Java ArrayList 基于动态对象字段进行排序？

Question

我遇到一个问题，代码如下

public void columnsList(List<TableRecord> records){

    for(TableRecord record : records){
        Table table = record.getTable();
        //Do sort here on stampDate
        Field[] fields = table.fields();
        for(Field field : fields){
            field.getName();
            record.getValue(field);

        }
    }

}

和records对象包含不同类类型的对象

List<TableRecord> records = new List<TableRecord>();
records.add(new AddressRecord());
records.add(new CityRecord());
records.add(new UserRecord());

现在我需要如何通过每个类中的 stampDate 变量对它们进行排序，当列表中有不同的类时我们该怎么做

Answer 1

如果上面的代码正确，则意味着 AddressRecord、CityRecord 和 UserRecord 都扩展了 TableRecord:

class AddressRecord extends TableRecord {
    // other fields and methods here
}
class CityRecord extends TableRecord {
    // other fields and methods here
}
class UserRecord extends TableRecord {
    // other fields and methods here
}

您只需为此类编写一个Comparator。它应该看起来像这样:

class TableRecord {
    private Date timeStamp;

    public Date getTimeStamp() {
        return timeStamp;
    }
// other fields and methods here
}

class RecordStampDateComparator implements Comparator<TableRecord>{

    public int compare(TableRecord tr1, TableRecord tr2) {
        Date tr1Date = tr1.getTimeStamp();
        Date tr2Date = tr2.getTimeStamp();   
        return tr1Date.compareTo(tr2Date);
    }
}