/**
* 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;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CodingErrorAction;
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.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ConstantObjectInspector;
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.BinaryObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;
import org.apache.hadoop.io.Text;
@Description(name = "decode",
value = "_FUNC_(bin, str) - Decode the first argument using the second argument character set",
extended = "Possible options for the character set are 'US_ASCII', 'ISO-8859-1',\n" +
"'UTF-8', 'UTF-16BE', 'UTF-16LE', and 'UTF-16'. If either argument\n" +
"is null, the result will also be null")
public class GenericUDFDecode extends GenericUDF {
private transient CharsetDecoder decoder = null;
private transient BinaryObjectInspector bytesOI = null;
private transient StringObjectInspector charsetOI = null;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 2) {
throw new UDFArgumentLengthException("Encode() requires exactly two arguments");
}
if (arguments[0].getCategory() != Category.PRIMITIVE ||
((PrimitiveObjectInspector)arguments[0]).getPrimitiveCategory() != PrimitiveCategory.BINARY){
throw new UDFArgumentTypeException(0, "The first argument to Encode() must be a binary");
}
bytesOI = (BinaryObjectInspector) arguments[0];
if (arguments[1].getCategory() != Category.PRIMITIVE ||
((PrimitiveObjectInspector)arguments[1]).getPrimitiveCategory() != PrimitiveCategory.STRING){
throw new UDFArgumentTypeException(1, "The second argument to Encode() must be a string");
}
charsetOI = (StringObjectInspector) arguments[1];
// If the character set for encoding is constant, we can optimize that
StringObjectInspector charSetOI = (StringObjectInspector) arguments[1];
if (charSetOI instanceof ConstantObjectInspector){
String charSetName = ((Text) ((ConstantObjectInspector) charSetOI).getWritableConstantValue()).toString();
decoder = Charset.forName(charSetName).newDecoder().onMalformedInput(CodingErrorAction.REPORT).onUnmappableCharacter(CodingErrorAction.REPORT);
}
return (ObjectInspector) PrimitiveObjectInspectorFactory.javaStringObjectInspector;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
byte[] value = bytesOI.getPrimitiveJavaObject(arguments[0].get());
if (value == null) {
return null;
}
ByteBuffer wrappedBytes = ByteBuffer.wrap(value);
CharBuffer decoded;
if (decoder != null){
try {
decoded = decoder.decode(wrappedBytes);
} catch (CharacterCodingException e) {
throw new HiveException(e);
}
} else {
decoded = Charset.forName(charsetOI.getPrimitiveJavaObject(arguments[1].get())).decode(wrappedBytes);
}
return decoded.toString();
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == 2);
StringBuilder sb = new StringBuilder();
sb.append("encode(");
sb.append(children[0]).append(",");
sb.append(children[1]).append(")");
return sb.toString();
}
}