com.vectorprint.configuration.parameters.annotation.ParamAnnotationProcessorImpl Maven / Gradle / Ivy

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A library for settings and parameterization of objects. Key features are support for data types, help for settings and parameters, annotations for ease of use. Settings and parameters both are Clonable and Serializable. More features for settings such as parsing a settingsfile, being observable, readonliness, caching etc. are available. The library contains javacc generated parsers for syntax support for properties, multi valued properties, parameterized objects and multi valued parameters.

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package com.vectorprint.configuration.parameters.annotation;

/*-
 * #%L
 * Config
 * %%
 * Copyright (C) 2015 - 2018 VectorPrint
 * %%
 * 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.
 * #L%
 */

import com.vectorprint.configuration.binding.parameters.ParamBindingService;
import com.vectorprint.configuration.parameters.ParameterImpl;
import com.vectorprint.configuration.parameters.Parameterizable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.Arrays;

public class ParamAnnotationProcessorImpl implements ParamAnnotationProcessor {

   private static final Logger log = LoggerFactory.getLogger(ParamAnnotationProcessorImpl.class.getName());

   /**
    * Looks for parameter annotations on each class in the hierarchy and
    * {@link Parameterizable#addParameter(com.vectorprint.configuration.parameters.Parameter, java.lang.Class) adds a parameter to the parameterizable}
    * for each annotation found. Skips parameters already present on the parameterizable. This implementation assumes a
    * two argument constructor like {@link ParameterImpl#ParameterImpl(String, String, Class)}.
    *
    * @param parameterizable
    * @throws NoSuchMethodException
    * @throws InstantiationException
    * @throws IllegalAccessException
    * @throws InvocationTargetException
    */
   @Override
   public boolean initParameters(Parameterizable parameterizable) throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
      if (parameterizable.getSettings()==null||parameterizable.getSettings().isEmpty()) {
         log.warn(String.format("Initializing parameters of %s without settings, you may want to initialize settings of %s before initializing parameters",
             parameterizable.getClass().getName(),parameterizable.getClass().getName()));
      }
      Class c = parameterizable.getClass();
      while (Parameterizable.class.isAssignableFrom(c)) {
         if (log.isDebugEnabled()) {
            log.debug(String.format("looking for parameter annotations on %s", c.getName()));
         }
         process(c, parameterizable);
         c = c.getSuperclass();
      }
      return true;
   }

   private void process(Class c, Parameterizable parameterizable) throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
      Parameters annotation = c.getAnnotation(Parameters.class);
      if (annotation != null) {
          for (Param p : annotation.parameters()) {
            String key = p.key();
            if (parameterizable.getParameters().containsKey(key)) {
               if (log.isDebugEnabled()) {
                  log.debug(String.format("skipping parameter %s, already present on %s: %s", key, parameterizable.getClass().getName(), parameterizable.getParameters().get(key)));
               }
               continue;
            }
            String help = p.help();
            String def = (Param.NULL.equals(p.defaultValue())) ? null : p.defaultValue();
            String[] defArray = (Param.NULL.equals(p.defaultArray()[0])) ? null : p.defaultArray();
            Class pic = p.clazz();
            if (log.isDebugEnabled()) {
               log.debug(String.format("applying parameter %s with key %s and default %s on %s", pic.getName(), key, (def) == null ? Arrays.toString(defArray) : def, c.getName()));
            }
            Constructor con = pic.getConstructor(String.class, String.class);
            ParameterImpl pi = (ParameterImpl) con.newInstance(key, help);
            if (def != null) {
               pi.setDefault((Serializable) ParamBindingService.getInstance().getFactory().getBindingHelper().convert(def, pi.getValueClass()));
            } else if (defArray != null) {
               pi.setDefault((Serializable) ParamBindingService.getInstance().getFactory().getBindingHelper().convert(defArray, pi.getValueClass()));
            }
            parameterizable.addParameter(pi, c);
         }
      }
   }

}