BidiStringConverter.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.utility.string;


/**
 * Used by various "pluggable" classes to transform objects
 * into strings and vice versa.
 *
 * If anyone can come up with a better class name
 * and/or method name, I would love to hear it.  -bjv
 */
public interface BidiStringConverter extends StringConverter {

    /**
     * Convert the specified string into an object.
     * The semantics of "convert to object" is determined by the
     * contract between the client and the server.
     * Typically, if the string is null, null is returned.
     */
    Object convertToObject(String s);


    BidiStringConverter DEFAULT_INSTANCE =
        new BidiStringConverter() {
            /** Return the object's #toString() result. */
            public String convertToString(Object o) {
                return (o == null) ? null : o.toString();
            }
            /** Return the string as the object. */
            public Object convertToObject(String s) {
                return s;
            }
            public String toString() {
                return "DefaultBidiStringConverter";
            }
        };

    BidiStringConverter BOOLEAN_CONVERTER =
        new BidiStringConverter() {
            /** Return "true" if the Boolean is true, otherwise return "false". */
            public String convertToString(Object o) {
                return (o == null) ? null : o.toString();
            }
            /** Return Boolean.TRUE if the string is "true" (case-insensitive), otherwise return Boolean.FALSE. */
            public Object convertToObject(String s) {
                return (s == null) ? null : Boolean.valueOf(s);
            }
            public String toString() {
                return "BooleanBidiStringConverter";
            }
        };

    BidiStringConverter INTEGER_CONVERTER =
        new BidiStringConverter() {
            /** Integer's #toString() works well. */
            public String convertToString(Object o) {
                return (o == null) ? null : o.toString();
            }
            /** Convert the string to an Integer, if possible. */
            public Object convertToObject(String s) {
                return (s == null) ? null : Integer.valueOf(s);
            }
            public String toString() {
                return "IntegerBidiStringConverter";
            }
        };

}