Java 类org.apache.lucene.search.SortedNumericSortField 实例源码

/**
 * Sort the results of a numeric range query if the query in this context
 * is a {@link NumericRangeQuery}, see {@link #numericRange(String, Number, Number)},
 * Otherwise an {@link IllegalStateException} will be thrown.
 *
 * @param key the key to sort on.
 * @param reversed if the sort order should be reversed or not. {@code true}
 * for lowest first (ascending), {@code false} for highest first (descending)
 * @return a QueryContext with sorting by numeric value.
 */
public QueryContext sortNumeric( String key, boolean reversed )
{
    if ( !( queryOrQueryObject instanceof NumericRangeQuery ) )
    {
        throw new IllegalStateException( "Not a numeric range query" );
    }

    Number number = ((NumericRangeQuery)queryOrQueryObject).getMin();
    number = number != null ? number : ((NumericRangeQuery)queryOrQueryObject).getMax();
    SortField.Type fieldType = SortField.Type.INT;
    if ( number instanceof Long )
    {
        fieldType = SortField.Type.LONG;
    }
    else if ( number instanceof Float )
    {
        fieldType = SortField.Type.FLOAT;
    }
    else if ( number instanceof Double )
    {
        fieldType = SortField.Type.DOUBLE;
    }
    sort( new Sort( new SortedNumericSortField( key, fieldType, reversed ) ) );
    return this;
}

private static SortField getSortField(Pager pager) {
    if (DOC_ID_FIELD_NAME.equals(pager.getSortby())) {
        return new SortedNumericSortField(DOC_ID_FIELD_NAME, LONG, pager.isDesc());
    } else {
        return new SortField(pager.getSortby(), STRING, pager.isDesc());
    }
}

private QueryContext sort( QueryContext query, boolean reversed )
{
    return query.sort( new Sort( new SortedNumericSortField( FIELD, SortField.Type.LONG, reversed ) ) );
}