content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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.activiti.core.el.juel.util;
  
  import jakarta.el.ELContext;
  import jakarta.el.ELResolver;
  import jakarta.el.PropertyNotFoundException;
  import jakarta.el.PropertyNotWritableException;
  import java.beans.FeatureDescriptor;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  
  /**
   * Simple root property resolver implementation. This resolver handles root properties (i.e.
   * <code>base == null &amp;&amp; property instanceof String</code>), which are stored in a map. The
   * properties can be accessed via the {@link #getProperty(String)},
   * {@link #setProperty(String, Object)}, {@link #isProperty(String)} and {@link #properties()}
   * methods.
   *
   * @author Christoph Beck
   */
  public class RootPropertyResolver extends ELResolver {
  
      private final Map<String, Object> map = Collections.synchronizedMap(new HashMap<String, Object>());
      private final boolean readOnly;
  
      /**
       * Create a read/write root property resolver
       */
      public RootPropertyResolver() {
          this(false);
      }
  
      /**
       * Create a root property resolver
       *
       * @param readOnly
       */
      public RootPropertyResolver(boolean readOnly) {
          this.readOnly = readOnly;
      }
  
      private boolean isResolvable(Object base) {
          return base == null;
      }
  
      private boolean resolve(ELContext context, Object base, Object property) {
          context.setPropertyResolved(isResolvable(base) && property instanceof String);
          return context.isPropertyResolved();
      }
  
      @Override
      public Class<?> getCommonPropertyType(ELContext context, Object base) {
          return isResolvable(context) ? String.class : null;
      }
  
      @Override
      public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) {
          return null;
      }
  
      @Override
      public Class<?> getType(ELContext context, Object base, Object property) {
          return resolve(context, base, property) ? Object.class : null;
      }
  
      @Override
      public Object getValue(ELContext context, Object base, Object property) {
          if (resolve(context, base, property)) {
              if (!isProperty((String) property)) {
                  throw new PropertyNotFoundException("Cannot find property " + property);
              }
              return getProperty((String) property);
          }
          return null;
      }
  
      @Override
      public boolean isReadOnly(ELContext context, Object base, Object property) {
          return resolve(context, base, property) ? readOnly : false;
      }
  
      @Override
      public void setValue(ELContext context, Object base, Object property, Object value)
          throws PropertyNotWritableException {
          if (resolve(context, base, property)) {
              if (readOnly) {
                  throw new PropertyNotWritableException("Resolver is read only!");
              }
              setProperty((String) property, value);
          }
      }
  
      @Override
      public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params) {
          if (resolve(context, base, method)) {
              throw new NullPointerException("Cannot invoke method " + method + " on null");
          }
          return null;
      }
  
      /**
       * Get property value
       *
       * @param property
       *            property name
       * @return value associated with the given property
       */
      public Object getProperty(String property) {
          return map.get(property);
      }
  
      /**
       * Set property value
       *
       * @param property
       *            property name
       * @param value
       *            property value
       */
      public void setProperty(String property, Object value) {
          map.put(property, value);
      }
  
      /**
       * Test property
       *
       * @param property
       *            property name
       * @return <code>true</code> if the given property is associated with a value
       */
      public boolean isProperty(String property) {
          return map.containsKey(property);
      }
  
      /**
       * Get properties
       *
       * @return all property names (in no particular order)
       */
      public Iterable<String> properties() {
          return map.keySet();
      }
  }
  