Java String Explode explodeQuoted(String arg)

Description

Split a string up by whitespace, taking into account quoted subcomponents.

License

Open Source License

Parameter

Parameter	Description
arg	String to parse

Exception

Parameter	Description
IllegalArgumentException	indicating there was a quoting error

Return

an array of elements, the argument was split into

Declaration

public static String[] explodeQuoted(String arg) 

Method Source Code

//package com.java2s;
/*//from  w w w.  ja  v a2  s .co m
 * NOTE: This copyright does *not* cover user programs that use HQ
 * program services by normal system calls through the application
 * program interfaces provided as part of the Hyperic Plug-in Development
 * Kit or the Hyperic Client Development Kit - this is merely considered
 * normal use of the program, and does *not* fall under the heading of
 * "derived work".
 * 
 * Copyright (C) [2004-2008], Hyperic, Inc.
 * This file is part of HQ.
 * 
 * HQ is free software; you can redistribute it and/or modify
 * it under the terms version 2 of the GNU General Public License as
 * published by the Free Software Foundation. This program is distributed
 * in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA.
 */

import java.util.ArrayList;

import java.util.List;

public class Main {
    private static final char QUOTE = '\'';
    private static final char DOUBLEQUOTE = '"';
    private static final char BACKSLASH = '\\';

    /**
     * Split a string up by whitespace, taking into account quoted
     * subcomponents.  If there is an uneven number of quotes, a
     * parse error will be thrown.
     *
     * @param arg String to parse
     * @return an array of elements, the argument was split into
     * @throws IllegalArgumentException indicating there was a quoting error
     */
    public static String[] explodeQuoted(String arg) {
        return splitCommandLine(arg, true);
    }

    private static String[] splitCommandLine(String str, boolean extract) {
        List list = new ArrayList();
        int slen;
        char c;
        int i = 0;
        int tokstart = 0;

        if ((str == null) || ((str = str.trim()).length() == 0)) {
            return new String[0];
        }

        slen = str.length();

        while (true) {
            if (i < slen) {
                c = str.charAt(i);
            } else {
                c = '\0';
            }

            if (c == BACKSLASH) {
                i++;
                if (i < slen) {
                    i++;
                }
            } else if (c == QUOTE) {
                i = skipSingleQuoted(str, slen, ++i);
            } else if (c == DOUBLEQUOTE) {
                i = skipDoubleQuoted(str, slen, ++i);
            } else if ((c == '\0') || spctabnl(c)) {
                String token = str.substring(tokstart, i);
                if (extract) {
                    token = extractQuoted(token);
                }
                list.add(token);
                while ((i < slen) && spctabnl(str.charAt(i))) {
                    i++;
                }
                if (i < slen) {
                    tokstart = i;
                } else {
                    break;
                }
            } else {
                i++;
            }
        }
        return (String[]) list.toArray(new String[list.size()]);
    }

    private static int skipSingleQuoted(String str, int slen, int sind) {
        int i = sind;

        while ((i < slen) && str.charAt(i) != QUOTE) {
            i++;
        }
        if (i < slen) {
            i++;
        }
        return i;
    }

    private static int skipDoubleQuoted(String str, int slen, int sind) {
        int i = sind;
        int pass_next = 0;

        while (i < slen) {
            char c = str.charAt(i);
            if (pass_next != 0) {
                pass_next = 0;
                i++;
            } else if (c == BACKSLASH) {
                pass_next++;
                i++;
            } else if (c != DOUBLEQUOTE) {
                i++;
            } else {
                break;
            }
        }

        if (i < slen) {
            i++;
        }
        return i;
    }

    private static boolean spctabnl(char c) {
        return (c == ' ') || (c == '\t') || (c == '\n');
    }

    public static String extractQuoted(String str) {
        if (str.length() == 0) {
            return str;
        }
        if (str.charAt(0) == QUOTE) {
            str = extractSingleQuoted(str);
        } else if (str.charAt(0) == DOUBLEQUOTE) {
            str = extractDoubleQuoted(str);
        }
        return str;
    }

    private static String extractSingleQuoted(String str) {
        char first = str.charAt(0);
        char last = str.charAt(str.length() - 1);
        if (first == QUOTE) {
            if (last == QUOTE) {
                return str.substring(1, str.length() - 1);
            } else {
                throw new IllegalArgumentException("Unbalanced quotation marks");
            }
        } else {
            return str;
        }
    }

    private static String extractDoubleQuoted(String str) {
        int slen = str.length();
        int i = 0;
        int pass_next = 0;
        int dquote = 0;
        StringBuffer temp = new StringBuffer(slen);

        while (i < slen) {
            char c = str.charAt(i);
            if (pass_next != 0) {
                if (dquote == 0) {
                    temp.append('\\');
                }
                pass_next = 0;
                temp.append(c);
            } else if (c == BACKSLASH) {
                pass_next++;
            } else if (c != DOUBLEQUOTE) {
                temp.append(c);
            } else {
                dquote ^= 1;
            }
            i++;
        }

        if (dquote != 0) {
            throw new IllegalArgumentException("Unbalanced quotation marks");
        }

        return temp.toString();
    }
}

Related

1. explode(String tokenizer, String text)
2. explode(String[] elements, String separator)
3. explodeCamelCase(String str, boolean excludeGetOrSet)
4. explodeDomains(final String fqdn)
5. explodeLongs(String line, String sep)