Android Beginner Tutorial: MD5 Encryption Tool class for files and strings

Reprint please indicate the source: http://blog.csdn.net/qq_32059827/article/details/52200008 Click to open the link

I have previously written a blog post that is MD5 encrypted for strings. Today, it is improved by adding MD5 encryption for a file, and getting the encrypted value. And two functions are packaged into a tool class, if there is a need for this algorithm, can be used directly.

Directly on the algorithm encapsulation of the tool class code:

Package Com.itydl.utils;import Java.io.file;import Java.io.fileinputstream;import java.io.FileNotFoundException; Import Java.io.ioexception;import java.security.messagedigest;import java.security.nosuchalgorithmexception;/** *  MD5 encryption for strings, and tool classes involving MD5 operations * @author Lenovo * */public class Md5utils {/** * Returns the MD5 value of the file * @param path * Paths of files to encrypt * @return * The MD5 value of the file */public the static string getFileMD5 (string path) {StringBuilder sb = new StringBuilder (); try {FileInputStream fis = new FileInputStream (path);//Get MD5 dongle messagedigest MD = messagedigest.getinstance ("MD5");//Read file byte[] bytes = new byte[10240];//One read write 10kint len = 0;while (len = fis.read (bytes))!=-1) {//Read data from original destination//write data to MD cipher, analogy Fos.write ( Bytes, 0, Len); md.update (bytes, 0, len);} Read the entire file data and write to the MD cipher byte[] Digest = Md.digest ();//Complete the encryption, get the MD5 value, but the byte type. I'm going to do the final conversion. for (byte b:digest) {//traversal bytes, stitching each byte together//convert each byte to 16 binary int d = b & 0xff;//Keep only the last two digits of string herstring = Integer.toh Exstring (d);//convert int type data to 16 binary string representation//If there is only one, then 0 is in front. Let it also be two-bit if (herString.Length () ==1) {//bytes high 4 bits 0herString = "0" +herstring;//stitching string, two bits representing}sb.append (herstring);}} catch (FileNotFoundException e) {//TODO auto-generated catch Blocke.printstacktrace ();} catch ( NoSuchAlgorithmException e) {//Todo auto-generated catch Blocke.printstacktrace ();} catch (IOException e) {//Todo auto-g Enerated catch Blocke.printstacktrace ();} return sb.tostring ();} /** * MD5 encryption of strings passed in * @param str * String to be encrypted * @return * string Md5 encrypted result */public static string MD5 (String str) {Stringbuilde R sb = new StringBuilder ();//String container try {//Get MD5 dongle. public static MessageDigest getinstance (string algorithm) returns the implementation of the specified digest algorithm. The MessageDigest object. MessageDigest MD = messagedigest.getinstance ("MD5"); byte[] bytes = Str.getbytes ();//Convert the string to be encrypted into a byte array byte[] Digest = Md.digest (bytes);//Use the specified "byte array" to make a final update of the digest, and then complete the summary calculation. That is, complete the MD5 encryption for (byte b:digest) {//convert each byte to 16 binary int d = b & 0xff;//only retain the latter two digits of string herstring = Integer.tohexstring (d);// int type data to 16 binary string representation//If there is only one bit, then 0 is in front. Let it be also two-bit if (Herstring.length () ==1) {//bytes high 4 bits 0heRString = "0" +herstring;//stitching string, two bits to represent}sb.append (herstring);}} catch (NoSuchAlgorithmException e) {//TODO auto-generated catch Blocke.printstacktrace ();} return sb.tostring ();}}

Android Beginner Tutorial: MD5 Encryption Tool class for files and strings