Java tutorial
/* * 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.beam.sdk.io.solr; import com.google.auto.service.AutoService; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Arrays; import java.util.List; import org.apache.beam.sdk.coders.AtomicCoder; import org.apache.beam.sdk.coders.Coder; import org.apache.beam.sdk.coders.CoderException; import org.apache.beam.sdk.coders.CoderProvider; import org.apache.beam.sdk.coders.CoderProviderRegistrar; import org.apache.beam.sdk.coders.CoderProviders; import org.apache.beam.sdk.util.VarInt; import org.apache.beam.sdk.values.TypeDescriptor; import org.apache.commons.compress.utils.BoundedInputStream; import org.apache.solr.common.SolrDocument; import org.apache.solr.common.SolrInputDocument; import org.apache.solr.common.util.JavaBinCodec; /** A {@link Coder} that encodes using {@link JavaBinCodec}. */ class JavaBinCodecCoder<T> extends AtomicCoder<T> { private final Class<T> clazz; private JavaBinCodecCoder(Class<T> clazz) { this.clazz = clazz; } public static <T> JavaBinCodecCoder<T> of(Class<T> clazz) { return new JavaBinCodecCoder<>(clazz); } @Override public void encode(T value, OutputStream outStream) throws IOException { if (value == null) { throw new CoderException("cannot encode a null SolrDocument"); } ByteArrayOutputStream baos = new ByteArrayOutputStream(); JavaBinCodec codec = new JavaBinCodec(); codec.marshal(value, baos); byte[] bytes = baos.toByteArray(); VarInt.encode(bytes.length, outStream); outStream.write(bytes); } @Override public T decode(InputStream inStream) throws IOException { DataInputStream in = new DataInputStream(inStream); int len = VarInt.decodeInt(in); if (len < 0) { throw new CoderException("Invalid encoded SolrDocument length: " + len); } JavaBinCodec codec = new JavaBinCodec(); return (T) codec.unmarshal(new BoundedInputStream(in, len)); } @Override public TypeDescriptor<T> getEncodedTypeDescriptor() { return TypeDescriptor.of(clazz); } @AutoService(CoderProviderRegistrar.class) public static class Provider implements CoderProviderRegistrar { @Override public List<CoderProvider> getCoderProviders() { return Arrays.asList( CoderProviders.forCoder(TypeDescriptor.of(SolrDocument.class), JavaBinCodecCoder.of(SolrDocument.class)), CoderProviders.forCoder(TypeDescriptor.of(SolrInputDocument.class), JavaBinCodecCoder.of(SolrInputDocument.class))); } } }