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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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package javax.xml.bind.annotation.adapters;

/**

 * Built-in {@link XmlAdapter} to handle <tt>xs:token</tt> and its derived types.

 *

 * <p>

 * This adapter removes leading and trailing whitespaces, then truncate any

 *

 * @author Kohsuke Kawaguchi

 * @since 1.6, JAXB 2.0

 */

public class CollapsedStringAdapter extends XmlAdapter<String,String> {

    /**

     * Removes leading and trailing whitespaces of the string

     * given as the parameter, then truncate any

     */

    public String unmarshal(String text) {

        if(text==null)  return null;        // be defensive

        int len = text.length();

        // most of the texts are already in the collapsed form.

        // so look for the first whitespace in the hope that we will

        // never see it.

        int s=0;

        while(s<len) {

            if(isWhiteSpace(text.charAt(s)))

                break;

            s++;

        }

        if(s==len)

            // the input happens to be already collapsed.

            return text;

        // we now know that the input contains spaces.

        // let's sit down and do the collapsing normally.

        StringBuilder result = new StringBuilder(len /*allocate enough size to avoid re-allocation*/ );

        if(s!=0) {

            for( int i=0; i<s; i++ )

                result.append(text.charAt(i));

            result.append(' ');

        }

        boolean inStripMode = true;

        for (int i = s+1; i < len; i++) {

            char ch = text.charAt(i);

            boolean b = isWhiteSpace(ch);

            if (inStripMode && b)

                continue; // skip this character

            inStripMode = b;

            if (inStripMode)

                result.append(' ');

            else

                result.append(ch);

        }

        // remove trailing whitespaces

        len = result.length();

        if (len > 0 && result.charAt(len - 1) == ' ')

            result.setLength(len - 1);

        // whitespaces are already collapsed,

        // so all we have to do is to remove the last one character

        // if it's a whitespace.

        return result.toString();

    }

    /**

     * No-op.

     *

     * Just return the same string given as the parameter.

     */

    public String marshal(String s) {

        return s;

    }

    /** returns true if the specified char is a white space character. */

    protected static boolean isWhiteSpace(char ch) {

        // most of the characters are non-control characters.

        // so check that first to quickly return false for most of the cases.

        if( ch>0x20 )   return false;

        // other than we have to do four comparisons.

        return ch == 0x9 || ch == 0xA || ch == 0xD || ch == 0x20;

    }

}