shahriyar-novruzov commented on code in PR #1378: URL: https://github.com/apache/arrow-java/pull/1378#discussion_r4346257971
########## flight/flight-sql-jdbc-core/src/main/java/org/apache/arrow/driver/jdbc/converter/impl/DecimalParameterCoercer.java: ########## @@ -0,0 +1,59 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.arrow.driver.jdbc.converter.impl; + +import java.math.BigDecimal; +import java.math.RoundingMode; +import org.apache.calcite.avatica.remote.TypedValue; + +/** + * Widens Avatica {@link TypedValue}s bound to DECIMAL parameters to {@link BigDecimal}, so calls + * like {@code setDouble} against an Arrow {@code Decimal} parameter bind instead of throwing. + */ +final class DecimalParameterCoercer { + + private DecimalParameterCoercer() {} + + /** + * Returns the {@link BigDecimal} value of a {@link TypedValue} bound to a DECIMAL parameter, + * scaled to what the target vector stores. + * + * <p>A value is scaled rather than rejected on a mismatch: the client sent the number it had, and + * the column's scale is what it has to fit. Rounding is HALF_UP, as {@code setBigDecimal} does. + */ + static BigDecimal toBigDecimal(TypedValue typedValue, int scale) { + return widen(typedValue).setScale(scale, RoundingMode.HALF_UP); + } + + private static BigDecimal widen(TypedValue typedValue) { + final Object local = typedValue.toLocal(); + if (local instanceof BigDecimal) { + return (BigDecimal) local; + } + if (local instanceof Double || local instanceof Float) { + // valueOf, not new BigDecimal(double): the constructor keeps the binary expansion, so 0.1 + // arrives as 0.1000000000000000055511151231257827. + return BigDecimal.valueOf(((Number) local).doubleValue()); + } + if (local instanceof Number) { + return BigDecimal.valueOf(((Number) local).longValue()); + } Review Comment: This one can't happen — Avatica has no rep for BigInteger (ColumnMetaData.Rep.VALUE_MAP.get(BigInteger.class) is null), so toLocal() returns it as a BigDecimal and the first branch takes it. The longValue() branch is only reached by the integral wrappers, where nothing is lost. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
