Coverage Summary for Class: VariableSelector (org.kitodo.production.metadata.copier)

 /*
  * (c) Kitodo. Key to digital objects e. V. <contact@kitodo.org>
  *
  * This file is part of the Kitodo project.
  *
  * It is licensed under GNU General Public License version 3 or later.
  *
  * For the full copyright and license information, please read the
  * GPL3-License.txt file that was distributed with this source code.
  */
 
 package org.kitodo.production.metadata.copier;
 
 import java.lang.reflect.Field;
 
 import org.kitodo.exceptions.MetadataException;
 
 /**
  * A VariableSelector provides methods to retrieve variables used in the source
  * code.
  */
 public class VariableSelector extends DataSelector {
 
     /**
      * Holds the name of the variable to resolve.
      */
     private final String qualifier;
 
     /**
      * If the selector passed to the constructor references a variable that is
      * part of an object which is held in a variable itself, then this
      * VariableSelector only handles the resolving of the first variable, and
      * the field subselector holds another VariableSelector to resolve the
      * remaining variable. Otherwise, this field is null.
      */
     private final VariableSelector subselector;
 
     /**
      * Creates a new VariableSelector.
      *
      * @param selector
      *            String identifying a variable
      */
     public VariableSelector(String selector) {
         if (selector.startsWith(VARIABLE_REFERENCE)) {
             selector = selector.substring(1);
         }
         String[] a = selector.split("\\.", 2);
         if (a.length == 2) {
             this.qualifier = a[0];
             this.subselector = new VariableSelector(a[1]);
         } else {
             this.qualifier = selector;
             this.subselector = null;
         }
     }
 
     /**
      * Returns the value of the variable named by the path used to construct the
      * variable selector. Returns null if the variable isn’t available.
      *
      * @param data
      *            object to inspect
      * @return value of the variable, or null if not found
      * @see org.kitodo.production.metadata.copier.DataSelector#findIn(CopierData)
      */
     @Override
     public String findIn(CopierData data) {
         return findIn((Object) data);
     }
 
     /**
      * Returns the value of the variable named by the path used to construct the
      * variable selector. Returns null if the variable isn’t available.
      *
      * @param classInstance
      *            object to inspect
      * @return value of the variable, or null if not found
      */
     private String findIn(Object classInstance) {
         try {
             Field classesFieldReference = classInstance.getClass().getDeclaredField(qualifier);
             classesFieldReference.setAccessible(true);
             Object fieldValue = classesFieldReference.get(classInstance);
             if (subselector == null) {
                 return String.valueOf(fieldValue);
             } else {
                 return fieldValue != null ? subselector.findIn(fieldValue) : null;
             }
         } catch (NoSuchFieldException e) {
             return null;
         } catch (IllegalArgumentException | IllegalAccessException e) {
             throw new MetadataException(e.getMessage(), e);
         }
     }
 
     /**
      * Returns a string that textually represents this LocalMetadataSelector.
      *
      * @return a string representation of this LocalMetadataSelector
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString() {
         if (subselector == null) {
             return VARIABLE_REFERENCE + qualifier;
         } else {
             return VARIABLE_REFERENCE + qualifier + '.' + subselector.toString().substring(1);
         }
     }
 }