Groovy example source code file (GStringTest.java)

This example Groovy source code file (GStringTest.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

acc_public, blockstatement, classnode, constantexpression, constantexpression, declarationexpression, declarationexpression, expressionstatement, expressionstatement, gstringexpression, hello, variableexpression, variableexpression, world

The Groovy GStringTest.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.classgen;

import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.ast.Parameter;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.ast.stmt.AssertStatement;
import org.codehaus.groovy.ast.stmt.BlockStatement;
import org.codehaus.groovy.ast.stmt.ExpressionStatement;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.InvokerInvocationException;
import org.codehaus.groovy.syntax.Token;

/**
 * @author <a href="mailto:james@coredevelopers.net">James Strachan
 * @version $Revision: 21240 $
 */
public class GStringTest extends TestSupport {

    public void testConstructor() throws Exception {
        ClassNode classNode = new ClassNode("Foo", ACC_PUBLIC, ClassHelper.OBJECT_TYPE);

        //Statement printStatement = createPrintlnStatement(new VariableExpression("str"));

        // simulate "Hello ${user}!"
        GStringExpression compositeStringExpr = new GStringExpression("hello ${user}!");
        compositeStringExpr.addString(new ConstantExpression("Hello "));
        compositeStringExpr.addValue(new VariableExpression("user"));
        compositeStringExpr.addString(new ConstantExpression("!"));
        BlockStatement block = new BlockStatement();
        block.addStatement(
                new ExpressionStatement(
                        new DeclarationExpression(
                                new VariableExpression("user"),
                                Token.newSymbol("=", -1, -1),
                                new ConstantExpression("World"))));
        block.addStatement(
                new ExpressionStatement(
                        new DeclarationExpression(new VariableExpression("str"), Token.newSymbol("=", -1, -1), compositeStringExpr)));
        block.addStatement(
                new ExpressionStatement(
                        new MethodCallExpression(VariableExpression.THIS_EXPRESSION, "println", new VariableExpression("str"))));

        block.addStatement(
                new ExpressionStatement(
                        new DeclarationExpression(
                                new VariableExpression("text"),
                                Token.newSymbol("=", -1, -1),
                                new MethodCallExpression(new VariableExpression("str"), "toString", MethodCallExpression.NO_ARGUMENTS))));

        block.addStatement(
                new AssertStatement(
                        new BooleanExpression(
                                new BinaryExpression(
                                        new VariableExpression("text"),
                                        Token.newSymbol("==", -1, -1),
                                        new ConstantExpression("Hello World!"))),
                        new ConstantExpression("Assertion failed") // TODO FIX if empty, AssertionWriter fails because source text is null
                )
        );
        classNode.addMethod(new MethodNode("stringDemo", ACC_PUBLIC, ClassHelper.VOID_TYPE, Parameter.EMPTY_ARRAY, ClassNode.EMPTY_ARRAY, block));

        Class fooClass = loadClass(classNode);
        assertTrue("Loaded a new class", fooClass != null);

        Object bean = fooClass.newInstance();
        assertTrue("Managed to create bean", bean != null);

        //Object[] array = { new Integer(1234), "abc", "def" };

        try {
            InvokerHelper.invokeMethod(bean, "stringDemo", null);
        }
        catch (InvokerInvocationException e) {
            System.out.println("Caught: " + e.getCause());
            e.getCause().printStackTrace();
            fail("Should not have thrown an exception");
        }
    }
}