Groovy example source code file (PluginDefaultGroovyMethods.java)

This example Groovy source code file (PluginDefaultGroovyMethods.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

binding, binding, defaultgroovymethodssupport, io, object, object, plugindefaultgroovymethods, reader, reader, scriptexception, scriptexception, string, suppresswarnings, util

The Groovy PluginDefaultGroovyMethods.java source code

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * 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.codehaus.groovy.vmplugin.v6;

import groovy.lang.Binding;
import org.codehaus.groovy.runtime.DefaultGroovyMethodsSupport;

import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
import java.io.Reader;
import java.util.Map;
import java.util.Set;

/**
 * This class defines new Java 6 specific groovy methods which extend the normal
 * JDK classes inside the Groovy environment. Static methods are used with the
 * first parameter the destination class.
 */
public class PluginDefaultGroovyMethods extends DefaultGroovyMethodsSupport {
    /**
     * Executes the specified script.  The default <code>ScriptContext for the ScriptEngine
     * is used. Variables from a Groovy <code>Binding are made available in the default scope of the
     * <code>Bindings of the ScriptEngine. Resulting variables in the Bindings
     * are returned back to the Groovy <code>Binding.
     *
     * @param self A ScriptEngine
     * @param script The script language source to be executed
     * @param binding A Groovy binding
     * @return The value returned from the execution of the script (if supported by the Script engine)
     * @throws javax.script.ScriptException if error occurs in script
     * @throws NullPointerException if the argument is null
     * @see #eval(javax.script.ScriptEngine, java.io.Reader, groovy.lang.Binding)
     * @since 1.7.3
     */
    public static Object eval(ScriptEngine self, String script, Binding binding) throws ScriptException {
        storeBindingVars(self, binding);
        Object result = self.eval(script);
        retrieveBindingVars(self, binding);
        return result;
    }

    /**
     * Same as <code>eval(ScriptEngine, Reader, Binding) except that the
     * source of the script is provided as a <code>Reader
     *
     * @param self A ScriptEngine
     * @param reader The source of the script
     * @param binding A Groovy binding
     * @return The value returned by the script
     * @throws javax.script.ScriptException if an error occurs in script
     * @throws NullPointerException if the argument is null
     * @see #eval(javax.script.ScriptEngine, java.lang.String, groovy.lang.Binding)
     * @since 1.7.3
     */
    public static Object eval(ScriptEngine self, Reader reader, Binding binding) throws ScriptException {
        storeBindingVars(self, binding);
        Object result = self.eval(reader);
        retrieveBindingVars(self, binding);
        return result;
    }

    private static void retrieveBindingVars(ScriptEngine self, Binding binding) {
        Set<Map.Entry returnVars = self.getBindings(ScriptContext.ENGINE_SCOPE).entrySet();
        for (Map.Entry<String, Object> me : returnVars) {
            binding.setVariable(me.getKey(), me.getValue());
        }
    }

    @SuppressWarnings("unchecked")
    private static void storeBindingVars(ScriptEngine self, Binding binding) {
        Set<Map.Entry> vars = binding.getVariables().entrySet();
        for (Map.Entry me : vars) {
            self.put(me.getKey().toString(), me.getValue());
        }
    }

}