Java String Starts Wtih startsWithURIScheme(String arg)

Description

Determines if a prefix of the specified String is conform to an URI definition.

License

Apache License

Declaration

public static boolean startsWithURIScheme(String arg) 

Method Source Code

//package com.java2s;
/*   // w w  w.j  a  v  a 2s . c  om
   Copyright 2007-2014 Fraunhofer IGD, http://www.igd.fraunhofer.de
   Fraunhofer-Gesellschaft - Institute for Computer Graphics Research
       
   See the NOTICE file distributed with this work for additional 
   information regarding copyright ownership
       
   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.
 */

public class Main {
    /**
     * Determines if a prefix of the specified String is conform to an URI
     * definition. The following conditions are checked:
     * <ul>
     * <li>the String starts with a letter ([a-z,A-Z])</li>
     * <li>the String contains the symbol ':'</li>
     * <li>all characters from the beginning to the symbol ':' are either a
     * letter, a digit, or one of [+, -, .]</li>
     * </ul>
     */
    public static boolean startsWithURIScheme(String arg) {
        if (arg == null || arg.length() == 0)
            return false;

        char c = arg.charAt(0);
        int i = arg.indexOf(':');
        if (i < 1 || !isAsciiLetter(c))
            return false;

        while (--i > 0) {
            c = arg.charAt(i);
            if (!isAsciiLetter(c) && !isDigit(c) && c != '+' && c != '-' && c != '.')
                return false;
        }

        return true;
    }

    /** Determines if the specified character is a letter [a-z,A-Z]. */
    public static boolean isAsciiLetter(char c) {
        return (c >= 'A' && c <= 'Z') || (c <= 'z' && c >= 'a');
    }

    /** Determines if the specified character is a digit [0-9]. */
    public static boolean isDigit(char c) {
        return c >= '0' && c <= '9';
    }
}

Related

1. startsWithSpace(String s)
2. startsWithSpaces(final String text)
3. startsWithTag(String html, int position)
4. startsWithUppercase(String str)
5. startsWithUpperCase(String text)
6. startsWithVowel(String string)
7. startsWithVowel(String text)
8. startsWithVowel(String value)
9. startsWithVowel(String word)