org.apache.hadoop.hive.ql.udf.generic.GenericUDFDateFormat Maven / Gradle / Ivy
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/**
* 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.hadoop.hive.ql.udf.generic;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.DATE_GROUP;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.STRING_GROUP;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ConstantObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.Text;
/**
* GenericUDFDateFormat.
*
* converts a date/timestamp/string to a value of string in the format specified
* by the java date format
*
*/
@Description(name = "date_format", value = "_FUNC_(date/timestamp/string, fmt) - converts a date/timestamp/string "
+ "to a value of string in the format specified by the date format fmt.",
extended = "Supported formats are SimpleDateFormat formats - "
+ "https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html. "
+ "Second argument fmt should be constant.\n"
+ "Example: > SELECT _FUNC_('2015-04-08', 'y');\n '2015'")
public class GenericUDFDateFormat extends GenericUDF {
private transient Converter[] tsConverters = new Converter[2];
private transient PrimitiveCategory[] tsInputTypes = new PrimitiveCategory[2];
private transient Converter[] dtConverters = new Converter[2];
private transient PrimitiveCategory[] dtInputTypes = new PrimitiveCategory[2];
private final Text output = new Text();
private transient SimpleDateFormat formatter;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
checkArgsSize(arguments, 2, 2);
checkArgPrimitive(arguments, 0);
checkArgPrimitive(arguments, 1);
// the function should support both short date and full timestamp format
// time part of the timestamp should not be skipped
checkArgGroups(arguments, 0, tsInputTypes, STRING_GROUP, DATE_GROUP);
checkArgGroups(arguments, 0, dtInputTypes, STRING_GROUP, DATE_GROUP);
checkArgGroups(arguments, 1, tsInputTypes, STRING_GROUP);
obtainTimestampConverter(arguments, 0, tsInputTypes, tsConverters);
obtainDateConverter(arguments, 0, dtInputTypes, dtConverters);
if (arguments[1] instanceof ConstantObjectInspector) {
String fmtStr = getConstantStringValue(arguments, 1);
if (fmtStr != null) {
try {
formatter = new SimpleDateFormat(fmtStr);
} catch (IllegalArgumentException e) {
// ignore
}
}
} else {
throw new UDFArgumentTypeException(1, getFuncName() + " only takes constant as "
+ getArgOrder(1) + " argument");
}
ObjectInspector outputOI = PrimitiveObjectInspectorFactory.writableStringObjectInspector;
return outputOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
if (formatter == null) {
return null;
}
// the function should support both short date and full timestamp format
// time part of the timestamp should not be skipped
Date date = getTimestampValue(arguments, 0, tsConverters);
if (date == null) {
date = getDateValue(arguments, 0, dtInputTypes, dtConverters);
if (date == null) {
return null;
}
}
String res = formatter.format(date);
if (res == null) {
return null;
}
output.set(res);
return output;
}
@Override
public String getDisplayString(String[] children) {
return getStandardDisplayString(getFuncName(), children);
}
@Override
protected String getFuncName() {
return "date_format";
}
}