com.google.gdt.eclipse.designer.smart.parser.ClassLoaderValidator.java Source code

Introduction

Here is the source code for com.google.gdt.eclipse.designer.smart.parser.ClassLoaderValidator.java

Source

/*******************************************************************************
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * 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.google.gdt.eclipse.designer.smart.parser;

import com.google.gdt.eclipse.designer.model.widgets.support.GwtState;
import com.google.gdt.eclipse.designer.parser.IClassLoaderValidator;
import com.google.gdt.eclipse.designer.smart.IExceptionConstants;

import org.eclipse.wb.internal.core.utils.exception.DesignerException;
import org.eclipse.wb.internal.core.utils.execution.ExecutionUtils;
import org.eclipse.wb.internal.core.utils.execution.RunnableObjectEx;
import org.eclipse.wb.internal.core.utils.jdt.core.ProjectUtils;
import org.eclipse.wb.internal.core.utils.reflect.ReflectionUtils;

import org.eclipse.jdt.core.IJavaProject;

import org.apache.commons.lang.ArrayUtils;

/**
 * {@link IClassLoaderValidator} for SmartGWT.
 * 
 * @author scheglov_ke
 * @coverage SmartGWT
 */
public final class ClassLoaderValidator implements IClassLoaderValidator {
    private static final String[] VALID_VERSIONS = { "2.4", "2.5" };
    private static final String VALID_VERSIONS_STRING = "2.4, 2.5";

    ////////////////////////////////////////////////////////////////////////////
    //
    // IClassLoaderValidator
    //
    ////////////////////////////////////////////////////////////////////////////
    public void validate(IJavaProject javaProject, GwtState state) throws Exception {
        if (hasSmartGWT(javaProject, state)) {
            ClassLoader classLoader = state.getClassLoader();
            // version
            {
                String description = getWrongVersionDescription(classLoader);
                if (description != null) {
                    throw new DesignerException(IExceptionConstants.INCORRECT_VERSION, VALID_VERSIONS_STRING,
                            description);
                }
            }
        }
    }

    /**
     * @return <code>true</code> if given {@link GwtState} has access to SmartGWT.
     */
    private static boolean hasSmartGWT(IJavaProject javaProject, GwtState state) {
        if (ProjectUtils.hasType(javaProject, "com.smartgwt.client.widgets.Canvas")) {
            try {
                state.getClassLoader().loadClass("com.smartgwt.client.Version");
                return true;
            } catch (ClassNotFoundException e) {
            }
        }
        return false;
    }

    /**
     * @return the description of invalid version, or <code>null</code> if version in valid.
     */
    private static String getWrongVersionDescription(final ClassLoader classLoader) {
        return ExecutionUtils.runObject(new RunnableObjectEx<String>() {
            public String runObject() throws Exception {
                Class<?> classVersion = classLoader.loadClass("com.smartgwt.client.Version");
                String version = (String) ReflectionUtils.invokeMethod(classVersion, "getVersion()");
                if (ArrayUtils.contains(VALID_VERSIONS, version)) {
                    initializeSmartGWT(classLoader);
                    return null;
                }
                return version;
            }
        }, "See logged exception");
    }

    /**
     * Initialize SmartGWT environment.
     */
    private static void initializeSmartGWT(final ClassLoader classLoader) throws Exception {
        // try process SmartGWT initialization routine
        try {
            // SmartGwtEntryPoint for version 2.3
            Class<?> smartGWTEntryPointClass = classLoader.loadClass("com.smartgwt.client.SmartGwtEntryPoint");
            Object smartGWTEntryPoint = smartGWTEntryPointClass.newInstance();
            ReflectionUtils.invokeMethod2(smartGWTEntryPoint, "onModuleLoad");
        } catch (ClassNotFoundException e) {
            // do nothing
        }
    }
}