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Diffstat (limited to 'trunk/qpid/java/common/src/main/java/org/apache/qpid/util/PropertiesUtils.java')
| -rw-r--r-- | trunk/qpid/java/common/src/main/java/org/apache/qpid/util/PropertiesUtils.java | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/trunk/qpid/java/common/src/main/java/org/apache/qpid/util/PropertiesUtils.java b/trunk/qpid/java/common/src/main/java/org/apache/qpid/util/PropertiesUtils.java new file mode 100644 index 0000000000..d90e3b1a17 --- /dev/null +++ b/trunk/qpid/java/common/src/main/java/org/apache/qpid/util/PropertiesUtils.java @@ -0,0 +1,200 @@ +/* + * + * 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.qpid.util; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.File; +import java.io.FileInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.net.URL; +import java.util.Iterator; +import java.util.Properties; + +/** + * PropertiesHelper defines some static methods which are useful when working with properties + * files. + * + * <p><table id="crc"><caption>CRC Card</caption> + * <tr><th> Responsibilities <th> Collaborations + * <tr><td> Read properties from an input stream + * <tr><td> Read properties from a file + * <tr><td> Read properties from a URL + * <tr><td> Read properties given a path to a file + * <tr><td> Trim any whitespace from property values + * </table> + */ +public class PropertiesUtils +{ + /** Used for logging. */ + private static final Logger log = LoggerFactory.getLogger(PropertiesUtils.class); + + /** + * Get properties from an input stream. + * + * @param is The input stream. + * + * @return The properties loaded from the input stream. + * + * @throws IOException If the is an I/O error reading from the stream. + */ + public static Properties getProperties(InputStream is) throws IOException + { + log.debug("getProperties(InputStream): called"); + + // Create properties object laoded from input stream + Properties properties = new Properties(); + + properties.load(is); + + return properties; + } + + /** + * Get properties from a file. + * + * @param file The file. + * + * @return The properties loaded from the file. + * + * @throws IOException If there is an I/O error reading from the file. + */ + public static Properties getProperties(File file) throws IOException + { + log.debug("getProperties(File): called"); + + // Open the file as an input stream + InputStream is = new FileInputStream(file); + + // Create properties object loaded from the stream + Properties properties = getProperties(is); + + // Close the file + is.close(); + + return properties; + } + + /** + * Get properties from a url. + * + * @param url The URL. + * + * @return The properties loaded from the url. + * + * @throws IOException If there is an I/O error reading from the URL. + */ + public static Properties getProperties(URL url) throws IOException + { + log.debug("getProperties(URL): called"); + + // Open the URL as an input stream + InputStream is = url.openStream(); + + // Create properties object loaded from the stream + Properties properties = getProperties(is); + + // Close the url + is.close(); + + return properties; + } + + /** + * Get properties from a path name. The path name may refer to either a file or a URL. + * + * @param pathname The path name. + * + * @return The properties loaded from the file or URL. + * + * @throws IOException If there is an I/O error reading from the URL or file named by the path. + */ + public static Properties getProperties(String pathname) throws IOException + { + log.debug("getProperties(String): called"); + + // Check that the path is not null + if (pathname == null) + { + return null; + } + + // Check if the path is a URL + if (isURL(pathname)) + { + // The path is a URL + return getProperties(new URL(pathname)); + } + else + { + // Assume the path is a file name + return getProperties(new File(pathname)); + } + } + + /** + * Trims whitespace from property values. This method returns a new set of properties + * the same as the properties specified as an argument but with any white space removed by + * the {@link java.lang.String#trim} method. + * + * @param properties The properties to trim whitespace from. + * + * @return The white space trimmed properties. + */ + public static Properties trim(Properties properties) + { + Properties trimmedProperties = new Properties(); + + // Loop over all the properties + for (Iterator i = properties.keySet().iterator(); i.hasNext();) + { + String next = (String) i.next(); + String nextValue = properties.getProperty(next); + + // Trim the value if it is not null + if (nextValue != null) + { + nextValue.trim(); + } + + // Store the trimmed value in the trimmed properties + trimmedProperties.setProperty(next, nextValue); + } + + return trimmedProperties; + } + + /** + * Helper method. Guesses whether a string is a URL or not. A String is considered to be a url if it begins with + * http:, ftp:, or uucp:. + * + * @param name The string to test for being a URL. + * + * @return True if the string is a URL and false if not. + */ + private static boolean isURL(String name) + { + return (name.toLowerCase().startsWith("http:") || name.toLowerCase().startsWith("ftp:") + || name.toLowerCase().startsWith("uucp:")); + } +} |