google app engine - HashSet turning into TreeSet when unit testing JDO GAE/J app in maven -


i have java app gae uses maven (the net.kindleit version) following classes:

public class c1 {      ...     @persistent(mappedby = "c1")     @element(dependent = "true")     private set<c2> c2s = new hashset<c2>();      public set<c2> getc2s() {         return this.c2s;     }     ''' }  public class c2 {      private c1 c1;      ...     more properties, getters , setters     ...  } 

in 1 of tests, executing following:

c2 myc2 = new c2(myc1); myc1.getc2s().add(myc2); 

the unit test works running inside eclipse, , code works in production app, when run unit tests under maven, test fails following:

java.lang.classcastexception:      com.me.model.c2 cannot cast java.lang.comparable     @ java.util.treemap.compare(treemap.java:1188)     @ java.util.treemap.put(treemap.java:531)     @ java.util.treeset.add(treeset.java:255)     @ com.me.service.c2serviceimpl.createc2(c2serviceimpl.java:319) 

i understand exception, c2 not implement comparable, , required insert things treeset, question is, why returning set backed treeset, , not hashset.


Comments

Popular posts from this blog

linux - Does gcc have any options to add version info in ELF binary file? -

android - send complex objects as post php java -

charts - What graph/dashboard product is facebook using in Dashboard: PUE & WUE -