jodd.util.CsvUtil Maven / Gradle / Ivy

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// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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package jodd.util;

import java.util.ArrayList;
import java.util.List;

/**
 * Helps with CSV strings.
 * See: http://en.wikipedia.org/wiki/Comma-separated_values
 */
public class CsvUtil {

    protected static final char FIELD_SEPARATOR = ',';
    protected static final char FIELD_QUOTE = '"';
    protected static final String DOUBLE_QUOTE = "\"\"";
    protected static final String SPECIAL_CHARS = "\r\n";

    /**
     * Parse fields as csv string,
     */
    public static String toCsvString(Object... elements) {
        StringBuilder line = new StringBuilder();
        int last = elements.length - 1;
        for (int i = 0; i < elements.length; i++) {
            if (elements[i] == null) {
                if (i != last) {
                    line.append(FIELD_SEPARATOR);
                }
                continue;
            }
            String field = elements[i].toString();

            // check for special cases
            int ndx = field.indexOf(FIELD_SEPARATOR);
            if (ndx == -1) {
                ndx = field.indexOf(FIELD_QUOTE);
            }
            if (ndx == -1) {
                if (field.startsWith(StringPool.SPACE) || field.endsWith(StringPool.SPACE)) {
                    ndx = 1;
                }
            }
            if (ndx == -1) {
                ndx = StringUtil.indexOfChars(field, SPECIAL_CHARS);
            }

            // add field
            if (ndx != -1) {
                line.append(FIELD_QUOTE);
            }
            field = StringUtil.replace(field, StringPool.QUOTE, DOUBLE_QUOTE);
            line.append(field);
            if (ndx != -1) {
                line.append(FIELD_QUOTE);
            }

            // last
            if (i != last) {
                line.append(FIELD_SEPARATOR);
            }
        }
        return line.toString();
    }


    /**
     * Converts CSV line to string array.
     */
    public static String[] toStringArray(String line) {
        List row = new ArrayList<>();

        boolean inQuotedField = false;
        int fieldStart = 0;

        final int len = line.length();
        for (int i = 0; i < len; i++) {
            char c = line.charAt(i);
            if (c == FIELD_SEPARATOR) {
                if (!inQuotedField) {    // ignore we are quoting
                    addField(row, line, fieldStart, i, inQuotedField);
                    fieldStart = i + 1;
                }
            } else if (c == FIELD_QUOTE) {
                if (inQuotedField) {
                    if (i + 1 == len || line.charAt(i + 1) == FIELD_SEPARATOR) {    // we are already quoting - peek to see if this is the end of the field
                        addField(row, line, fieldStart, i, inQuotedField);
                        fieldStart = i + 2;
                        i++; // and skip the comma
                        inQuotedField = false;
                    }
                } else if (fieldStart == i) {
                    inQuotedField = true;    // this is a beginning of a quote
                    fieldStart++;            // move field start
                }
            }
        }
        // add last field - but only if string was not empty
        if (len > 0 && fieldStart <= len) {
            addField(row, line, fieldStart, len, inQuotedField);
        }
        return row.toArray(new String[row.size()]);
    }

    private static void addField(List row, String line, int startIndex, int endIndex, boolean inQuoted) {
        String field = line.substring(startIndex, endIndex);
        if (inQuoted) {
            field = StringUtil.replace(field, DOUBLE_QUOTE, "\"");
        }
        row.add(field);
    }

}