org.simpleflatmapper.lightningcsv.CsvCellWriter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of lightning-csv Show documentation
Java library to map flat record - ResultSet, csv - to java object with minimum configuration and low footprint.
The newest version!
package org.simpleflatmapper.lightningcsv;


import org.simpleflatmapper.util.CharSequenceImpl;

import java.io.IOException;
import java.util.Iterator;

public final class CsvCellWriter implements CellWriter {

    public static final char DEFAULT_SEPARATOR = ',';
    public static final char DEFAULT_QUOTE = '"';
    public static final char DEFAULT_ESCAPE = '"';
    public static final boolean DEFAULT_ALWAYS_ESCAPE = false;
    public static final String DEFAULT_END_OF_LINE = "\r\n";

    public static final CsvCellWriter DEFAULT_WRITER = new CsvCellWriter(DEFAULT_SEPARATOR, DEFAULT_QUOTE, DEFAULT_ESCAPE, DEFAULT_ALWAYS_ESCAPE, DEFAULT_END_OF_LINE);

    private final boolean alwaysEscape;
    private final char separator;
    private final char quote;
    private final char escape;
    private final String endOfLine;
    private final char[] specialCharacters;

    public CsvCellWriter(char separator, char quote, char escape, boolean alwaysEscape, String endOfLine) {
        this.separator = separator;
        this.quote = quote;
        this.escape = escape;
        this.alwaysEscape = alwaysEscape;
        this.endOfLine = endOfLine;
        this.specialCharacters = (getSpecialCharacterForEndOfLine(endOfLine) + quote + separator).toCharArray();
    }

    private String getSpecialCharacterForEndOfLine(String endOfLine) {
        if ("\n".equals(endOfLine) || "\r".equals(endOfLine)) {
            return "\r\n";
        }
        return endOfLine;
    }

    public void writeRow(CharSequence[] values, Appendable appendable) throws IOException {
        if (values != null && values.length > 0) {
            writeValue(values[0], appendable);

            for(int i = 1; i < values.length; i++) {
                nextCell(appendable);
                writeValue(values[1], appendable);
            }
        }
        endOfRow(appendable);
    }

    public void writeRow(Iterable values, Appendable appendable) throws IOException {
        Iterator iterator = values.iterator();
        if (iterator.hasNext()) {
            writeValue(iterator.next(), appendable);

            while(iterator.hasNext()) {
                nextCell(appendable);
                writeValue(iterator.next(), appendable);
            }
        }
        endOfRow(appendable);
    }


    @Override
    public void writeValue(CharSequence sequence, Appendable appendable) throws IOException {
        writeValue(sequence, 0, sequence.length(), appendable);
    }

    @Override
    public void writeValue(CharSequence sequence, int start, int end, Appendable appendable) throws IOException {
        if (sequence != null) {
            if (alwaysEscape || needsEscaping(sequence, start, end)) {
                escapeCharSequence(sequence, start, end, appendable);
            } else {
                appendable.append(sequence, start, end);
            }
        }
    }

    @Override
    public void writeValue(char[] chars, int start, int end, Appendable appendable) throws IOException {
        if (chars != null) {
            writeValue(new CharSequenceImpl(chars, start, end), appendable);
        }
    }

    private boolean needsEscaping(CharSequence sequence, int start, int end) {
        char[] specialCharacters = this.specialCharacters;
        for(int i = start; i < end; i++) {
            char c = sequence.charAt(i);
            for(int j = 0; j < specialCharacters.length; j++) {
                char s = specialCharacters[j];
                if (c == s) return true;
            }
        }
        return false;
    }

    private void escapeCharSequence(CharSequence sequence, int start, int end, Appendable appendable) throws IOException {
        char quote = this.quote;
        appendable.append(quote);
        for(int i = start; i < end; i++) {
            char c = sequence.charAt(i);
            if (c == quote) {
                appendable.append(escape);
            }
            appendable.append(c);
        }
        appendable.append(quote);
    }

    @Override
    public void nextCell(Appendable target) throws IOException {
        target.append(separator);
    }

    @Override
    public void endOfRow(Appendable target) throws IOException {
        target.append(endOfLine);
    }

    public CsvCellWriter separator(char separator) {
        return new CsvCellWriter(separator, quote, escape, alwaysEscape, endOfLine);
    }
    public CsvCellWriter quote(char quote) {
        return new CsvCellWriter(separator, quote, escape, alwaysEscape, endOfLine);
    }
    public CsvCellWriter escape(char escape) {
        return new CsvCellWriter(separator, quote, escape, alwaysEscape, endOfLine);
    }
    public CsvCellWriter alwaysEscape(boolean alwaysEscape) {
        return new CsvCellWriter(separator, quote, escape, alwaysEscape, endOfLine);
    }

    public CsvCellWriter endOfLine(String endOfLine) {
        return new CsvCellWriter(separator, quote, escape, alwaysEscape, endOfLine);
    }

    public CellWriter alwaysEscape() {
        return alwaysEscape(true);
    }

}