001/**
002 * Copyright (C) 2006-2021 Talend Inc. - www.talend.com
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.talend.sdk.component.api.service.record;
017
018import java.util.function.BiConsumer;
019import java.util.function.BiFunction;
020import java.util.stream.Collector;
021
022import org.talend.sdk.component.api.record.Record;
023import org.talend.sdk.component.api.record.Schema;
024
025/**
026 * Helping class to build records.
027 */
028public interface RecordService {
029
030    /**
031     * Simple mapper of record to pojo.
032     *
033     * @param data record to map to pojo.
034     * @param expected : class expected.
035     * @param <T> the pojo type (optional).
036     * @return a pojo representing the data record.
037     */
038    <T> T toObject(final Record data, Class<T> expected);
039
040    /**
041     * Simple mapper of data to record.
042     *
043     * @param data pojo to map to record.
044     * @param <T> the pojo type (optional).
045     * @return a record representing the pojo.
046     */
047    <T> Record toRecord(final T data);
048
049    /**
050     * Forward an entry from the source record if it exists.
051     *
052     * @param source the source record to read data from.
053     * @param builder the current builder to fill.
054     * @param sourceColumn the column name.
055     * @param entry the entry to use for the output column.
056     * @return true if the entry was forwarded.
057     */
058    boolean forwardEntry(Record source, Record.Builder builder, String sourceColumn, Schema.Entry entry);
059
060    /**
061     * Method providing a collector enabling to create a record from another one in a custom fashion.
062     *
063     * @param schema the schema of the record being built.
064     * @param fallbackRecord the source record used when the custom handler does not handle current entry.
065     * @param customHandler a processor of entry enabling to inject custom data in the record being built.
066     * @param beforeFinish a callback before the record is actually built, it enables to add data if not already there.
067     * @return a collector enabling to build a record.
068     */
069    Collector<Schema.Entry, Record.Builder, Record> toRecord(Schema schema, Record fallbackRecord,
070            BiFunction<Schema.Entry, Record.Builder, Boolean> customHandler,
071            BiConsumer<Record.Builder, Boolean> beforeFinish);
072
073    /**
074     * Shortcut to build a record using {@link RecordService#toRecord(Schema, Record, BiFunction, BiConsumer)}.
075     *
076     * @param schema the schema of the record being built.
077     * @param fallbackRecord the source record used when the custom handler does not handle current entry.
078     * @param customHandler a processor of entry enabling to inject custom data in the record being built.
079     * @param beforeFinish a callback before the record is actually built, it enables to add data if not already there.
080     * @return a collector enabling to build a record.
081     */
082    Record create(Schema schema, Record fallbackRecord, BiFunction<Schema.Entry, Record.Builder, Boolean> customHandler,
083            BiConsumer<Record.Builder, Boolean> beforeFinish);
084
085    /**
086     * Visit a record with a custom visitor.
087     *
088     * @param visitor the visitor to use to browse the record.
089     * @param record record to visit.
090     * @param <T> the visitor returned type.
091     * @return the visitor value.
092     */
093    <T> T visit(RecordVisitor<T> visitor, Record record);
094}