/** * 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 kafka.serializer import kafka.utils.VerifiableProperties /** * A decoder is a method of turning byte arrays into objects. * An implementation is required to provide a constructor that * takes a VerifiableProperties instance. */ trait Decoder[T] { def fromBytes(bytes: Array[Byte]): T } /** * The default implementation does nothing, just returns the same byte array it takes in. */ class DefaultDecoder(props: VerifiableProperties = null) extends Decoder[Array[Byte]] { def fromBytes(bytes: Array[Byte]): Array[Byte] = bytes } /** * The string encoder translates strings into bytes. It uses UTF8 by default but takes * an optional property serializer.encoding to control this. */ class StringDecoder(props: VerifiableProperties = null) extends Decoder[String] { val encoding = if(props == null) "UTF8" else props.getString("serializer.encoding", "UTF8") def fromBytes(bytes: Array[Byte]): String = { new String(bytes, encoding) } }