Traversing map objects in java is very violent. You can get whatever you want.

Map<String,MateMatrix> mate=cahe.getAllMateMatrixs();

Set<Map.Entry<String,MateMatrix>> set = mate.entrySet();
 
for(Iterator<Map.Entry<String, MateMatrix>> it = set.iterator(); it.hasNext();){
Map.Entry<String, MateMatrix> entry = (Map.Entry<String, MateMatrix>) it.next();
           System.out.println(entry.getKey() + "--->" + entry.getValue().getDescription());
}