SandboxUberspectImpl.java

/**
* Copyright 2016 Nabarun Mondal
* 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 com.noga.njexl.lang.introspection;

import com.noga.njexl.lang.JexlInfo;
import com.noga.njexl.lang.internal.logging.Log;

/**
 * An uberspect that controls usage of properties, methods and contructors through a sandbox.
 * @since 2.1
 */
public class SandboxUberspectImpl extends UberspectImpl {
    /**  The sandbox. */
    protected final Sandbox sandbox;

    /**
     * A constructor for Sandbox uberspect.
     * @param runtimeLogger the logger to use or null to use default
     * @param theSandbox the sandbox instance to use
     */
    public SandboxUberspectImpl(Log runtimeLogger, Sandbox theSandbox) {
        super(runtimeLogger);
        if (theSandbox == null) {
            throw new NullPointerException("sandbox can not be null");
        }
        this.sandbox = theSandbox;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setLoader(ClassLoader cloader) {
        base().setLoader(cloader);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public JexlMethod getConstructorMethod(Object ctorHandle, Object[] args, JexlInfo info) {
        final String className;
        if (ctorHandle instanceof Class<?>) {
            Class<?> clazz = (Class<?>) ctorHandle;
            className = clazz.getName();
        } else if (ctorHandle != null) {
            className = ctorHandle.toString();
        } else {
            return null;
        }
        if (sandbox.execute(className, "") != null) {
            return super.getConstructorMethod(className, args, info);
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public JexlMethod getMethod(Object obj, String method, Object[] args, JexlInfo info) {
        if (obj != null && method != null) {
            String actual = sandbox.execute(obj.getClass().getName(), method);
            if (actual != null) {
                return getMethodExecutor(obj, actual, args);
            }
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public JexlPropertyGet getPropertyGet(Object obj, Object identifier, JexlInfo info) {
        if (obj != null && identifier != null) {
            String actual = sandbox.read(obj.getClass().getName(), identifier.toString());
            if (actual != null) {
                return super.getPropertyGet(obj, actual, info);
            }
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public JexlPropertySet getPropertySet(final Object obj, final Object identifier, Object arg, JexlInfo info) {
        if (obj != null && identifier != null) {
            String actual = sandbox.write(obj.getClass().getName(), identifier.toString());
            if (actual != null) {
                return super.getPropertySet(obj, actual, arg, info);
            }
        }
        return null;

    }
}