1.md5存儲:只加密,不解密
insert into admin(passwd) values(md5('admin'));
結果:21232f297a57a5a743894a0e4a801fc3
java代碼:轉http://blog.sina.com.cn/s/blog_6b275753010161t3.html
MD5Util.java
package example.yue;
import java.security.MessageDigest;
public class MD5Util {
public final static String MD5(String s){
char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
try {
byte[] btInput = s.getBytes();
// 獲得MD5摘要算法的 MessageDigest 對象
MessageDigest mdInst = MessageDigest.getInstance("MD5");
// 使用指定的字節更新摘要
mdInst.update(btInput);
// 獲得密文
byte[] md = mdInst.digest();
// 把密文轉換成十六進制的字符串形式
int j = md.length;
char str[] = new char[j * 2];
int k = 0;
for (int i = 0; i < j; i++) {
byte byte0 = md[i];
str[k++] = hexDigits[byte0 >>> 4 & 0xf];
str[k++] = hexDigits[byte0 & 0xf];
}
return new String(str);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
test.jsp
<%@ page language="java" import="example.yue.MD5Util"%>
<%MD5Util md5=new MD5Util();
out.print(md5.MD5("admin"));
out.print("<br />");
out.print(MD5Util.MD5("admin"));%>
結果: