GroupByResult

GroupByResult 表示分组聚合操作的结果。

类定义

    public  class GroupByResult implements java.io.Closeable
    {
        private SequenceIterator aggIterator;
        private SequenceIterator grpIterator;
         
        GroupByResult(long[] handles) 
        {
            aggIterator = new SequenceIterator(handles[0]);
            grpIterator = new SequenceIterator(handles[1]);
        }
         
        public SequenceIterator getAggIterator() 
        {
            return aggIterator;
        }
         
        public SequenceIterator getGroupIterator() 
        {
            return grpIterator;
        }
         
        public void close() 
        {
            if (grpIterator != null) 
            {
                close(grpIterator.handle);
                grpIterator = null;
                aggIterator = null;
            }
        }
    };

方法

GroupByResult

GroupByResult(long[] handles)：构造函数：返回一个 GroupByResult 实例

getAggIterator

public SequenceIterator getAggIterator()：返回每个组计算出的聚合结果的序列迭代器

getGroupIterator

public SequenceIterator getGroupIterator()：返回分组值的序列迭代器

close

public void close()：释放哈希表使用的内存