    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.jexl3;
    018
    019import org.apache.commons.jexl3.introspection.JexlPropertyGet;
    020import org.apache.commons.jexl3.introspection.JexlPropertySet;
    021
    022/**
    023 * Wraps an Object as a JEXL context and NamespaceResolver.
    024 *
    025 * @param <T> the wrapped object type to use
    026 * @since 3.0
    027 */
    028public class ObjectContext<T> implements JexlContext, JexlContext.NamespaceResolver {
    029
    030    /** The property solving jexl engine. */
    031    private final JexlEngine jexl;
    032
    033    /** The object serving as context provider. */
    034    private final T object;
    035
    036    /**
    037     * Creates a new ObjectContext.
    038     *
    039     * @param engine  the jexl engine to use to solve properties
    040     * @param wrapped the object to wrap in this context
    041     */
    042    public ObjectContext(final JexlEngine engine, final T wrapped) {
    043        this.jexl = engine;
    044        this.object = wrapped;
    045    }
    046
    047    @Override
    048    public Object get(final String name) {
    049        final JexlPropertyGet jget = jexl.getUberspect().getPropertyGet(object, name);
    050        if (jget != null) {
    051            try {
    052                return jget.invoke(object);
    053            } catch (final Exception xany) {
    054                if (jexl.isStrict()) {
    055                    throw new JexlException.Property(null, name, true, xany);
    056                }
    057            }
    058        }
    059        return null;
    060    }
    061
    062    /**
    063     * @return the Jexl engine
    064     */
    065    protected JexlEngine getJexl() {
    066        return jexl;
    067    }
    068
    069    /**
    070     * @return the object exposed by this context
    071     */
    072    protected T getObject() {
    073        return object;
    074    }
    075
    076    @Override
    077    public boolean has(final String name) {
    078        return jexl.getUberspect().getPropertyGet(object, name) != null;
    079    }
    080
    081    @Override
    082    public Object resolveNamespace(final String name) {
    083        if (name == null || name.isEmpty()) {
    084            return object;
    085        }
    086        return null;
    087    }
    088
    089    @Override
    090    public void set(final String name, final Object value) {
    091        final JexlPropertySet jset = jexl.getUberspect().getPropertySet(object, name, value);
    092        if (jset != null) {
    093            try {
    094                jset.invoke(object, value);
    095            } catch (final Exception xany) {
    096                // ignore
    097                if (jexl.isStrict()) {
    098                    throw new JexlException.Property(null, name, true, xany);
    099                }
    100            }
    101        }
    102    }
    103}