【java】加密方式

Java代码

1. /**
2. * String Utility Class This is used to encode passwords programmatically
3. *
4. * <p>
5. * <a h ref="StringUtil.java.html"><i>View Source</i></a>
6. * </p>
7. *
8. * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a>
9. */
10. public class PasswordMD5Encryption {
11. // ~ Static fields/initializers
12. private static Logger logger = Logger.getLogger(PasswordMD5Encryption.class);
13. private final static Log log = LogFactory
14. .getLog(PasswordMD5Encryption.class);
15.  
16. // ~ Methods
17. /**
18. * Encode a string using algorithm specified in web.xml and return the
19. * resulting encrypted password. If exception, the plain credentials string
20. * is returned
21. *
22. * @param password
23. * Password or other credentials to use in authenticating this
24. * username
25. * @param algorithm
26. * Algorithm used to do the digest
27. *
28. * @return encypted password based on the algorithm.
29. */
30. public static String encodePassword(String password, String algorithm) {
31. byte[] unencodedPassword = password.getBytes();
32.  
33. MessageDigest md = null;
34.  
35. try {
36. // first create an instance, given the provider
37. md = MessageDigest.getInstance(algorithm);
38. } catch (Exception e) {
39. log.error("Exception: " + e);
40.  
41. return password;
42. }
43.  
44. md.reset();
45.  
46. // call the update method one or more times
47. // (useful when you don't know the size of your data, eg. stream)
48. md.update(unencodedPassword);
49.  
50. // now calculate the hash
51. byte[] encodedPassword = md.digest();
52.  
53. StringBuffer buf = new StringBuffer();
54.  
55. for (int i = 0; i < encodedPassword.length; i++) {
56. if ((encodedPassword[i] & 0xff) < 0x10) {
57. buf.append("0");
58. }
59.  
60. buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
61. }
62.  
63. return buf.toString();
64. }
65.  
66. /**
67. * Encode a string using Base64 encoding. Used when storing passwords as
68. * cookies.
69. *
70. * This is weak encoding in that anyone can use the decodeString routine to
71. * reverse the encoding.
72. *
73. * @param str
74. * @return String
75. */
76. public static String encodeString(String str) {
77. sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
78. return encoder.encodeBuffer(str.getBytes()).trim();
79. }
80.  
81. /**
82. * Decode a string using Base64 encoding.
83. * @param str
84. * @return String
85. */
86. public static String decodeString(String str) {
87. sun.misc.BASE64Decoder dec = new sun.misc.BASE64Decoder();
88. try {
89. return new String(dec.decodeBuffer(str));
90. } catch (IOException io) {
91. throw new RuntimeException(io.getMessage(), io.getCause());
92. }
93. }
94.  
95. public static void main(String[] args) {
96. String passString = "123456";
97. String newpass = PasswordMD5Encryption.encodeString(passString);
98. System.out.println(passString+" 加密后的字符串是 : " + newpass);
99. String newpassAgin = PasswordMD5Encryption.decodeString(newpass);
100. System.out.println(newpass+" 加密后再解密的字符串是 : " + newpassAgin);
101. }
102. }

/**
 * String Utility Class This is used to encode passwords programmatically
 * 
 * <p>
 * <a h ref="StringUtil.java.html"><i>View Source</i></a>
 * </p>
 * 
 * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a>
 */
public class PasswordMD5Encryption {
	// ~ Static fields/initializers
	private static Logger logger  = Logger.getLogger(PasswordMD5Encryption.class);
	private final static Log log = LogFactory
			.getLog(PasswordMD5Encryption.class);

	// ~ Methods
	/**
	 * Encode a string using algorithm specified in web.xml and return the
	 * resulting encrypted password. If exception, the plain credentials string
	 * is returned
	 * 
	 * @param password
	 *            Password or other credentials to use in authenticating this
	 *            username
	 * @param algorithm
	 *            Algorithm used to do the digest
	 * 
	 * @return encypted password based on the algorithm.
	 */
	public static String encodePassword(String password, String algorithm) {
		byte[] unencodedPassword = password.getBytes();

		MessageDigest md = null;

		try {
			// first create an instance, given the provider
			md = MessageDigest.getInstance(algorithm);
		} catch (Exception e) {
			log.error("Exception: " + e);

			return password;
		}

		md.reset();

		// call the update method one or more times
		// (useful when you don't know the size of your data, eg. stream)
		md.update(unencodedPassword);

		// now calculate the hash
		byte[] encodedPassword = md.digest();

		StringBuffer buf = new StringBuffer();

		for (int i = 0; i < encodedPassword.length; i++) {
			if ((encodedPassword[i] & 0xff) < 0x10) {
				buf.append("0");
			}

			buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
		}

		return buf.toString();
	}

	/**
	 * Encode a string using Base64 encoding. Used when storing passwords as
	 * cookies.
	 * 
	 * This is weak encoding in that anyone can use the decodeString routine to
	 * reverse the encoding.
	 * 
	 * @param str
	 * @return String
	 */
	public static String encodeString(String str) {
		sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
		return encoder.encodeBuffer(str.getBytes()).trim();
	}

	/**
	 * Decode a string using Base64 encoding.
	 * @param str
	 * @return String
	 */
	public static String decodeString(String str) {
		sun.misc.BASE64Decoder dec = new sun.misc.BASE64Decoder();
		try {
			return new String(dec.decodeBuffer(str));
		} catch (IOException io) {
			throw new RuntimeException(io.getMessage(), io.getCause());
		}
	}
	
	public static void main(String[] args) {
                String passString = "123456";
		String newpass = PasswordMD5Encryption.encodeString(passString);
		System.out.println(passString+" 加密后的字符串是 : " + newpass);
		String newpassAgin = PasswordMD5Encryption.decodeString(newpass);
		System.out.println(newpass+" 加密后再解密的字符串是 : " + newpassAgin);
	}
}

 

 

 

转载于:https://blog.51cto.com/ajiao13/1134208