Java Reflection Method Parameter getMethod(Class target, String methodName, Class[] parameterTypes)

Description

get Method

License

Open Source License

Declaration

public static Method getMethod(Class target, String methodName, Class[] parameterTypes) 

Method Source Code

//package com.java2s;
/**/*from w  w w  . j  a v  a  2 s  . c o m*/
 *
 * Licensed under the GNU General Public License (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.gnu.org/licenses/gpl.txt
 *
 * 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.
 *
 * 
 * @author Vadim Kisen
 *
 * copyright 2010 by uTest 
 */

import java.lang.reflect.Method;

public class Main {
    public static Method getMethod(Class target, String methodName, Class[] parameterTypes) {
        return findMethod(target.getClass().getMethods(), methodName, parameterTypes);
    }

    public static Method getMethod(Class target, String methodName, Object[] parameters) {
        return getMethod(target, methodName, fromObjectsToClasses(parameters));
    }

    public static Method findMethod(Method[] methods, String methodName, Class[] parameterTypes) {
        Method method = null;
        for (Method methodCandidate : methods) {
            if (!methodCandidate.getName().equals(methodName)) {
                continue;
            }
            Class[] params = methodCandidate.getParameterTypes();
            if (params.length != parameterTypes.length) {
                continue;
            }
            boolean isOk = true;
            for (int i = 0; i < params.length; i++) {
                if (parameterTypes[i].isPrimitive()) {
                    if (parameterTypes[i].equals(int.class) && params[i].equals(Integer.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(double.class) && params[i].equals(Double.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(float.class) && params[i].equals(Float.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(long.class) && params[i].equals(Long.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(boolean.class) && params[i].equals(Boolean.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(byte.class) && params[i].equals(Byte.class)) {
                        continue;
                    }
                    if (parameterTypes[i].equals(short.class) && params[i].equals(Short.class)) {
                        continue;
                    }
                } else if (!params[i].isAssignableFrom(parameterTypes[i])) {
                    isOk = false;
                    break;
                }
            }
            if (isOk) {
                method = methodCandidate;
                break;
            }
        }
        return method;

    }

    public static Method findMethod(Method[] methods, String methodName, Object[] parameters) {
        return findMethod(methods, methodName, fromObjectsToClasses(parameters));
    }

    public static Class[] fromObjectsToClasses(Object[] parameters) {
        Class[] parameterTypes = new Class[parameters.length];
        for (int i = 0; i < parameters.length; i++) {
            if (parameters[i] != null) {
                parameterTypes[i] = parameters[i].getClass();
            } else {
                parameterTypes[i] = Object.class;
            }
        }
        return parameterTypes;
    }
}

Related

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2. getMethod(Class clazz, String name, Class... parameterTypes)
3. getMethod(Class clazz, String name, Class[] parameters)
4. getMethod(Class declaringClass, String name, Class... parameterTypes)
5. getMethod(Class klass, String methodName, Class[] parameterTypes)
6. getMethod(Class type, String methodName, Class... parameterTypes)
7. getMethod(Class type, String name, Class[] parameterTypes)
8. getMethod(Class c, String methodName, Class... parameterTypes)
9. getMethod(Class clazz, String functionName, Class[] parameterTypes)