作为我们这一行，最重要的就是保护数据。。。所以，在接受服务端的数据或者传送过去的时候，我们都要保护好·自己的数据，这样起步，谁也不伤害谁！嘿嘿。。。
然后自己这里呢，有一个的demo，这样是吧加密提取出来的，然后想要用，随时可以用就ok！
这是base64：
package com.android.utills; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; public class Base64 { private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" .toCharArray(); /** * data[]进行编码 * * @param data * @return */ 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; } } }
这是DES：
package com.android.utills; import javax.crypto.Cipher; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; /** * DES加密工具类 */ public class DesUtil { private static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 }; public static String encryptDES(String encryptString, String encryptKey) throws Exception { // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]); IvParameterSpec zeroIv = new IvParameterSpec(iv); SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES"); Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv); byte[] encryptedData = cipher.doFinal(encryptString.getBytes()); return Base64.encode(encryptedData); } public static String decryptDES(String decryptString, String decryptKey) throws Exception { byte[] byteMi = new Base64().decode(decryptString); IvParameterSpec zeroIv = new IvParameterSpec(iv); // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]); SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES"); Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, key, zeroIv); byte decryptedData[] = cipher.doFinal(byteMi); return new String(decryptedData); } /* * private static final String ENCRYPT_TYPE = "DES"; private static String * defaultKey = "";// 字符串默认键值 private Cipher encryptCipher = null;// 加密工具 * private Cipher decryptCipher = null;// 解密工具 * * public DesUtil() throws Exception { this(defaultKey); } *//** * 指定密钥构造方法 * * @param strKey * 指定的密钥 * @throws Exception */ /* * public DesUtil(String strKey) throws Exception { Security.addProvider(new * com.sun.crypto.provider.SunJCE()); Key key = getKey(strKey.getBytes()); * encryptCipher = Cipher.getInstance(ENCRYPT_TYPE); * encryptCipher.init(Cipher.ENCRYPT_MODE, key); decryptCipher = * Cipher.getInstance(ENCRYPT_TYPE); decryptCipher.init(Cipher.DECRYPT_MODE, * key); } *//** * 加密字节数组 * * @param arr * 需加密的字节数组 * @return 加密后的字节数组 * @throws Exception */ /* * private byte[] encryptStr(byte[] arr) throws Exception { return * encryptCipher.doFinal(arr); } *//** * 加密字符串 * * @param strIn * 需加密的字符串 * @return 加密后的字符串 * @throws Exception */ /* * public String encrypt(String strIn) throws Exception { return * StrConvertUtil.byteArrToHexStr(encryptStr(strIn.getBytes())); } *//** * 解密字节数组 * * @param arr * 需解密的字节数组 * @return 解密后的字节数组 * @throws Exception */ /* * private byte[] decryptStr(byte[] arr) throws Exception { return * decryptCipher.doFinal(arr); } *//** * 解密字符串 * * @param strIn * 需解密的字符串 * @return 解密后的字符串 * @throws Exception */ /* * public String decrypt(String strIn) throws Exception { return new * String(decryptStr(StrConvertUtil.hexStrToByteArr(strIn))); } *//** * 从指定字符串生成密钥，密钥所需的字节数组长度为8位。不足8位时后面补0，超出8位只取前8位 * * @param arrBTmp * 构成该字符串的字节数组 * @return 生成的密钥 */ /* * private Key getKey(byte[] arrBTmp) { byte[] arrB = new byte[8];// * 创建一个空的8位字节数组（默认值为0） // 将原始字节数组转换为8位 for (int i = 0; i < arrBTmp.length && * i < arrB.length; i++) { arrB[i] = arrBTmp[i]; } Key key = new * javax.crypto.spec.SecretKeySpec(arrB, ENCRYPT_TYPE);// 生成密钥 return key; } */ }
这是MD5：
package com.android.utills; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; /** * MD5加密工具类 * */ public class Md5Util { /** * 根据输入的字符串生成固定的32位MD5码 * * @param str * 输入的字符串 * @return MD5码 */ public final static String getMd5(String str) { MessageDigest mdInst = null; try { mdInst = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } mdInst.update(str.getBytes());// 使用指定的字节更新摘要 byte[] md = mdInst.digest();// 获得密文 return StrConvertUtil.byteArrToHexStr(md); } }
这是转换：
package com.android.utills; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; /** * MD5加密工具类 * */ public class Md5Util { /** * 根据输入的字符串生成固定的32位MD5码 * * @param str * 输入的字符串 * @return MD5码 */ public final static String getMd5(String str) { MessageDigest mdInst = null; try { mdInst = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } mdInst.update(str.getBytes());// 使用指定的字节更新摘要 byte[] md = mdInst.digest();// 获得密文 return StrConvertUtil.byteArrToHexStr(md); } }
okay、。。
当然，这里还有提供详细加密的路径链接：
http://apprentice.blog.51cto.com/2214645/1381824
http://hi.baidu.com/cuihenrychl/item/751966f0c31e310acf9f32e4?qq-pf-to=pcqq.c2c
原文：http://www.cnblogs.com/Catherine-Brain/p/3740961.html