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 */ 017package org.apache.commons.configuration2.builder.combined; 018 019import java.util.Map; 020 021import org.apache.commons.configuration2.ConfigurationUtils; 022import org.apache.commons.configuration2.builder.BasicBuilderParameters; 023import org.apache.commons.configuration2.builder.BuilderParameters; 024 025/** 026 * <p> 027 * A specialized parameters object for {@link MultiFileConfigurationBuilder}. 028 * </p> 029 * <p> 030 * A parameters object of this type is used by a configuration builder with 031 * manages multiple file-based configurations. Such a builder is a bit special 032 * because it does not create a configuration on its own, but delegates to a 033 * file-based builder for this purpose. Therefore, parameters inherited from the 034 * super class are treated differently: 035 * </p> 036 * <ul> 037 * <li>The {@link org.apache.commons.configuration2.interpol.ConfigurationInterpolator 038 * ConfigurationInterpolator} is needed by a 039 * {@code MultiFileConfigurationBuilder} to resolve the file pattern. It is 040 * expected to be set and will not be passed to sub configurations created by 041 * the builder.</li> 042 * <li>All other parameters are evaluated when creating sub configurations. 043 * However, it is preferred to use the 044 * {@link #setManagedBuilderParameters(BuilderParameters)} method to define all 045 * properties of sub configurations in a single place. If such a parameters 046 * object is set, its properties take precedence.</li> 047 * </ul> 048 * <p> 049 * This class is not thread-safe. It is intended that an instance is constructed 050 * and initialized by a single thread during configuration of a 051 * {@code ConfigurationBuilder}. 052 * </p> 053 * 054 * @since 2.0 055 */ 056public class MultiFileBuilderParametersImpl extends BasicBuilderParameters 057 implements MultiFileBuilderProperties<MultiFileBuilderParametersImpl> 058{ 059 /** Constant for the key in the parameters map used by this class. */ 060 private static final String PARAM_KEY = RESERVED_PARAMETER_PREFIX 061 + MultiFileBuilderParametersImpl.class.getName(); 062 063 /** The parameters object for managed builders. */ 064 private BuilderParameters managedBuilderParameters; 065 066 /** The file pattern. */ 067 private String filePattern; 068 069 /** 070 * Obtains an instance of this class from the given map with parameters. If 071 * this map does not contain an instance, result is <b>null</b>. This is 072 * equivalent to {@code fromParameters(params, false)}. 073 * 074 * @param params the map with parameters (must not be <b>null</b>) 075 * @return an instance of this class fetched from the map or <b>null</b> 076 * @throws NullPointerException if the map with parameters is <b>null</b> 077 */ 078 public static MultiFileBuilderParametersImpl fromParameters( 079 final Map<String, Object> params) 080 { 081 return fromParameters(params, false); 082 } 083 084 /** 085 * Obtains an instance of this class from the given map with parameters and 086 * creates a new object if such an instance cannot be found. This method can 087 * be used to obtain an instance from a map which has been created using the 088 * {@code getParameters()} method. If the map does not contain an instance 089 * under the expected key and the {@code createIfMissing} parameter is 090 * <b>true</b>, a new instance is created. Otherwise, result is <b>null</b>. 091 * 092 * @param params the map with parameters (must not be <b>null</b>) 093 * @param createIfMissing a flag whether a new instance should be created if 094 * necessary 095 * @return an instance of this class fetched from the map or <b>null</b> 096 * @throws NullPointerException if the map with parameters is <b>null</b> 097 */ 098 public static MultiFileBuilderParametersImpl fromParameters( 099 final Map<String, Object> params, final boolean createIfMissing) 100 { 101 MultiFileBuilderParametersImpl instance = 102 (MultiFileBuilderParametersImpl) params.get(PARAM_KEY); 103 if (instance == null && createIfMissing) 104 { 105 instance = new MultiFileBuilderParametersImpl(); 106 } 107 return instance; 108 } 109 110 /** 111 * Returns the pattern for determining file names for managed 112 * configurations. 113 * 114 * @return the file pattern 115 */ 116 public String getFilePattern() 117 { 118 return filePattern; 119 } 120 121 @Override 122 public MultiFileBuilderParametersImpl setFilePattern(final String p) 123 { 124 filePattern = p; 125 return this; 126 } 127 128 /** 129 * Returns the parameters object for managed configuration builders. 130 * 131 * @return the parameters for sub configurations 132 */ 133 public BuilderParameters getManagedBuilderParameters() 134 { 135 return managedBuilderParameters; 136 } 137 138 @Override 139 public MultiFileBuilderParametersImpl setManagedBuilderParameters( 140 final BuilderParameters p) 141 { 142 managedBuilderParameters = p; 143 return this; 144 } 145 146 /** 147 * {@inheritDoc} This implementation puts a reference to this object under a 148 * reserved key in the resulting parameters map. 149 */ 150 @Override 151 public Map<String, Object> getParameters() 152 { 153 final Map<String, Object> params = super.getParameters(); 154 params.put(PARAM_KEY, this); 155 return params; 156 } 157 158 /** 159 * {@inheritDoc} This implementation also tries to clone the parameters 160 * object for managed builders if possible. 161 */ 162 @Override 163 public MultiFileBuilderParametersImpl clone() 164 { 165 final MultiFileBuilderParametersImpl copy = 166 (MultiFileBuilderParametersImpl) super.clone(); 167 copy.setManagedBuilderParameters((BuilderParameters) ConfigurationUtils 168 .cloneIfPossible(getManagedBuilderParameters())); 169 return copy; 170 } 171}