Creation of custom comparator for map in groovy -

i have class in groovy

class whsdbfile {     string name     string path     string svnurl     string lastrevision     string lastmessage     string lastauthor } 

and map object

def installfiles = [:] 

that filled in loop by

whsdbfile dbfile = new whsdbfile() installfiles[svndiffstatus.getpath()] = dbfile 

now try sort custom comparator

        comparator<whsdbfile> whsdbfilecomparator = new comparator<whsdbfile>() {             @override             int compare(whsdbfile o1, whsdbfile o2) {                 if (filenameutils.getbasename(o1.name) > filenameutils.getbasename(o2.name)) {                     return 1                 } else if (filenameutils.getbasename(o1.name) > filenameutils.getbasename(o2.name)) {                     return -1                 }                 return 0             }         }         installfiles.sort(whsdbfilecomparator); 

but error java.lang.string cannot cast whsdbfile

any idea how fix this? need use custom comparator, cause more complex in future.

p.s. full source of sample gradle task (description of whsdbfile class above):

    project.task('sample') << {         def installfiles = [:]         whsdbfile dbfile = new whsdbfile()         installfiles['sample_path'] = dbfile         comparator<whsdbfile> whsdbfilecomparator = new comparator<whsdbfile>() {             @override             int compare(whsdbfile o1, whsdbfile o2) {                 if (o1.name > o2.name) {                     return 1                 } else if (o1.name > o2.name) {                     return -1                 }                 return 0             }         }         installfiles.sort(whsdbfilecomparator);     } 

you can try sort entryset() :

def sortedentries = installfiles.entryset().sort { entry1, entry2 ->    entry1.value <=> entry2.value  } 

you have collection of map.entry invocation. in order have map, can collectentries() result :

def sortedmap = installfiles.entryset().sort { entry1, entry2 ->        ...  }.collectentries()