org.codehaus.groovy.runtime.typehandling.ShortTypeHandling Maven / Gradle / Ivy

/*
 * Copyright 2003-2014 the original author or authors.
 *
 * 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.
 */
package org.codehaus.groovy.runtime.typehandling;

import groovy.lang.GString;

/**
 * Class providing various short paths for type conversions. Read the comments
 * to what conditions have to be met to get valid results!
 * Any method here must not depend on the groovy runtime.
 *
 * @author Jochen Theodorou
 */
public class ShortTypeHandling {

    public static Class castToClass(Object object) {
        if (object==null) return null;
        if (object instanceof Class) return (Class) object;
        try {
            return Class.forName(object.toString());
        } catch (Exception e) {
            throw new GroovyCastException(object, Class.class, e);
        }
    }

    public static String castToString(Object object) {
        if (object==null) return null;
        if (object instanceof Class) return (String) object;
        return object.toString();
    }

    /**
     * this class requires that the supplied enum is not fitting a 
     * Collection case for casting
     */
    public static Enum castToEnum(Object object, Class type) {
        if (object==null) return null;
        if (type.isInstance(object)) return (Enum) object;
        if (object instanceof String || object instanceof GString) {
            return Enum.valueOf(type, object.toString());
        }
        throw new GroovyCastException(object, type);
    }

    public static Character castToChar(Object object) {
        if (object==null) return null;
        if (object instanceof Character) {
            return ((Character) object).charValue();
        } else if (object instanceof Number) {
            Number value = (Number) object;
            return (char) value.intValue();
        }
        String text = object.toString();
        if (text.length() == 1) {
            return text.charAt(0);
        } else {
            throw new GroovyCastException(text,char.class);
        }
    }
}