使用Java 8 Lambda表达式查找注释列表是否具有不同的货币

Question

我有一个笔记列表，每个笔记都有特定的货币。如果所有票据都具有相同的货币，我想要退货。如果其中任何一个音符具有不同的货币，则抛出异常。如何使用Java 8 lambda表达式实现它？

    public class Money {
        private List<NoteTO> notes;

        public List<NoteTO> getNotes() {
            return notes;
        }

        public void setNotes(List<NoteTO> notes) {
            this.notes = notes;
        }
    }

    public class NoteTO {
        private Long noteId;
        private String currency;

        public Long getNoteId() {
            return noteId;
        }

        public void setNoteId(Long noteId) {
            this.noteId = noteId;
        }

        public String getCurrency() {
            return currency;
        }

        public void setCurrency(String currency) {
            this.currency = currency;
        }
    }

我通过以下方式实现了这一目标。但是，想要使用Lambda表达式做同样的事情。

    public void testMethod(){
        String currencyResponse = null;
        for(NoteTO note : notes){
            currencyResponse = checkCurrency(currencyResponse, note);
        }

        System.out.println("Currency : "+currencyResponse);
    }

    public String checkCurrency(String currencyResponse, NoteTO note) throws Exception {
        String currency = note.getCurrency();

        if(currencyResponse == null){
            return currency;
        } else if(!currencyResponse.equals(currency)){
            throw new Exception();
        }

        return currencyResponse;
    }