CSVReaderBuilder

/*
 Copyright 2005 Bytecode Pty Ltd.

 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 com.opencsv;


import com.opencsv.enums.CSVReaderNullFieldIndicator;
import com.opencsv.processor.RowProcessor;
import com.opencsv.validators.LineValidator;
import com.opencsv.validators.RowValidator;
import org.apache.commons.lang3.ObjectUtils;

import java.io.Reader;
import java.util.Locale;
import java.util.ResourceBundle;

/**
 * Builder for creating a {@link CSVReader}.
 * <p>This should be the preferred method of creating a Reader as there are so many
 * possible values to be set it is impossible to have constructors for all of
 * them and keep backwards compatibility with previous constructors.<br>
 *
 * <code>
 * final CSVParser parser =<br>
 * new CSVParserBuilder()<br>
 * .withSeparator('\t')<br>
 * .withIgnoreQuotations(true)<br>
 * .build();<br>
 * final CSVReader reader =<br>
 * new CSVReaderBuilder(new StringReader(csv))<br>
 * .withSkipLines(1)<br>
 * .withCSVParser(parser)<br>
 * .build();<br>
 * </code></p>
 *
 * @see com.opencsv.CSVReader
 */
public class CSVReaderBuilder extends CSVReaderBaseBuilder<CSVReader> {

    /**
     * Sets the reader to an underlying CSV source.
     *
     * @param reader The reader to an underlying CSV source.
     */
    public CSVReaderBuilder(
            final Reader reader) {
        super(reader);
        if (reader == null) {
            throw new IllegalArgumentException(ResourceBundle.getBundle(ICSVParser.DEFAULT_BUNDLE_NAME).getString("reader.null"));
        }
    }

    /**
     * Sets the number of lines to skip before reading.
     *
     * @param skipLines The number of lines to skip before reading.
     * @return {@code this}
     */
    public CSVReaderBuilder withSkipLines(
            final int skipLines) {
        this.skipLines = Math.max(skipLines, 0);
        return this;
    }

    /**
     * Sets the parser to use to parse the input.
     *
     * @param icsvParser The parser to use to parse the input.
     * @return {@code this}
     */
    public CSVReaderBuilder withCSVParser(
            final ICSVParser icsvParser) {
        this.icsvParser = icsvParser;
        return this;
    }

    /**
     * Creates the {@link CSVReader}.
     * @return The {@link CSVReader} based on the set criteria.
     */
    @Override
    public CSVReader build() {
        final ICSVParser parser = getOrCreateCsvParser();
        return new CSVReader(reader, skipLines, parser, keepCR, verifyReader, multilineLimit, errorLocale,
                lineValidatorAggregator, rowValidatorAggregator, rowProcessor);
    }

    /**
     * Sets if the reader will keep or discard carriage returns.
     *
     * @param keepCR True to keep carriage returns, false to discard.
     * @return {@code this}
     */
    public CSVReaderBuilder withKeepCarriageReturn(boolean keepCR) {
        this.keepCR = keepCR;
        return this;
    }

    /**
     * Checks to see if the {@link CSVReader} should verify the reader state before
     * reads or not.
     *
     * <p>This should be set to false if you are using some form of asynchronous
     * reader (like readers created by the java.nio.* classes).</p>
     *
     * <p>The default value is true.</p>
     *
     * @param verifyReader True if {@link CSVReader} should verify reader before each read, false otherwise.
     * @return {@code this}
     */
    public CSVReaderBuilder withVerifyReader(boolean verifyReader) {
        this.verifyReader = verifyReader;
        return this;
    }

    /**
     * Checks to see if it should treat a field with two separators, two quotes, or both as a null field.
     *
     * @param indicator {@link CSVReaderNullFieldIndicator} set to what should be considered a null field.
     * @return {@code this}
     */
    public CSVReaderBuilder withFieldAsNull(CSVReaderNullFieldIndicator indicator) {
        this.nullFieldIndicator = indicator;
        return this;
    }

    /**
     * Sets the maximum number of lines allowed in a multiline record.
     * More than this number in one record results in an IOException.
     *
     * @param multilineLimit No more than this number of lines is allowed in a
     *                       single input record. The default is {@link CSVReader#DEFAULT_MULTILINE_LIMIT}.
     * @return {@code this}
     */
    public CSVReaderBuilder withMultilineLimit(int multilineLimit) {
        this.multilineLimit = multilineLimit;
        return this;
    }

    /**
     * Sets the locale for all error messages.
     *
     * @param errorLocale Locale for error messages
     * @return {@code this}
     * @since 4.0
     */
    public CSVReaderBuilder withErrorLocale(Locale errorLocale) {
        this.errorLocale = ObjectUtils.defaultIfNull(errorLocale, Locale.getDefault());
        return this;
    }

    /**
     * Adds a {@link LineValidator} to the {@link CSVReader}.
     * Multiple {@link LineValidator}s can be added with multiple calls.
     *
     * @param lineValidator {@link LineValidator} to inject.
     * @return {@code this}
     * @since 5.0
     */
    public CSVReaderBuilder withLineValidator(LineValidator lineValidator) {
        lineValidatorAggregator.addValidator(lineValidator);
        return this;
    }

    /**
     * Adds a {@link RowValidator} to the {@link CSVReader}.
     * Multiple {@link RowValidator}s can be added with multiple calls.
     *
     * @param rowValidator {@link RowValidator} to inject
     * @return {@code this}
     * @since 5.0
     */
    public CSVReaderBuilder withRowValidator(RowValidator rowValidator) {
        rowValidatorAggregator.addValidator(rowValidator);
        return this;
    }

    /**
     * Adds a {@link RowProcessor} to the {@link CSVReader}.
     * Only a single {@link RowProcessor} can be added so multiple calls will overwrite
     * the previously set {@link RowProcessor}.
     *
     * @param rowProcessor {@link RowProcessor} to inject
     * @return {@code this}
     * @since 5.0
     */
    public CSVReaderBuilder withRowProcessor(RowProcessor rowProcessor) {
        this.rowProcessor = rowProcessor;
        return this;
    }
}