Carsar加密算法在java中是最简单的加密算法，那么你知道要如何实现吗？下面我们就去看看JAVA如何实现caesar凯撒加密算法的内容。

public class Caesar {

public static final String SOURCE = "abcdefghijklmnopqrstuvwxyz";

public static final int LEN = SOURCE.length();

/**

* @param args

*/

public static void main(String[] args) {

String result = caesarEncryption("newyork");

System.out.println("encryption result:" + result);

System.out.println("decryption result:" + caesarDecryption(result));

}

//Encryption

public static String caesarEncryption(String s) {

StringBuilder sb = new StringBuilder();

if (s == null || s.length()

System.out.println("you Input nothing.");

return null;

}

if (!isAlp(s)) {

System.out.println("input ABC... only");

return null;

}

s = s.toLowerCase();

int len = s.length();

for (int j = 0; j

char c = s.charAt(j);

int a = SOURCE.indexOf(c);

if (a == LEN -1) a = -1;

if (a == LEN -2) a = -2;

if (a == LEN - 3) a = -3;

sb.append(SOURCE.charAt(a + 3));

}

return sb.toString();

}

//Decryption

public static String caesarDecryption(String s) {

StringBuilder sb = new StringBuilder();

if (s == null || s.length()

System.out.println("you Input nothing.");

return null;

}

if (!isAlp(s)) {

System.out.println("input ABC... only");

return null;

}

s = s.toLowerCase();

for (int i = 0; i

char c = s.charAt(i);

int a = SOURCE.indexOf(c);

if (a == 2) a = LEN + 2;

if (a == 1) a = LEN + 1;

if (a == 0) a = LEN;

sb.append(SOURCE.charAt(a - 3));

}

return sb.toString();

}

public static boolean isAlp(String s) {

String p = "^[A-Za-z]+$";

Pattern pattern = Pattern.compile(p);

Matcher matcher = pattern.matcher(s);

if (matcher.find()) {

return true;

}

return false;

}

}

以上内容就是小编介绍JAVA如何实现caesar凯撒加密算法的方法，是不是效果还不错呢，只要我们开动脑筋，就可以实现很多效果哦！