private List<NprDto> getUniqueAccountList(List<NprDto> nonUniqueAccountList) throws Exception {

    Map<Long,NprDto> uniqueAccountsMapList = new HashMap<Long,NprDto>();
    List<NprDto> uniqueAccountsList = null;

    if(nonUniqueAccountList != null && !nonUniqueAccountList.isEmpty()) {
        for(NprDto nprDto : nonUniqueAccountList) {
            uniqueAccountsMapList.put(Long.valueOf(nprDto.getAccountId()), nprDto);
        }
    }

    uniqueAccountsList = new ArrayList<NprDto>(uniqueAccountsMapList.values());

    return uniqueAccountsList;

}

class NprDto{
   Long accountId;
   .......

 @Override
 public boolean equals(Object obj) {
   NproDto other=(NproDto) obj;
   return this.accountId==other.accountId;
 }

 @Override
 public int hashCode() {
    return accountId.hashCode();
 }
}

private Set<NprDto> getUniqueAccountSet(){
    Map<Long,NprDto> uniqueAccountsMapList = new HashMap<Long,NprDto>();
    Set<NprDto> uniqueAccounts = new HashSet<NprDto>(uniqueAccountsMapList.values());
    return uniqueAccounts;

}

private List<NprDto> getUniqueAccountList(List<NprDto> nonUniqueAccountList) {
    return new ArrayList<NprDto>(new LinkedHashSet<NprDto>(nonUniqueAccountList));
}