Java tutorial
/** * Copyright (C) cedarsoft GmbH. * * Licensed under the GNU General Public License version 3 (the "License") * with Classpath Exception; you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.cedarsoft.org/gpl3ce * (GPL 3 with Classpath Exception) * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 3 only, as * published by the Free Software Foundation. cedarsoft GmbH designates this * particular file as subject to the "Classpath" exception as provided * by cedarsoft GmbH in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 3 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 3 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact cedarsoft GmbH, 72810 Gomaringen, Germany, * or visit www.cedarsoft.com if you need additional information or * have any questions. */ package com.cedarsoft.couchdb.io; import com.cedarsoft.couchdb.core.CouchDoc; import com.cedarsoft.couchdb.core.DocId; import com.cedarsoft.couchdb.core.Row; import com.cedarsoft.serialization.jackson.InvalidTypeException; import com.cedarsoft.serialization.jackson.JacksonParserWrapper; import com.cedarsoft.serialization.jackson.JacksonSerializer; import com.cedarsoft.serialization.jackson.JacksonSupport; import com.fasterxml.jackson.core.JsonEncoding; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonToken; import javax.annotation.Nonnull; import javax.annotation.Nullable; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; /** * */ public class RowSerializer { public static final String PROPERTY_ID = "id"; public static final String PROPERTY_KEY = "key"; public static final String PROPERTY_VALUE = "value"; @Nonnull private final CouchDocSerializer couchDocSerializer; @Deprecated public RowSerializer() { this(new CouchDocSerializer()); } public RowSerializer(@Nonnull CouchDocSerializer couchDocSerializer) { this.couchDocSerializer = couchDocSerializer; } public <K, V> void serialize(@Nonnull Row<K, V, ?> row, @Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nonnull OutputStream out) throws IOException { serialize(row, keySerializer, valueSerializer, null, out); } public <K, V> void serialize(@Nonnull Row<K, V, ?> row, @Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nonnull JsonGenerator generator) throws IOException { serialize(row, keySerializer, valueSerializer, null, generator); } public <K, V, D> void serialize(@Nonnull Row<K, V, D> row, @Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nullable JacksonSerializer<? super D> documentSerializer, @Nonnull OutputStream out) throws IOException { JsonFactory jsonFactory = JacksonSupport.getJsonFactory(); JsonGenerator generator = jsonFactory.createJsonGenerator(out, JsonEncoding.UTF8); serialize(row, keySerializer, valueSerializer, documentSerializer, generator); generator.close(); } public <K, V, D> void serialize(@Nonnull Row<K, V, D> row, @Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nullable JacksonSerializer<? super D> documentSerializer, @Nonnull JsonGenerator generator) throws IOException { generator.writeStartObject(); @Nullable DocId id = row.getId(); if (id != null) { generator.writeStringField(PROPERTY_ID, id.asString()); } //The key generator.writeFieldName(PROPERTY_KEY); keySerializer.serialize(row.getKey(), generator); //The Value generator.writeFieldName(PROPERTY_VALUE); V value = row.getValue(); if (value == null) { generator.writeNull(); } else { valueSerializer.serialize(value, generator); } //The doc CouchDoc<? extends D> doc = row.getDoc(); if (doc != null) { if (documentSerializer == null) { throw new NullPointerException("documentSerializer must not be null when serializing a doc"); } generator.writeFieldName("doc"); couchDocSerializer.serialize(doc, documentSerializer, generator); } generator.writeEndObject(); } @Nonnull public <K, V> Row<K, V, Void> deserialize(@Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nonnull InputStream in) throws IOException, InvalidTypeException { return deserialize(keySerializer, valueSerializer, null, in); } @Nonnull public <K, V, D> Row<K, V, D> deserialize(@Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nullable JacksonSerializer<? extends D> documentSerializer, @Nonnull InputStream in) throws IOException, InvalidTypeException { JsonFactory jsonFactory = JacksonSupport.getJsonFactory(); JsonParser parser = jsonFactory.createJsonParser(in); JacksonParserWrapper parserWrapper = new JacksonParserWrapper(parser); parserWrapper.nextToken(JsonToken.START_OBJECT); return deserialize(keySerializer, valueSerializer, documentSerializer, parser); } @Nonnull public <K, V> Row<K, V, Void> deserialize(@Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nonnull JsonParser parser) throws IOException, InvalidTypeException { return deserialize(keySerializer, valueSerializer, null, parser); } @Nonnull public <K, V, D> Row<K, V, D> deserialize(@Nonnull JacksonSerializer<? super K> keySerializer, @Nonnull JacksonSerializer<? super V> valueSerializer, @Nullable JacksonSerializer<? extends D> documentSerializer, @Nonnull JsonParser parser) throws IOException, InvalidTypeException { JacksonParserWrapper wrapper = new JacksonParserWrapper(parser); wrapper.nextToken(JsonToken.FIELD_NAME); String fieldName = wrapper.getCurrentName(); //The id @Nullable final DocId id; if (fieldName.equals(PROPERTY_ID)) { wrapper.nextValue(); id = new DocId(wrapper.getText()); wrapper.nextField(PROPERTY_KEY); } else { id = null; } //The key K key = (K) keySerializer.deserialize(parser); //The value wrapper.nextField(PROPERTY_VALUE); @Nullable V value = (V) valueSerializer.deserialize(parser); //The doc - if available @Nullable CouchDoc<? extends D> doc; JsonToken nextToken = wrapper.nextToken(); if (nextToken == JsonToken.FIELD_NAME) { if (documentSerializer == null) { throw new NullPointerException("No document serializer found"); } doc = couchDocSerializer.deserialize(documentSerializer, new JacksonParserWrapper(parser)); wrapper.closeObject(); } else { doc = null; } wrapper.verifyCurrentToken(JsonToken.END_OBJECT); return new Row<>(id, key, value, doc); } }