1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.discovery.tools; 18 19 import java.util.Properties; 20 21 import org.apache.commons.discovery.resource.ClassLoaders; 22 23 /** 24 * Holder for a default class. 25 * 26 * Class may be specified by name (String) or class (Class). 27 * Using the holder complicates the users job, but minimized # of API's. 28 */ 29 public class PropertiesHolder { 30 31 private Properties properties; 32 33 private final String propertiesFileName; 34 35 /** 36 * Creates a new {@code PropertiesHolder} instance given an 37 * already load {@code Properties} set. 38 * 39 * @param properties The already load {@code Properties} set 40 */ 41 public PropertiesHolder(Properties properties) { 42 this.properties = properties; 43 this.propertiesFileName = null; 44 } 45 46 /** 47 * Creates a new {@code PropertiesHolder} instance given a 48 * property file name. 49 * 50 * @param propertiesFileName The property file name 51 */ 52 public PropertiesHolder(String propertiesFileName) { 53 this.properties = null; 54 this.propertiesFileName = propertiesFileName; 55 } 56 57 /** 58 * Returns the {@code Properties} instance, loaded if necessary from {@code propertiesFileName}. 59 * 60 * @param spi Optional SPI (may be null). 61 * If provided, an attempt is made to load the 62 * property file as-per Class.getResource(). 63 * 64 * @param loaders Used only if properties need to be loaded. 65 * 66 * @return The {@code Properties}, loaded if necessary. 67 */ 68 public Properties getProperties(SPInterface<?> spi, ClassLoaders loaders) { 69 if (properties == null) { 70 properties = ResourceUtils.loadProperties(spi.getSPClass(), getPropertiesFileName(), loaders); 71 } 72 return properties; 73 } 74 75 /** 76 * Returns the property file name 77 * 78 * @return The property file name 79 */ 80 public String getPropertiesFileName() { 81 return propertiesFileName; 82 } 83 84 }