org.openestate.io.core.CsvPrinter.java Source code

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Here is the source code for org.openestate.io.core.CsvPrinter.java

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/*
 * Copyright 2015-2016 OpenEstate.org.
 *
 * 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 org.openestate.io.core;

import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.csv.CSVPrinter;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;

/**
 * A general CSV printer, that is bound to a {@link CsvFormat} and writes CSV
 * data from {@link CsvRecord} objects.
 *
 * @param <Record>
 * the class used for a record, that is printed to a CSV file
 *
 * @since 1.0
 * @author Andreas Rudolph
 */
public abstract class CsvPrinter<Record extends CsvRecord> implements Closeable, Flushable {
    //private final static Logger LOGGER = LoggerFactory.getLogger( CsvPrinter.class );
    private final static Pattern LINES = Pattern.compile("^(.*)$", Pattern.MULTILINE);
    private final CSVPrinter printer;

    /**
     * Create with specifications of a {@link CSVPrinter}.
     *
     * @param printer
     * the CSV printer from
     * <a href="http://commons.apache.org/proper/commons-csv/">commons-csv</a>
     */
    protected CsvPrinter(CSVPrinter printer) {
        this.printer = printer;
    }

    /**
     * Closes the printer instance.
     *
     * @throws IOException
     * if closing failed
     */
    @Override
    public void close() throws IOException {
        this.printer.close();
    }

    /**
     * Closes the printer instance without throwing exceptions.
     */
    public final void closeQuietly() {
        IOUtils.closeQuietly(this);
    }

    /**
     * Flushes the printer instance.
     *
     * @throws IOException
     * if flushing failed
     */
    @Override
    public void flush() throws IOException {
        this.printer.flush();
    }

    /**
     * Prints a single CSV value.
     *
     * @param value
     * CSV value to print
     *
     * @throws IOException
     * if printing failed
     */
    protected void print(String value) throws IOException {
        this.printer.print(value);
    }

    /**
     * Prints a record separator (line break).
     *
     * @throws IOException
     * if printing failed
     */
    protected void println() throws IOException {
        this.printer.println();
    }

    /**
     * Prints a comment.
     *
     * @param comment
     * comment to print
     *
     * @throws IOException
     * if printing failed
     */
    protected void printComment(String comment) throws IOException {
        this.printer.printComment(comment);
    }

    /**
     * Print a {@link CsvRecord} followed by a record separator (line break).
     *
     * @param record
     * record to print
     *
     * @throws IOException
     * if printing failed
     */
    public void printRecord(Record record) throws IOException {
        for (String value : record.print()) {
            this.print(value);
        }
        this.println();
    }

    /**
     * Print multiple {@link CsvRecord} objects.
     *
     * @param records
     * records to print
     *
     * @throws IOException
     * if printing failed
     */
    public void printRecords(Iterable<Record> records) throws IOException {
        for (Record record : records) {
            this.printRecord(record);
        }
        this.flush();
    }

    /**
     * Helper function to replace line breaks in a string with &lt;br/&gt; before
     * printing.
     * <p>
     * This method may be used by inheriting classes, if the particular format
     * does not support line breaks.
     *
     * @param value
     * value to replace
     *
     * @return
     * value with replaced line breaks
     */
    protected static String replaceLineBreaks(String value) {
        return replaceLineBreaks(value, null);
    }

    /**
     * Helper function to replace line breaks in a string with a custom value
     * before printing.
     * <p>
     * This method may be used by inheriting classes, if the particular format
     * does not support line breaks.
     *
     * @param value
     * value to replace
     *
     * @param lineBreak
     * value, that is used for replacement of line breaks - if null, &lt;br/&gt;
     * is used
     *
     * @return
     * value with replaced line breaks
     */
    protected static String replaceLineBreaks(String value, String lineBreak) {
        value = StringUtils.trimToNull(value);
        if (value == null)
            return null;
        if (lineBreak == null)
            lineBreak = "<br/>";
        Matcher m = LINES.matcher(value);
        StringBuilder out = new StringBuilder();
        while (m.find()) {
            out.append(StringUtils.trimToEmpty(m.group()));
            if (!m.hitEnd())
                out.append(lineBreak);
        }
        return out.toString();
    }
}