MD5工具类

转载地址：http://www.oschina.net/code/snippet_1031745_36882

md5的作用 就是检验文件有没有被别人修改类似的。主要用于验证信息。

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import java.security.MessageDigest; public class Md5 { Log log; public static String getMd5(String s) { char hexDigits[] = { '0' , '1' , '2' , '3' , '4' , '5' , '6' , '7' , '8' , '9' , 'a' , 'b' , 'c' , 'd' , 'e' , 'f' }; try { byte [] strTemp = s.getBytes(); MessageDigest mdTemp = MessageDigest.getInstance( "md5" ); mdTemp.update(strTemp); byte [] md = mdTemp.digest(); 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) { return null ; } } /** * 标准MD5加密 * * @param inStr * @return * @throws Exception */ public static String toMD5(String inStr) { StringBuffer sb = new StringBuffer(); try { MessageDigest md = MessageDigest.getInstance( "MD5" ); md.update(inStr.getBytes()); byte b[] = md.digest(); int i; for ( int offset = 0 ; offset < b.length; offset++) { i = b[offset]; if (i < 0 ) i += 256 ; if (i < 16 ) sb.append( "0" ); sb.append(Integer.toHexString(i)); } } catch (Exception e) { return null ; // e.printStackTrace(); } return sb.toString().toUpperCase(); } public static void main(String[] args) throws Exception { System.out.println(toMD5( "MATICSOFT" ).toUpperCase()); } }