com.github.protobufel.el.ELUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of protobufel-el Show documentation
ProtoBuf integration with EL 3.0
The newest version!
//
// Copyright © 2014, David Tesler (https://github.com/protobufel)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of the  nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL  BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//

package com.github.protobufel.el;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.el.ELContext;
import javax.el.ELException;

/**
 * EL Utilities.
 *
 * @author [email protected] David Tesler
 */
public final class ELUtil {
  private ELUtil() {}

  public static Object invokeMethod(final ELContext context, final Method m, final Object base,
      final Object[] params) {
    final Class[] parameterTypes = m.getParameterTypes();
    Object[] parameters = null;

    if (parameterTypes.length > 0) {
      if (m.isVarArgs() && (params.length < (parameterTypes.length - 1))) {
        throw new ELException(new IllegalArgumentException("wrong number of arguments"));
      }

      parameters = new Object[params.length];
      final int normalParamLength =
          m.isVarArgs() ? parameterTypes.length - 1 : parameterTypes.length;

      for (int i = 0; i < normalParamLength; i++) {
        parameters[i] = context.convertToType(params[i], parameterTypes[i]);
      }

      if (m.isVarArgs() && (params.length > normalParamLength)) {
        final Class varArgsType = parameterTypes[normalParamLength];

        for (int i = normalParamLength; i < params.length; i++) {
          parameters[i] = context.convertToType(params[i], varArgsType);
        }
      }
    }

    try {
      return m.invoke(base, parameters);
    } catch (final IllegalAccessException iae) {
      throw new ELException(iae);
    } catch (final InvocationTargetException ite) {
      throw new ELException(ite.getCause());
    }
  }

}