java - Java ArrayList 日期变量排序？

Question

我希望我的列表将根据Date变量进行排序，所以我必须编写这个逻辑

public  static void main(String a[]){
        AuditLogComponent comp = new AuditLogComponent();
        List<TableRecord> records = new ArrayList<TableRecord>();
        LogFolderRecord log = new LogFolderRecord();
        Date date = new Date();
        Timestamp fromTS1 = new Timestamp(date.getTime());
        log.setStampDate(fromTS1);
        records.add(log);
        Date date1 = new Date();
        Timestamp fromTS2 = new Timestamp(date1.getTime());
        LogFolderRecord log1 = new LogFolderRecord();
        log1.setStampDate(fromTS2);
        records.add(log1);
        records.add(new LogPeopleRecord());

        comp.columnsList(records);
    }

以及我如何调用 List 的 Sort 方法

public void columnsList(List<TableRecord> records){

          Collections.sort(records, new StampDateComparator());
        for(TableRecord record : records){
            Table table = record.getTable();
            Field[] fields = table.fields();
            for(Field field : fields){
                field.getName();
                record.getValue(field);

            }
        }

    }

我的 Comparator 类是

public class StampDateComparator implements Comparator<Object> {

    @Override
    public int compare(Object object1, Object object2) {

        try {
            Method method = object1.getClass().getDeclaredMethod("getStampDate");
            Date value = (Date) method.invoke(object1);

            Method method1 = object1.getClass().getDeclaredMethod("getStampDate");
            Date value1 = (Date) method.invoke(object2);

            if(value != null && value1 != null )
            return  value.compareTo(value1);;
        } catch (SecurityException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }   catch (NoSuchMethodException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }  
        return 0;

    }

但它不会抛出异常

java.lang.IllegalArgumentException: object is not an instance of declaring class
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.csdcsystems.amanda.comp.macro.StampDateComparator.compare(StampDateComparator.java:22)
    at java.util.TimSort.countRunAndMakeAscending(Unknown Source)
    at java.util.TimSort.sort(Unknown Source)

根据日期进行排序的确切方法是什么？

score 2 · Accepted Answer

你的Comparator班级应该看起来像

public class StampDateComparator implements Comparator<TableRecord> {

    @Override
    public int compare(TableRecord record1, TableRecord record2) {
        return record1.getStampDate().compareTo(record2.getStampDate());
    }
}

编辑：即使TableRecord是一个接口，您仍然可以在您的中使用它，您的Compartor所有实现都TableRecord应该getStampDate正确实现该方法。

score 0 · Accepted Answer

在Comparator课堂上，首先你需要Timestamp从TableRecord课堂上获得。Timestamp有它compareTo的排序方法。设计你的StampDateComparator类，如：

public class StampDateComparator implements Comparator<TableRecord> {

    @Override
    public int compare(TableRecord record1, TableRecord record2) {
        Timestamp timestamp1=record1.getStampDate();        
        Timestamp timestamp2=record2.getStampDate();
        return timestamp1.compareTo(timestamp2);
    }
}

score 0 · Accepted Answer

getDeclaredMethod和的方法签名invoke是错误的：

Method method = object1.getClass().getDeclaredMethod("getStampDate", null);
Date value = (Date) method.invoke(object1, null);

Method method1 = object2.getClass().getDeclaredMethod("getStampDate", null);
Date value1 = (Date) method.invoke(object2, null);

他们需要方法的参数。请参阅 JavaDoc：

java - Java ArrayList 日期变量排序？

3 回答 3

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