Java Reflection Assignable isAssignable(Class cls, final Class toClass)

Description

is Assignable

License

Apache License

Declaration

static boolean isAssignable(Class<?> cls, final Class<?> toClass) 

Method Source Code

//package com.java2s;
/*/*from w w  w.  jav a2  s.c  o m*/
 * 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.
 */

import java.util.HashMap;

import java.util.Map;

public class Main {
    private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<>();
    private static final Map<Class<?>, Class<?>> wrapperPrimitiveMap = new HashMap<>();

    static boolean isAssignable(Class<?> cls, final Class<?> toClass) {
        if (toClass == null) {
            return false;
        }
        // have to check for null, as isAssignableFrom doesn't
        if (cls == null) {
            return !toClass.isPrimitive();
        }
        //autoboxing:
        if (cls.isPrimitive() && !toClass.isPrimitive()) {
            cls = primitiveToWrapper(cls);
            if (cls == null) {
                return false;
            }
        }

        if (toClass.isPrimitive() && !cls.isPrimitive()) {
            cls = wrapperToPrimitive(cls);
            if (cls == null) {
                return false;
            }
        }
        if (cls.equals(toClass)) {
            return true;
        }
        if (cls.isPrimitive()) {
            if (!toClass.isPrimitive()) {
                return false;
            }
            if (Integer.TYPE.equals(cls)) {
                return Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
            }
            if (Long.TYPE.equals(cls)) {
                return Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
            }
            if (Boolean.TYPE.equals(cls)) {
                return false;
            }
            if (Double.TYPE.equals(cls)) {
                return false;
            }
            if (Float.TYPE.equals(cls)) {
                return Double.TYPE.equals(toClass);
            }
            if (Character.TYPE.equals(cls)) {
                return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
                        || Double.TYPE.equals(toClass);
            }
            if (Short.TYPE.equals(cls)) {
                return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
                        || Double.TYPE.equals(toClass);
            }
            if (Byte.TYPE.equals(cls)) {
                return Short.TYPE.equals(toClass) || Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass)
                        || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
            }
            // should never get here
            return false;
        }
        return toClass.isAssignableFrom(cls);
    }

    static Class<?> primitiveToWrapper(final Class<?> cls) {
        Class<?> convertedClass = cls;
        if (cls != null && cls.isPrimitive()) {
            convertedClass = primitiveWrapperMap.get(cls);
        }
        return convertedClass;
    }

    static Class<?> wrapperToPrimitive(final Class<?> cls) {
        return wrapperPrimitiveMap.get(cls);
    }
}

Related

1. isAssignable(Class clazz, Class toClass)
2. isAssignable(Class lhsType, Class rhsType)
3. isAssignable(Class lhsType, Class rhsType)
4. isAssignable(Class lhsType, Class rhsType)
5. isAssignable(Class lhsType, Class rhsType)
6. isAssignable(final Class from, final Class to)