001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.discovery.tools; 018 019 import java.util.Properties; 020 021 import org.apache.commons.discovery.resource.ClassLoaders; 022 023 024 /** 025 * Holder for a default class. 026 * 027 * Class may be specified by name (String) or class (Class). 028 * Using the holder complicates the users job, but minimized # of API's. 029 * 030 * @author Richard A. Sitze 031 */ 032 public class PropertiesHolder { 033 private Properties properties; 034 private final String propertiesFileName; 035 036 public PropertiesHolder(Properties properties) { 037 this.properties = properties; 038 this.propertiesFileName = null; 039 } 040 041 public PropertiesHolder(String propertiesFileName) { 042 this.properties = null; 043 this.propertiesFileName = propertiesFileName; 044 } 045 046 /** 047 * @param spi Optional SPI (may be null). 048 * If provided, an attempt is made to load the 049 * property file as-per Class.getResource(). 050 * 051 * @param loaders Used only if properties need to be loaded. 052 * 053 * @return Properties. Load the properties if necessary. 054 */ 055 public Properties getProperties(SPInterface spi, ClassLoaders loaders) { 056 if (properties == null) { 057 properties = ResourceUtils.loadProperties(spi.getSPClass(), getPropertiesFileName(), loaders); 058 } 059 return properties; 060 } 061 062 public String getPropertiesFileName() { 063 return propertiesFileName; 064 } 065 }