit = null;
        sp = null;
        context = null;
    }

    /**
     * 保存字符串数据类型
     * 
     * @param context
     * @param keys
     * @param values
     */
    public static void setStringParams(Context context, String[] keys,
            String[] values) {
        SharedPreferences sp = context.getSharedPreferences(SP_NAME,
                Context.MODE_PRIVATE);
        Editor edit = sp.edit();
        for (int i = 0; i < keys.length; i++) {
            edit.putString(keys[i], values[i]);
        }
        keys = null;
        values = null;
        edit.commit();
        edit = null;
        sp = null;
        context = null;
    }

    /**
     * 保存所有数据类型 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法
     * 
     * @param context
     * @param key
     * @param object
     */
    public static void setParam(Context context, String key, Object object) {

        String type = object.getClass().getSimpleName();
        SharedPreferences sp = context.getSharedPreferences(SP_NAME,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();

        if ("String".equals(type)) {
            editor.putString(key, (String) object);
        } else if ("Integer".equals(type)) {
            editor.putInt(key, (Integer) object);
        } else if ("Boolean".equals(type)) {
            editor.putBoolean(key, (Boolean) object);
        } else if ("Float".equals(type)) {
            editor.putFloat(key, (Float) object);
        } else if ("Long".equals(type)) {
            editor.putLong(key, (Long) object);
        }

        key = null;
        object = null;
        editor.commit();
        editor = null;
        sp = null;
        context = null;
    }

    /**
     * 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值
     * 
     * @param context
     * @param key
     * @param defaultObject
     * @return
     */
    public static Object getParam(Context context, String key,
            Object defaultObject) {
        String type = defaultObject.getClass().getSimpleName();
        SharedPreferences sp = context.getSharedPreferences(SP_NAME,
                Context.MODE_PRIVATE);

        if ("String".equals(type)) {
            return sp.getString(key, (String) defaultObject);
        } else if ("Integer".equals(type)) {
            return sp.getInt(key, (Integer) defaultObject);
        } else if ("Boolean".equals(type)) {
            return sp.getBoolean(key, (Boolean) defaultObject);
        } else if ("Float".equals(type)) {
            return sp.getFloat(key, (Float) defaultObject);
        } else if ("Long".equals(type)) {
            return sp.getLong(key, (Long) defaultObject);
        }

        return null;
    }

}

Service工具类

import java.util.List;

import android.app.ActivityManager;
import android.content.Context;

/**
 * 服务是否运行检测帮助类
 * 
 */
public class ServiceUtil {

    /**
     * 判断服务是否后台运行
     * 
     * @param context
     *            Context
     * @param className
     *            判断的服务名字
     * @return true 在运行 false 不在运行
     */
    public static boolean isServiceRun(Context mContext, String className) {
        boolean isRun = false;
        ActivityManager activityManager = (ActivityManager) mContext
                .getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningServiceInfo> serviceList = activityManager
                .getRunningServices(40);
        int size = serviceList.size();
        for (int i = 0; i < size; i++) {
            if (serviceList.get(i).service.getClassName().equals(className) == true) {
                isRun = true;
                break;
            }
        }
        return isRun;
    }

}

Log日志工具类

import android.util.Log;

/**
 * Log显示工具类
 */
public class LogUtil {

    /**
     * 开发
     */
    private final static int DEVELOP = 0;

    /**
     * 测试
     */
    private final static int TEST = 1;

    /**
     * 上线
     */
    private final static int ONLINE = 2;

    /**
     * 当前状态
     */
    private final static int NOWSTATE = DEVELOP;

    public static void info(String msg) {
        info("volunteer", msg);
    }

    public static void info(String TAG, String msg) {
        switch (NOWSTATE) {
        case DEVELOP:
            Log.i(TAG, "develop:---" + msg);
            break;
        case TEST:
            Log.i(TAG, "test:---" + msg);
            break;
        case ONLINE:

            break;

        }
    }
}

MD5 加密工具类

public final class MD5Utils {
    private static final char Digit[] = {
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
        'a', 'b', 'c', 'd', 'e', 'f'
    };
    private static final byte PADDING[] = {
        -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
        0, 0, 0, 0
    };
    private static long state[] = new long[4];
    private static long count[] = new long[2];
    private static byte buffer[] = new byte[64];
    private static String digestHexStr;
    private static byte digest[] = new byte[16];

    private MD5Utils() {
    }

    /**
     * 没有加盐 小写输出
     * @param s
     * @return
     */
    public static String toMD5(String s) {
        md5Init();
        md5Update(s.getBytes(), s.length());
        md5Final();
        digestHexStr = "";
        for(int i = 0; i < 16; i++)
            digestHexStr = digestHexStr + byteHEX(digest[i]);

        return digestHexStr;
    }

    private static void md5Init() {
        count[0] = 0L;
        count[1] = 0L;
        state[0] = 0x67452301L;
        state[1] = 0xefcdab89L;
        state[2] = 0x98badcfeL;
        state[3] = 0x10325476L;
    }

    private static long F(long x, long y, long z) {
        return (x & y) | ((~x) & z); 
    }

    private static long G(long x, long y, long z) {
        return (x & z) | (y & (~z)); 
    }

    private static long H(long x, long y, long z) {
        return x ^ y ^ z;
    }

    private static long I(long x, long y, long z) {
        return y ^ (x | (~z));
    }

    private static long FF(long l, long l1, long l2, long l3, 
            long l4, long l5, long l6) {
        l += F(l1, l2, l3) + l4 + l6;
        l = (int)l << (int)l5 | (int)l >>> (int)(32L - l5);
        l += l1;
        return l;
    }

    private static long GG(long l, long l1, long l2, long l3, 
            long l4, long l5, long l6) {
        l += G(l1, l2, l3) + l4 + l6;
        l = (int)l << (int)l5 | (int)l >>> (int)(32L - l5);
        l += l1;
        return l;
    }

    private static long HH(long l, long l1, long l2, long l3, 
            long l4, long l5, long l6) {
        l += H(l1, l2, l3) + l4 + l6;
        l = (int)l << (int)l5 | (int)l >>> (int)(32L - l5);
        l += l1;
        return l;
    }

    private static long II(long l, long l1, long l2, long l3, 
            long l4, long l5, long l6) {
        l += I(l1, l2, l3) + l4 + l6;
        l = (int)l << (int)l5 | (int)l >>> (int)(32L - l5);
        l += l1;
        return l;
    }

    private static void md5Update(byte abyte0[], int i) {
        byte abyte1[] = new byte[64];
        int k = (int)(count[0] >>> 3) & 0x3f;
        if ((count[0] += i << 3) < (long)(i << 3))
            count[1]++;
        count[1] += i >>> 29;
        int l = 64 - k;
        int j;
        if (i >= l) {
            md5Memcpy(buffer, abyte0, k, 0, l);
            md5Transform(buffer);
            for(j = l; j + 63 < i; j += 64) {
                md5Memcpy(abyte1, abyte0, 0, j, 64);
                md5Transform(abyte1);
            }
            k = 0;
        } else {
            j = 0;
        }
        md5Memcpy(buffer, abyte0, k, j, i - j);
    }

    private static void md5Final() {
        byte abyte0[] = new byte[8];
        Encode(abyte0, count, 8);
        int i = (int)(count[0] >>> 3) & 0x3f;
        int j = i >= 56 ? 120 - i : 56 - i;
        md5Update(PADDING, j);
        md5Update(abyte0, 8);
        Encode(digest, state, 16);
    }

    private static void md5Memcpy(byte abyte0[], byte abyte1[], int i, int j, int k) {
        for(int l = 0; l < k; l++)
            abyte0[i + l] = abyte1[j + l];
    }

    private static void md5Transform(byte abyte0[]) {
        long l = state[0];
        long l1 = state[1];
        long l2 = state[2];
        long l3 = state[3];
        long al[] = new long[16];
        Decode(al, abyte0, 64);
        l = FF(l, l1, l2, l3, al[0], 7L, 0xd76aa478L);
        l3 = FF(l3, l, l1, l2, al[1], 12L, 0xe8c7b756L);
        l2 = FF(l2, l3, l, l1, al[2], 17L, 0x242070dbL);
        l1 = FF(l1, l2, l3, l, al[3], 22L, 0xc1bdceeeL);
        l = FF(l, l1, l2, l3, al[4], 7L, 0xf57c0fafL);
        l3 = FF(l3, l, l1, l2, al[5], 12L, 0x4787c62aL);
        l2 = FF(l2, l3, l, l1, al[6], 17L, 0xa8304613L);
        l1 = FF(l1, l2, l3, l, al[7], 22L, 0xfd469501L);
        l = FF(l, l1, l2, l3, al[8], 7L, 0x698098d8L);
        l3 = FF(l3, l, l1, l2, al[9], 12L, 0x8b44f7afL);
        l2 = FF(l2, l3, l, l1, al[10], 17L, 0xffff5bb1L);
        l1 = FF(l1, l2, l3, l, al[11], 22L, 0x895cd7beL);
        l = FF(l, l1, l2, l3, al[12], 7L, 0x6b901122L);
        l3 = FF(l3, l, l1, l2, al[13], 12L, 0xfd987193L);
        l2 = FF(l2, l3, l, l1, al[14], 17L, 0xa679438eL);
        l1 = FF(l1, l2, l3, l, al[15], 22L, 0x49b40821L);
        l = GG(l, l1, l2, l3, al[1], 5L, 0xf61e2562L);
        l3 = GG(l3, l, l1, l2, al[6], 9L, 0xc040b340L);
        l2 = GG(l2, l3, l, l1, al[11], 14L, 0x265e5a51L);
        l1 = GG(l1, l2, l3, l, al[0], 20L, 0xe9b6c7aaL);
        l = GG(l, l1, l2, l3, al[5], 5L, 0xd62f105dL);
        l3 = GG(l3, l, l1, l2, al[10], 9L, 0x2441453L);
        l2 = GG(l2, l3, l, l1, al[15], 14L, 0xd8a1e681L);
        l1 = GG(l1, l2, l3, l, al[4], 20L, 0xe7d3fbc8L);
        l = GG(l, l1, l2, l3, al[9], 5L, 0x21e1cde6L);
        l3 = GG(l3, l, l1, l2, al[14], 9L, 0xc33707d6L);
        l2 = GG(l2, l3, l, l1, al[3], 14L, 0xf4d50d87L);
        l1 = GG(l1, l2, l3, l, al[8], 20L, 0x455a14edL);
        l = GG(l, l1, l2, l3, al[13], 5L, 0xa9e3e905L);
        l3 = GG(l3, l, l1, l2, al[2], 9L, 0xfcefa3f8L);
        l2 = GG(l2, l3, l, l1, al[7], 14L, 0x676f02d9L);
        l1 = GG(l1, l2, l3, l, al[12], 20L, 0x8d2a4c8aL);
        l = HH(l, l1, l2, l3, al[5], 4L, 0xfffa3942L);
        l3 = HH(l3, l, l1, l2, al[8], 11L, 0x8771f681L);
        l2 = HH(l2, l3, l, l1, al[11], 16L, 0x6d9d6122L);
        l1 = HH(l1, l2, l3, l, al[14], 23L, 0xfde5380cL);
        l = HH(l, l1, l2, l3, al[1], 4L, 0xa4beea44L);
        l3 = HH(l3, l, l1, l2, al[4], 11L, 0x4bdecfa9L);
        l2 = HH(l2, l3, l, l1, al[7], 16L, 0xf6bb4b60L);
        l1 = HH(l1, l2, l3, l, al[10], 23L, 0xbebfbc70L);
        l = HH(l, l1, l2, l3, al[13], 4L, 0x289b7ec6L);
        l3 = HH(l3, l, l1, l2, al[0], 11L, 0xeaa127faL);
        l2 = HH(l2, l3, l, l1, al[3], 16L, 0xd4ef3085L);
        l1 = HH(l1, l2, l3, l, al[6], 23L, 0x4881d05L);
        l = HH(l, l1, l2, l3, al[9], 4L, 0xd9d4d039L);
        l3 = HH(l3, l, l1, l2, al[12], 11L, 0xe6db99e5L);
        l2 = HH(l2, l3, l, l1, al[15], 16L, 0x1fa27cf8L);
        l1 = HH(l1, l2, l3, l, al[2], 23L, 0xc4ac5665L);
        l = II(l, l1, l2, l3, al[0], 6L, 0xf4292244L);
        l3 = II(l3, l, l1, l2, al[7], 10L, 0x432aff97L);
        l2 = II(l2, l3, l, l1, al[14], 15L, 0xab9423a7L);
        l1 = II(l1, l2, l3, l, al[5], 21L, 0xfc93a039L);
        l = II(l, l1, l2, l3, al[12], 6L, 0x655b59c3L);
        l3 = II(l3, l, l1, l2, al[3], 10L, 0x8f0ccc92L);
        l2 = II(l2, l3, l, l1, al[10], 15L, 0xffeff47dL);
        l1 = II(l1, l2, l3, l, al[1], 21L, 0x85845dd1L);
        l = II(l, l1, l2, l3, al[8], 6L, 0x6fa87e4fL);
        l3 = II(l3, l, l1, l2, al[15], 10L, 0xfe2ce6e0L);
        l2 = II(l2, l3, l, l1, al[6], 15L, 0xa3014314L);
        l1 = II(l1, l2, l3, l, al[13], 21L, 0x4e0811a1L);
        l = II(l, l1, l2, l3, al[4], 6L, 0xf7537e82L);
        l3 = II(l3, l, l1, l2, al[11], 10L, 0xbd3af235L);
        l2 = II(l2, l3, l, l1, al[2], 15L, 0x2ad7d2bbL);
        l1 = II(l1, l2, l3, l, al[9], 21L, 0xeb86d391L);
        state[0] += l;
        state[1] += l1;
        state[2] += l2;
        state[3] += l3;
    }

    private static void Encode(byte abyte0[], long al[], int i) {
        int j = 0;
        for(int k = 0; k < i; k += 4) {
            abyte0[k] = (byte)(int)(al[j] & 255L);
            abyte0[k + 1] = (byte)(int)(al[j] >>> 8 & 255L);
            abyte0[k + 2] = (byte)(int)(al[j] >>> 16 & 255L);
            abyte0[k + 3] = (byte)(int)(al[j] >>> 24 & 255L);
            j++;
        }
    }

    private static void Decode(long al[], byte abyte0[], int i) {
        int j = 0;
        for (int k = 0; k < i; k += 4) {
            al[j] = b2iu(abyte0[k]) | b2iu(abyte0[k + 1]) << 8 | b2iu(abyte0[k + 2]) << 16 | b2iu(abyte0[k + 3]) << 24;
            j++;
        }
    }

    private static long b2iu(byte byte0) {
        return byte0 >= 0 ? byte0 : byte0 & 0xff;
    }

    private static String byteHEX(byte byte0) {
        char ac[] = new char[2];
        ac[0] = Digit[byte0 >>> 4 & 0xf];
        ac[1] = Digit[byte0 & 0xf];
        return new String(ac);
    }

    public static void main(String[] args) {
        System.out.println(toMD5("123456"));
    }
}

可逆加密算法工具类

import java.io.UnsupportedEncodingException;

public class Base64Utils {
    private static char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D',
            'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
            'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
            'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',
            'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', '+', '/' };
    private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
            60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
            10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,
            -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
            38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,
            -1, -1 };

    /**
     * 加密
     * 
     * @param data
     * @return
     */
    public static String encode(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;
        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                        | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                    | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2)
                    | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }

    /**
     * 解密
     * 
     * @param str
     * @return
     */
    public static byte[] decode(String str) {
        try {
            return decodePrivate(str);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return new byte[] {};
    }

    private static byte[] decodePrivate(String str)
            throws UnsupportedEncodingException {
        StringBuffer sb = new StringBuffer();
        byte[] data = null;
        data = str.getBytes("US-ASCII");
        int len = data.length;
        int i = 0;
        int b1, b2, b3, b4;
        while (i < len) {

            do {
                b1 = base64DecodeChars[data[i++]];
            } while (i < len && b1 == -1);
            if (b1 == -1)
                break;

            do {
                b2 = base64DecodeChars[data[i++]];
            } while (i < len && b2 == -1);
            if (b2 == -1)
                break;
            sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

            do {
                b3 = data[i++];
                if (b3 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b3 = base64DecodeChars[b3];
            } while (i < len && b3 == -1);
            if (b3 == -1)
                break;
            sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

            do {
                b4 = data[i++];
                if (b4 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b4 = base64DecodeChars[b4];
            } while (i < len && b4 == -1);
            if (b4 == -1)
                break;
            sb.append((char) (((b3 & 0x03) << 6) | b4));
        }
        return sb.toString().getBytes("iso8859-1");
    }

}