enable logging

enable logging

than the specified value.

https://github.com/apache/incubator-wayang/blob/d46f3c3f0fb963c2ee2640f00a106042fba55431/wayang-api/wayang-api-sql/src/main/java/org/apache/wayang/api/sql/sources/fs/CsvRowConverter.java#L146

```java

/*
* 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.wayang.api.sql.sources.fs;

import au.com.bytecode.opencsv.CSVParser;
import org.apache.calcite.avatica.util.DateTimeUtils;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.commons.lang3.time.FastDateFormat;

import java.io.IOException;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.ParseException;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

/**
* Based on Calcite's CSV enumerator.
* TODO: handle different variants
*
*/
public class CsvRowConverter {

private static final CSVParser parser;

private static final FastDateFormat TIME_FORMAT_DATE;
private static final FastDateFormat TIME_FORMAT_TIME;
private static final FastDateFormat TIME_FORMAT_TIMESTAMP;

static {
final TimeZone gmt = TimeZone.getTimeZone("GMT");
TIME_FORMAT_DATE = FastDateFormat.getInstance("yyyy-MM-dd", gmt);
TIME_FORMAT_TIME = FastDateFormat.getInstance("HH:mm:ss", gmt);
TIME_FORMAT_TIMESTAMP = FastDateFormat.getInstance("yyyy-MM-dd HH:mm:ss", gmt);

parser = new CSVParser();
}

public static Object convert(RelDataType fieldType, String string) {
if (fieldType == null || string == null) {
return string;
}
switch (fieldType.getSqlTypeName()) {
case BOOLEAN:
if (string.length() == 0) {
return null;
}
return Boolean.parseBoolean(string);
case TINYINT:
if (string.length() == 0) {
return null;
}
return Byte.parseByte(string);
case SMALLINT:
if (string.length() == 0) {
return null;
}
return Short.parseShort(string);
case INTEGER:
if (string.length() == 0) {
return null;
}
return Integer.parseInt(string);
case BIGINT:
if (string.length() == 0) {
return null;
}
return Long.parseLong(string);
case FLOAT:
if (string.length() == 0) {
return null;
}
return Float.parseFloat(string);
case DOUBLE:
if (string.length() == 0) {
return null;
}
return Double.parseDouble(string);
case DECIMAL:
if (string.length() == 0) {
return null;
}
return parseDecimal(fieldType.getPrecision(), fieldType.getScale(), string);
case DATE:
if (string.length() == 0) {
return null;
}
try {
Date date = TIME_FORMAT_DATE.parse(string);
return (int) (date.getTime() / DateTimeUtils.MILLIS_PER_DAY);
} catch (ParseException e) {
return null;
}
case TIME:
if (string.length() == 0) {
return null;
}
try {
Date date = TIME_FORMAT_TIME.parse(string);
return (int) date.getTime();
} catch (ParseException e) {
return null;
}
case TIMESTAMP:
if (string.length() == 0) {
return null;
}
try {
Date date = TIME_FORMAT_TIMESTAMP.parse(string);
return date.getTime();
} catch (ParseException e) {
return null;
}
case VARCHAR:
default:
return string;
}
}

private static BigDecimal parseDecimal(int precision, int scale, String string) {
BigDecimal result = new BigDecimal(string);
// If the parsed value has more fractional digits than the specified scale, round ties away
// from 0.
if (result.scale() > scale) {
//TODO: enable logging
/*LOGGER.warn(
"Decimal value {} exceeds declared scale ({}). Performing rounding to keep the "
+ "first {} fractional digits.",
result, scale, scale);*/
result = result.setScale(scale, RoundingMode.HALF_UP);
}
// Throws an exception if the parsed value has more digits to the left of the decimal point
// than the specified value.
if (result.precision() - result.scale() > precision - scale) {
throw new IllegalArgumentException(String
.format(Locale.ROOT, "Decimal value %s exceeds declared precision (%d) and scale (%d).",
result, precision, scale));
}
return result;
}

public static String[] parseLine(String s) throws IOException {
return parser.parseLine(s);
}
}

```

d2860c46967a7ef4c79ca64f47103c7265136dac

Open wayang-api/wayang-api-sql/src/main/java/org/apache/wayang/api/sql/sources/fs/CsvRowConverter.java and inspect parseDecimal, especially the commented LOGGER.warn block. Check how logging is configured elsewhere in the project, then verify that values exceeding the declared scale produce the intended warning while rounding still occurs.

Written by the indexing model from the issue text.