[Java How To] #3 Creating MD5 Hashes Without a Plugin

*UPDATE: Servoy 4 appears to provide a built-in function for creating base-64-encoded, MD5 hashes. The function is located in "Utils" and as of RC1 is named "stringMD5HashBase64".

A PDF version of this post, which includes a code walkthru, is available here

Java How-To's are intended to provide real-world examples of how Java can be used to easily extend Servoy in useful ways. I will try to post a new one as often as possible.

Description

If you thought you needed a plugin to create MD5 hashes, think again. Because Servoy has such great support for Java, you can actually create MD5 hashes without using a plugin, by simply embedding some Java code directly within your Servoy method.

Java Classes Used

For more information about any of the Java classes used, click their corresponding link below.

• java.lang.Byte
  
• java.security.MessageDigest
  
• java.lang.Integer
  

Total Lines of Code

20 or so

The Servoy Code

var string_to_hash = 'Hello World!';

// Get an array of bytes from the input string
var in_array =  Array(string_to_hash.length);
var in_char;

for (var i = 0;  i < in_char =" string_to_hash.slice(i,i+1)" inbytearray =" new" i =" 0;" md =" Packages.java.security.MessageDigest.getInstance(" md5_bytearray =" md.digest(in_array);" md5_hash =" '';//empty" md5_array =" new" i =" 0;"> 2) {
 // Take right most 2 chars
 md5_array[i] = md5_array[i].substr(md5_array[i].length - 2, 2);
}

if ((md5_byteArray[i] >= 0 ) && (md5_byteArray[i] <= 15)) {   // Pre-pend a '0' since the hex to string fails to do so - typical to forget!   md5_array[i] = '0' + md5_array[i];  }    md5_hash += md5_array[i];//concatenate }   return md5_hash; 

In Summary

That's it! Creating MD5 hashes without a plugin. Please post any questions or comments you may have to the blog.

IMPORTANT: Please be advised that you should always backup your Servoy solution before implementing or attempting any of the techniques described in this blog. None of the techniques described are guaranteed to work in any way shape or form, or for any specific purpose. Use them entirely at your own risk.