字符串解密加密

调用如下：

Des3.encode(String str);//对字符串str加密Des3.decode(String str);//对字符串str解密

Des3.java

import java.security.Key;import javax.crypto.Cipher;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESedeKeySpec;import javax.crypto.spec.IvParameterSpec;/** * 3DES加密工具类 */public class Des3 {    // 密钥    private static String secretKey = "123123123123";//自定义    // 向量    private final static String iv = "123";//自定义    // 加解密统一使用的编码方式    private final static String encoding = "utf-8";    static Des3 des3;    private Des3() {    }    public static Des3 getDes3() {    if (null == des3) {        des3 = new Des3();    }    return des3;    }    public void setDecryptKey(String key) {        this.secretKey = key;    }    /**     * 3DES加密     *      * @param plainText     *            普通文本     * @return     * @throws Exception     */    public static String encode(String plainText) {        Key deskey = null;        DESedeKeySpec spec = null;        SecretKeyFactory keyfactory = null;        Cipher cipher = null;        byte[] encryptData = null;        try {            spec = new DESedeKeySpec(secretKey.getBytes());            keyfactory = SecretKeyFactory.getInstance("desede");            deskey = keyfactory.generateSecret(spec);            cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");            IvParameterSpec ips = new IvParameterSpec(iv.getBytes());            cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);            encryptData = cipher.doFinal(plainText.getBytes(encoding));        } catch (Exception e) {            e.printStackTrace();        }        return Base64.encode(encryptData);    }    /**     * 3DES解密     *      * @param encryptText     *            加密文本     * @return     */    public static String decode(String encryptText) throws Exception {        Key deskey = null;        DESedeKeySpec spec = null;        SecretKeyFactory keyfactory;        Cipher cipher = null;        byte[] decryptData = null;        spec = new DESedeKeySpec(secretKey.getBytes());        keyfactory = SecretKeyFactory.getInstance("desede");        deskey = keyfactory.generateSecret(spec);        cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");        IvParameterSpec ips = new IvParameterSpec(iv.getBytes());        cipher.init(Cipher.DECRYPT_MODE, deskey, ips);        decryptData = cipher.doFinal(Base64.decode(encryptText));        return new String(decryptData, encoding);    }}

Base64.java

import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.OutputStream;/** * Base64编码工具类 */public class Base64 {    private static final char[] legalChars =                  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();    public static String encode(byte[] data) {        int start = 0;        int len = data.length;        StringBuffer buf = new StringBuffer(data.length * 3 / 2);        int end = len - 3;        int i = start;        int n = 0;        while (i <= end) {            int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff)                                        << 8) | (((int) data[i + 2]) & 0x0ff);            buf.append(legalChars[(d >> 18) & 63]);            buf.append(legalChars[(d >> 12) & 63]);            buf.append(legalChars[(d >> 6) & 63]);            buf.append(legalChars[d & 63]);            i += 3;            if (n++ >= 14) {            n = 0;            buf.append(" ");            }        }        if (i == start + len - 2) {            int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);            buf.append(legalChars[(d >> 18) & 63]);            buf.append(legalChars[(d >> 12) & 63]);            buf.append(legalChars[(d >> 6) & 63]);            buf.append("=");        } else if (i == start + len - 1) {            int d = (((int) data[i]) & 0x0ff) << 16;            buf.append(legalChars[(d >> 18) & 63]);            buf.append(legalChars[(d >> 12) & 63]);            buf.append("==");        }        return buf.toString();    }    private static int decode(char c) {        if (c >= 'A' && c <= 'Z')            return ((int) c) - 65;        else if (c >= 'a' && c <= 'z')            return ((int) c) - 97 + 26;        else if (c >= '0' && c <= '9')            return ((int) c) - 48 + 26 + 26;        else            switch (c) {            case '+':            return 62;            case '/':            return 63;            case '=':            return 0;            default:            throw new RuntimeException("unexpected code: " + c);        }    }    /**     * Decodes the given Base64 encoded String to a new byte array. The byte     * array holding the decoded data is returned.     */    public static byte[] decode(String s) {        ByteArrayOutputStream bos = new ByteArrayOutputStream();        try {            decode(s, bos);        } catch (IOException e) {            throw new RuntimeException();        }        byte[] decodedBytes = bos.toByteArray();        try {            bos.close();            bos = null;        } catch (IOException ex) {            System.err.println("Error while decoding BASE64: " + ex.toString());        }        return decodedBytes;    }    private static void decode(String s, OutputStream os) throws IOException {        int i = 0;        int len = s.length();        while (true) {            while (i < len && s.charAt(i) <= ' ')            i++;            if (i == len)            break;            int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) +                       (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));            os.write((tri >> 16) & 255);            if (s.charAt(i + 2) == '=')            break;            os.write((tri >> 8) & 255);            if (s.charAt(i + 3) == '=')            break;            os.write(tri & 255);            i += 4;        }    }}