Re: HashMap toString, what about the other way?

On Tue, 13 Nov 2007 17:21:33 -0800, Bas <basschulte@gmail.com> wrote,
quoted or indirectly quoted someone who said :


// Build a HashMap, convert to String, and recreate the HashMap.
import java.util.HashMap;
import java.util.regex.Pattern;
public class HashString
   {

   /**
    * test harness
    *
    * @param args not used
    */
   public static void main ( String[] args )
      {

      HashMap<String,String >h1 = new HashMap<String,String>( 11 );
      h1.put ("apple","red");
      h1.put ("peach","yellow");
      h1.put ("mango","orange");
      String everything = h1.toString();
      System.out.println( everything );
      // prints {apple=red, mango=orange, peach=yellow}

      // take the answer apart
      Pattern p = Pattern.compile("[\\{\\}\\=\\, ]++");
      String[] split = p.split( everything );
      for ( String s: split )
         {
         System.out.println( '\"' + s + '\"' );
         }
      // prints:
      // ""
      // "apple"
      // "red"
      // "mango"
      // "orange"
      // "peach"
      // "yellow"

      // put it back together again.
      HashMap<String,String >h2 = new HashMap<String,String>( 11 );
      for ( int i=1; i< split.length; i+=2 )
         {
         h2.put( split[i], split[i+1] );
         }
      System.out.println( h2.toString() );
      // prints: {apple=red, peach=yellow, mango=orange}
      }
   }

Also see http://mindprod.com/jgloss/serialization.html
--
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com