org.apache.hadoop.hive.ql.udf.generic.GenericUDFLower Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.hadoop.hive.ql.udf.generic;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.StringLower;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorConverter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorConverter.StringConverter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.typeinfo.BaseCharTypeInfo;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
/**
* UDFLower.
*
*/
@Description(name = "lower,lcase",
value = "_FUNC_(str) - Returns str with all characters changed to lowercase",
extended = "Example:\n"
+ " > SELECT _FUNC_('Facebook') FROM src LIMIT 1;\n" + " 'facebook'")
@VectorizedExpressions({StringLower.class})
public class GenericUDFLower extends GenericUDF {
private transient PrimitiveObjectInspector argumentOI;
private transient StringConverter stringConverter;
private transient PrimitiveCategory returnType = PrimitiveCategory.STRING;
private transient GenericUDFUtils.StringHelper returnHelper;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 1) {
throw new UDFArgumentLengthException(
"LOWER requires 1 argument, got " + arguments.length);
}
if (arguments[0].getCategory() != Category.PRIMITIVE) {
throw new UDFArgumentException(
"LOWER only takes primitive types, got " + arguments[0].getTypeName());
}
argumentOI = (PrimitiveObjectInspector) arguments[0];
stringConverter = new PrimitiveObjectInspectorConverter.StringConverter(argumentOI);
PrimitiveCategory inputType = argumentOI.getPrimitiveCategory();
ObjectInspector outputOI = null;
BaseCharTypeInfo typeInfo;
switch (inputType) {
case CHAR:
// return type should have same length as the input.
returnType = inputType;
typeInfo = TypeInfoFactory.getCharTypeInfo(
GenericUDFUtils.StringHelper.getFixedStringSizeForType(argumentOI));
outputOI = PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(typeInfo);
break;
case VARCHAR:
// return type should have same length as the input.
returnType = inputType;
typeInfo = TypeInfoFactory.getVarcharTypeInfo(
GenericUDFUtils.StringHelper.getFixedStringSizeForType(argumentOI));
outputOI = PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(typeInfo);
break;
default:
returnType = PrimitiveCategory.STRING;
outputOI = PrimitiveObjectInspectorFactory.writableStringObjectInspector;
break;
}
returnHelper = new GenericUDFUtils.StringHelper(returnType);
return outputOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
String val = null;
if (arguments[0] != null) {
val = (String) stringConverter.convert(arguments[0].get());
}
if (val == null) {
return null;
}
val = val.toLowerCase();
return returnHelper.setReturnValue(val);
}
@Override
public String getDisplayString(String[] children) {
return getStandardDisplayString("lower", children);
}
}