org.ualerts.fixed.service.commands.AbstractCommand.java Source code

Introduction

Here is the source code for org.ualerts.fixed.service.commands.AbstractCommand.java

Source

/*
 * File created on May 1, 2013 
 *
 * Copyright 2008-2013 Virginia Polytechnic Institute and State University
 *
 * 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.ualerts.fixed.service.commands;

import org.springframework.beans.factory.InitializingBean;
import org.ualerts.fixed.service.Command;

/**
 * An abstract base for {@link Command} implementations.
 * @param <T> defines the type of the command
 * @author Carl Harris
 */
public abstract class AbstractCommand<T> implements Command<T>, InitializingBean {

    /**
     * {@inheritDoc}
     */
    public void afterPropertiesSet() throws Exception {
    }

    /**
     * {@inheritDoc}
     */
    public final T execute() throws Exception {
        onValidate();
        return onExecute();
    }

    /**
     * Performs any required validation of command state and member parameters.
     * @throws Exception as needed.
     */
    protected void onValidate() throws Exception {
    }

    /**
     * Performs the execution of the command.
     * @return a reference to the object the command uses, as appropriate.
     * @throws Exception as needed.
     */
    protected abstract T onExecute() throws Exception;

}