ScriptDemo.java

/*
 * Janino - An embedded Java[TM] compiler
 *
 * Copyright (c) 2001-2010 Arno Unkrig. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
 *       following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 *       following disclaimer in the documentation and/or other materials provided with the distribution.
 *    3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
 *       products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.codehaus.commons.compiler.samples;

import java.util.Arrays;

import org.codehaus.commons.compiler.CompilerFactoryFactory;
import org.codehaus.commons.compiler.IScriptEvaluator;

/**
 * A test program that allows you to play around with the {@link IScriptEvaluator} class.
 */
public final
class ScriptDemo extends DemoBase {

    /***/
    public static void
    main(String[] args) throws Exception {

        Class<?>   returnType       = void.class;
        String[]   parameterNames   = {};
        Class<?>[] parameterTypes   = {};
        Class<?>[] thrownExceptions = {};
        String[]   defaultImports   = {};

        int i;
        for (i = 0; i < args.length; ++i) {
            String arg = args[i];
            if (!arg.startsWith("-")) break;
            if ("-rt".equals(arg)) {
                returnType = DemoBase.stringToType(args[++i]);
            } else
            if ("-pn".equals(arg)) {
                parameterNames = DemoBase.explode(args[++i]);
            } else
            if ("-pt".equals(arg)) {
                parameterTypes = DemoBase.stringToTypes(args[++i]);
            } else
            if ("-te".equals(arg)) {
                thrownExceptions = DemoBase.stringToTypes(args[++i]);
            } else
            if ("-di".equals(arg)) {
                defaultImports = DemoBase.explode(args[++i]);
            } else
           if ("-help".equals(arg)) {
               System.err.println("Usage:");
               System.err.println("  ScriptDemo { <option> } <script> { <parameter-value> }");
               System.err.println("Valid options are");
               System.err.println(" -rt <return-type>                            (default: void)");
               System.err.println(" -pn <comma-separated-parameter-names>        (default: none)");
               System.err.println(" -pt <comma-separated-parameter-types>        (default: none)");
               System.err.println(" -te <comma-separated-thrown-exception-types> (default: none)");
               System.err.println(" -di <comma-separated-default-imports>        (default: none)");
               System.err.println(" -help");
               System.err.println("The number of parameter names, types and values must be identical.");
               System.exit(0);
           } else
           {
               System.err.println("Invalid command line option \"" + arg + "\"; try \"-help\".");
               System.exit(1);
           }
        }

        if (i == args.length) {
            System.err.println("Script missing on command line; try \"-help\".");
            System.exit(1);
        }
        final String script = args[i++];

        if (parameterTypes.length != parameterNames.length) {
            System.err.println("Parameter type count and parameter name count do not match; try \"-help\".");
            System.exit(1);
        }

        // One command line argument for each parameter.
        if (args.length - i != parameterNames.length) {
            System.err.println("Argument and parameter count do not match; try \"-help\".");
            System.exit(1);
        }

        // Convert command line arguments to call arguments.
        Object[] arguments = new Object[parameterNames.length];
        for (int j = 0; j < parameterNames.length; ++j) {
            arguments[j] = DemoBase.createObject(parameterTypes[j], args[i + j]);
        }

        // Create "ScriptEvaluator" object.
        IScriptEvaluator se = (
            CompilerFactoryFactory
            .getDefaultCompilerFactory(ScriptDemo.class.getClassLoader())
            .newScriptEvaluator()
        );
        se.setReturnType(returnType);
        se.setDefaultImports(defaultImports);
        se.setParameters(parameterNames, parameterTypes);
        se.setThrownExceptions(thrownExceptions);
        se.cook(script);

        // Evaluate script with actual parameter values.
        Object res = se.evaluate(arguments);

        // Print script return value.
        System.out.println("Result = " + (
            res instanceof Object[]
            ? Arrays.toString((Object[]) res)
            : String.valueOf(res)
        ));
    }

    private ScriptDemo() {}
}