Java String Split by Quote splitSafeQuote(String input, char separator)

Description

Splits the input safely honoring if values is enclosed in quotes.

License

Apache License

Parameter

Parameter	Description
input	the input
separator	the separator char to split the input, for example a comma.

Return

the input splitted, or null if the input is null.

Declaration

public static String[] splitSafeQuote(String input, char separator) 

Method Source Code

//package com.java2s;
/**//www . jav  a 2s .  c om
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

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

public class Main {
    /**
     * Splits the input safely honoring if values is enclosed in quotes.
     * <p/>
     * Though this method does not support double quoting values. A quoted value
     * must start with the same start and ending quote, which is either a single
     * quote or double quote value.
     * <p/>
     * Will <i>trim</i> each splitted value by default.
     *
     * @param input    the input
     * @param separator the separator char to split the input, for example a comma.
     * @return the input splitted, or <tt>null</tt> if the input is null.
     */
    public static String[] splitSafeQuote(String input, char separator) {
        return splitSafeQuote(input, separator, true);
    }

    /**
     * Splits the input safely honoring if values is enclosed in quotes.
     * <p/>
     * Though this method does not support double quoting values. A quoted value
     * must start with the same start and ending quote, which is either a single
     * quote or double quote value.
     * \
     * @param input    the input
     * @param separator the separator char to split the input, for example a comma.
     * @param trim      whether to trim each splitted value
     * @return the input splitted, or <tt>null</tt> if the input is null.
     */
    public static String[] splitSafeQuote(String input, char separator, boolean trim) {
        if (input == null) {
            return null;
        }

        if (input.indexOf(separator) == -1) {
            // no separator in data, so return single string with input as is
            return new String[] { trim ? input.trim() : input };
        }

        List<String> answer = new ArrayList<String>();
        StringBuilder sb = new StringBuilder();

        boolean singleQuoted = false;
        boolean doubleQuoted = false;
        boolean skipLeadingWhitespace = true;

        for (int i = 0; i < input.length(); i++) {
            char ch = input.charAt(i);
            char prev = i > 0 ? input.charAt(i - 1) : 0;
            boolean isQuoting = singleQuoted || doubleQuoted;

            if (!doubleQuoted && ch == '\'') {
                if (singleQuoted && prev == ch && sb.length() == 0) {
                    // its an empty quote so add empty text
                    answer.add("");
                }
                // special logic needed if this quote is the end
                if (i == input.length() - 1) {
                    if (singleQuoted && sb.length() > 0) {
                        String text = sb.toString();
                        // do not trim a quoted string
                        answer.add(text);
                        sb.setLength(0);
                    }
                }
                singleQuoted = !singleQuoted;
                continue;
            } else if (!singleQuoted && ch == '"') {
                if (doubleQuoted && prev == ch && sb.length() == 0) {
                    // its an empty quote so add empty text
                    answer.add("");
                }
                // special logic needed if this quote is the end
                if (i == input.length() - 1) {
                    if (doubleQuoted && sb.length() > 0) {
                        String text = sb.toString();
                        // do not trim a quoted string
                        answer.add(text);
                        sb.setLength(0);
                    }
                }
                doubleQuoted = !doubleQuoted;
                continue;
            } else if (!isQuoting && ch == ' ') {
                if (skipLeadingWhitespace) {
                    continue;
                }
            } else if (!isQuoting && ch == separator) {
                // add as answer if we are not in a quote
                if (sb.length() > 0) {
                    String text = sb.toString();
                    if (trim) {
                        text = text.trim();
                    }
                    answer.add(text);
                    sb.setLength(0);
                }
                // we should avoid adding the separator 
                continue;
            }

            sb.append(ch);
        }

        // any leftover
        if (sb.length() > 0) {
            String text = sb.toString();
            if (trim) {
                text = text.trim();
            }
            answer.add(text);
        }

        return answer.toArray(new String[answer.size()]);
    }
}

Related

1. splitQuotedEscape(String src)
2. splitQuotedStr(String str, char delimiter, char quote, boolean trim)
3. splitQuotedString(String str)
4. splitQuotedString(String str)
5. splitQuotedTokens(String str)
6. splitShifted(int[] shiftedQuoteString)
7. splitStringWithQuotes(String in)
8. splitWithQuotes(String s)