Java tutorial
/* * Hivemall: Hive scalable Machine Learning Library * * Copyright (C) 2015 Makoto YUI * * Licensed 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 hivemall.tools.text; import hivemall.utils.codec.Base91; import hivemall.utils.hadoop.HiveUtils; import hivemall.utils.io.FastByteArrayOutputStream; import java.io.IOException; import java.util.Arrays; import javax.annotation.Nonnull; import org.apache.hadoop.hive.ql.exec.Description; import org.apache.hadoop.hive.ql.exec.UDFArgumentException; import org.apache.hadoop.hive.ql.metadata.HiveException; import org.apache.hadoop.hive.ql.udf.UDFType; import org.apache.hadoop.hive.ql.udf.generic.GenericUDF; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory; import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector; import org.apache.hadoop.io.BytesWritable; import org.apache.hadoop.io.Text; @Description(name = "unbase91", value = "_FUNC_(string) - Convert a BASE91 string to a binary") @UDFType(deterministic = true, stateful = false) public final class Unbase91UDF extends GenericUDF { private StringObjectInspector stringOI; @Nonnull private transient FastByteArrayOutputStream outputBuf; @Nonnull private transient BytesWritable result; @Override public ObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException { if (argOIs.length != 1) { throw new UDFArgumentException("_FUNC_ takes exactly 1 argument"); } this.stringOI = HiveUtils.asStringOI(argOIs[0]); return PrimitiveObjectInspectorFactory.writableBinaryObjectInspector; } @Override public BytesWritable evaluate(DeferredObject[] arguments) throws HiveException { if (outputBuf == null) { this.outputBuf = new FastByteArrayOutputStream(4096); } else { outputBuf.reset(); } Object arg0 = arguments[0].get(); if (arg0 == null) { return null; } Text input = stringOI.getPrimitiveWritableObject(arg0); final byte[] inputBytes = input.getBytes(); final int len = input.getLength(); try { Base91.decode(inputBytes, 0, len, outputBuf); } catch (IOException e) { throw new HiveException(e); } if (result == null) { byte[] outputBytes = outputBuf.toByteArray(); this.result = new BytesWritable(outputBytes); } else { byte[] outputBytes = outputBuf.getInternalArray(); int outputSize = outputBuf.size(); result.set(outputBytes, 0, outputSize); } return result; } @Override public void close() throws IOException { this.outputBuf = null; this.result = null; } @Override public String getDisplayString(String[] children) { return "unbase91(" + Arrays.toString(children) + ')'; } }