com.jkoolcloud.tnt4j.streams.transform.JavaScriptTransformation.java Source code

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Here is the source code for com.jkoolcloud.tnt4j.streams.transform.JavaScriptTransformation.java

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/*
 * Copyright 2014-2018 JKOOL, LLC.
 *
 * 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.jkoolcloud.tnt4j.streams.transform;

import javax.script.Bindings;
import javax.script.CompiledScript;
import javax.script.ScriptException;
import javax.script.SimpleBindings;

import org.apache.commons.collections4.CollectionUtils;

import com.jkoolcloud.tnt4j.core.Property;
import com.jkoolcloud.tnt4j.sink.DefaultEventSinkFactory;
import com.jkoolcloud.tnt4j.sink.EventSink;
import com.jkoolcloud.tnt4j.streams.fields.ActivityInfo;
import com.jkoolcloud.tnt4j.streams.utils.StreamsResources;
import com.jkoolcloud.tnt4j.streams.utils.StreamsScriptingUtils;

/**
 * Data value transformation based on JavaScript code/expressions.
 * 
 * @version $Revision: 2 $
 *
 * @see com.jkoolcloud.tnt4j.streams.utils.StreamsScriptingUtils#compileJSScript(String)
 * @see javax.script.CompiledScript#eval(javax.script.Bindings)
 */
public class JavaScriptTransformation extends AbstractScriptTransformation<Object> {
    private static final EventSink LOGGER = DefaultEventSinkFactory
            .defaultEventSink(JavaScriptTransformation.class);

    private CompiledScript script;

    /**
     * Constructs a new JavaScriptTransformation.
     *
     * @param name
     *            transformation name
     * @param scriptCode
     *            transformation script code
     */
    public JavaScriptTransformation(String name, String scriptCode) {
        super(name, scriptCode);
    }

    /**
     * Constructs a new JavaScriptTransformation.
     *
     * @param name
     *            transformation name
     * @param scriptCode
     *            transformation script code
     * @param phase
     *            activity data value resolution phase
     */
    public JavaScriptTransformation(String name, String scriptCode, Phase phase) {
        super(name, scriptCode, phase);
    }

    @Override
    protected EventSink getLogger() {
        return LOGGER;
    }

    @Override
    protected String getHandledLanguage() {
        return StreamsScriptingUtils.JAVA_SCRIPT_LANG;
    }

    @Override
    protected void initTransformation() {
        super.initTransformation();

        try {
            script = StreamsScriptingUtils.compileJSScript(getExpression());
        } catch (ScriptException exc) {
            throw new IllegalArgumentException(
                    StreamsResources.getStringFormatted(StreamsResources.RESOURCE_BUNDLE_NAME,
                            "ScriptTransformation.invalid.script", getName(), getScriptCode()),
                    exc);
        }
    }

    @Override
    public Object transform(Object value, ActivityInfo ai) throws TransformationException {
        Bindings bindings = new SimpleBindings();
        bindings.put(StreamsScriptingUtils.FIELD_VALUE_VARIABLE_EXPR, value);

        if (ai != null && CollectionUtils.isNotEmpty(exprVars)) {
            for (String eVar : exprVars) {
                Property eKV = resolveFieldKeyAndValue(eVar, ai);

                bindings.put(eKV.getKey(), eKV.getValue());
            }
        }

        try {
            Object tValue = script.eval(bindings);

            logEvaluationResult(bindings, tValue);

            return tValue;
        } catch (Exception exc) {
            throw new TransformationException(
                    StreamsResources.getStringFormatted(StreamsResources.RESOURCE_BUNDLE_NAME,
                            "ValueTransformation.transformation.failed", getName(), getPhase()),
                    exc);
        }
    }
}