PackageHelper.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Some helper methods for working with Java packages and versioning.
 *
 * @version 
 */
public final class PackageHelper {
    private static final Logger LOG = LoggerFactory.getLogger(PackageHelper.class);

    private PackageHelper() {
        // Utility Class
    }

    /**
     * Returns true if the version number of the given package name can be found and is greater than or equal to the minimum version.
     *
     * For package names which include multiple dots, dots after the leftmost are removed. So for example a spring version of 2.5.1 
     * is converted to 2.51 so you can assert that it's >= 2.51 (so above 2.50 and less than 2.52 etc).
     *
     * @param packageName the Java package name to compare
     * @param minimumVersion the minimum version number
     * @return true if the package name can be determined and if it's greater than or equal to the minimum value
     */
    public static boolean isValidVersion(String packageName, double minimumVersion) {
        try {
            Package spring = Package.getPackage(packageName);
            if (spring != null) {
                String value = spring.getImplementationVersion();
                if (value != null) {
                    // lets remove any extra dots in the string...
                    int idx = value.indexOf('.');
                    if (idx >= 0) {
                        StringBuilder buffer = new StringBuilder(value.substring(0, ++idx));
                        int i = idx;
                        for (int size = value.length(); i < size; i++) {
                            char ch = value.charAt(i);
                            if (Character.isDigit(ch)) {
                                buffer.append(ch);
                            }
                        }
                        value = buffer.toString();
                    }

                    if (ObjectHelper.isNotEmpty(value)) {
                        double number = Double.parseDouble(value);
                        return number >= minimumVersion;
                    } else {
                        LOG.debug("Could not determine version of package: " + packageName);
                    }
                }
            }
        } catch (Exception e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Could not determine version of package: " + packageName, e);
            }
        }

        return true;
    }
}