ReflectionUtils.java

/* vim: set ts=2 et sw=2 cindent fo=qroca: */

package com.globant.katari.tools;

import java.lang.reflect.Field;

/** Convenience methods to deal with reflection.
 *
 * This class includes operations to obtain and set the value of private
 * fields. It looks for them up in the class hierarchy.
 *
 * @deprecated use spring's DirectFieldAccessor instead.
 */
@Deprecated
public final class ReflectionUtils {

  /** A private constructor for this utility class.
   */
  private ReflectionUtils() {
  }

  /** Sets a value of a possible inaccesible field.
   *
   * @param object The object to set the attribute to. It cannot be null.
   *
   * @param attributeName The name of the attribute to change. The attribute
   * must exist in the object class. It cannot be null.
   *
   * @param value The new value for the attribute.
   */
  public static void setAttribute(final Object object, final String
      attributeName, final Object value) {
    try {
      Field field = getField(object.getClass(), attributeName);
      field.setAccessible(true);
      field.set(object, value);
    } catch (RuntimeException e) {
      throw e;
    } catch (Exception e) {
      throw new RuntimeException("Error setting field " + attributeName, e);
    }
  }

  /** Obtains the value of a possible inaccessible field.
   *
   * @param object The object to set the attribute to. It cannot be null.
   *
   * @param attributeName The name of the attribute to change. The attribute
   * must exist in the object class. It cannot be null.
   *
   * @return The value for the attribute.
   */
  public static Object getAttribute(final Object object, final String
      attributeName) {
    try {
      Field field = getField(object.getClass(), attributeName);
      field.setAccessible(true);
      return field.get(object);
    } catch (RuntimeException e) {
      throw e;
    } catch (Exception e) {
      throw new RuntimeException("Error setting field " + attributeName, e);
    }
  }

  /** Obtains a field from a class, searching the full class hierarchy.
   *
   * @param theClass The class to obtain the attribute from. It cannot be null.
   *
   * @param attributeName The name of the attribute to search. It cannot be
   * null.
   *
   * @return the requested field, never null.
   *
   * @throws NoSuchFieldException if the field was not found.
   */
  @SuppressWarnings("unchecked")
  private static Field getField(final Class<?> theClass, final String
      attributeName) throws NoSuchFieldException {
    try {
      return theClass.getDeclaredField(attributeName);
    } catch (NoSuchFieldException e) {
      Class superclass = theClass.getSuperclass();
      if (superclass != null) {
        return getField(superclass, attributeName);
      } else {
        throw e;
      }
    }
  }
}