Every now and then I have to save a HashMap to a database or something and the most sensible way is to use the toString() method which gives a comma separated, equals delimited name value pair string, e.g. {name=bob,address=somewhere,phone=00-353-01-9875666}. This is useful for logging also (or audit trails). The problem arises when you want to read that string to a HashMap again. There is no native function to accomplish this.
I have outlined a simple method below which will accomplish this.
/**
* Converts a HashMap.toString() back to a HashMap
* @param text
* @return HashMap<String, String>
*/
protected HashMap<String, String> convertToStringToHashMap(String text){
HashMap<String, String> data = new HashMap<String,String>();
Pattern p = Pattern.compile("[\\{\\}\\=\\, ]++");
String[] split = p.split(text);
for ( int i=1; i< split.length; i+=2 ){
data.put( split[i], split[i+1] );
}
return data;
}
Essentially we take the string as a parameter and using the pattern we split the string into name value pairs, with the name as split[i] and the value as split[i+1]. We then use the HashMap.put() to add the pair back into the HashMap. The whole logic of this resides in the Pattern which is a simple regular expression, that shows to split by the '=' in side '{}'.
I hope you have found this useful. If you have any questions please leave a comment or email support[@]tomred.net
