Coverage Report

Coverage Report - org.apache.commons.configuration.Configuration

Classes in this File
 /*
  * 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.commons.configuration;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Properties;
 
 /**
  * <p>The main Configuration interface.</p>
  * <p>This interface allows accessing and manipulating a configuration object.
  * The major part of the methods defined in this interface deals with accessing
  * properties of various data types. There is a generic {@code getProperty()}
  * method, which returns the value of the queried property in its raw data
  * type. Other getter methods try to convert this raw data type into a specific
  * data type. If this fails, a {@code ConversionException} will be thrown.</p>
  * <p>For most of the property getter methods an overloaded version exists that
  * allows to specify a default value, which will be returned if the queried
  * property cannot be found in the configuration. The behavior of the methods
  * that do not take a default value in case of a missing property is not defined
  * by this interface and depends on a concrete implementation. E.g. the
  * {@link AbstractConfiguration} class, which is the base class
  * of most configuration implementations provided by this package, per default
  * returns <b>null</b> if a property is not found, but provides the
  * {@link AbstractConfiguration#setThrowExceptionOnMissing(boolean)
  * setThrowExceptionOnMissing()}
  * method, with which it can be configured to throw a {@code NoSuchElementException}
  * exception in that case. (Note that getter methods for primitive types in
  * {@code AbstractConfiguration} always throw an exception for missing
  * properties because there is no way of overloading the return value.)</p>
  * <p>With the {@code addProperty()} and {@code setProperty()} methods
  * new properties can be added to a configuration or the values of properties
  * can be changed. With {@code clearProperty()} a property can be removed.
  * Other methods allow to iterate over the contained properties or to create
  * a subset configuration.</p>
  *
  * @author Commons Configuration team
  * @version $Id: Configuration.java 1204078 2011-11-19 21:28:49Z oheger $
  */
 public interface Configuration
 {
     /**
      * Return a decorator Configuration containing every key from the current
      * Configuration that starts with the specified prefix. The prefix is
      * removed from the keys in the subset. For example, if the configuration
      * contains the following properties:
      *
      * <pre>
      *    prefix.number = 1
      *    prefix.string = Apache
      *    prefixed.foo = bar
      *    prefix = Jakarta</pre>
      *
      * the Configuration returned by {@code subset("prefix")} will contain
      * the properties:
      *
      * <pre>
      *    number = 1
      *    string = Apache
      *    = Jakarta</pre>
      *
      * (The key for the value "Jakarta" is an empty string)
      * <p>
      * Since the subset is a decorator and not a modified copy of the initial
      * Configuration, any change made to the subset is available to the
      * Configuration, and reciprocally.
      *
      * @param prefix The prefix used to select the properties.
      * @return a subset configuration
      *
      * @see SubsetConfiguration
      */
     Configuration subset(String prefix);
 
     /**
      * Check if the configuration is empty.
      *
      * @return {@code true} if the configuration contains no property,
      *         {@code false} otherwise.
      */
     boolean isEmpty();
 
     /**
      * Check if the configuration contains the specified key.
      *
      * @param key the key whose presence in this configuration is to be tested
      *
      * @return {@code true} if the configuration contains a value for this
      *         key, {@code false} otherwise
      */
     boolean containsKey(String key);
 
     /**
      * Add a property to the configuration. If it already exists then the value
      * stated here will be added to the configuration entry. For example, if
      * the property:
      *
      * <pre>resource.loader = file</pre>
      *
      * is already present in the configuration and you call
      *
      * <pre>addProperty("resource.loader", "classpath")</pre>
      *
      * Then you will end up with a List like the following:
      *
      * <pre>["file", "classpath"]</pre>
      *
      * @param key The key to add the property to.
      * @param value The value to add.
      */
     void addProperty(String key, Object value);
 
     /**
      * Set a property, this will replace any previously set values. Set values
      * is implicitly a call to clearProperty(key), addProperty(key, value).
      *
      * @param key The key of the property to change
      * @param value The new value
      */
     void setProperty(String key, Object value);
 
     /**
      * Remove a property from the configuration.
      *
      * @param key the key to remove along with corresponding value.
      */
     void clearProperty(String key);
 
     /**
      * Remove all properties from the configuration.
      */
     void clear();
 
     /**
      * Gets a property from the configuration. This is the most basic get
      * method for retrieving values of properties. In a typical implementation
      * of the {@code Configuration} interface the other get methods (that
      * return specific data types) will internally make use of this method. On
      * this level variable substitution is not yet performed. The returned
      * object is an internal representation of the property value for the passed
      * in key. It is owned by the {@code Configuration} object. So a caller
      * should not modify this object. It cannot be guaranteed that this object
      * will stay constant over time (i.e. further update operations on the
      * configuration may change its internal state).
      *
      * @param key property to retrieve
      * @return the value to which this configuration maps the specified key, or
      *         null if the configuration contains no mapping for this key.
      */
     Object getProperty(String key);
 
     /**
      * Get the list of the keys contained in the configuration that match the
      * specified prefix. For instance, if the configuration contains the
      * following keys:<br>
      * {@code db.user, db.pwd, db.url, window.xpos, window.ypos},<br>
      * an invocation of {@code getKeys("db");}<br>
      * will return the keys below:<br>
      * {@code db.user, db.pwd, db.url}.<br>
      * Note that the prefix itself is included in the result set if there is a
      * matching key. The exact behavior - how the prefix is actually
      * interpreted - depends on a concrete implementation.
      *
      * @param prefix The prefix to test against.
      * @return An Iterator of keys that match the prefix.
      * @see #getKeys()
      */
     Iterator<String> getKeys(String prefix);
 
     /**
      * Get the list of the keys contained in the configuration. The returned
      * iterator can be used to obtain all defined keys. Note that the exact
      * behavior of the iterator's {@code remove()} method is specific to
      * a concrete implementation. It <em>may</em> remove the corresponding
      * property from the configuration, but this is not guaranteed. In any case
      * it is no replacement for calling
      * {@link #clearProperty(String)} for this property. So it is
      * highly recommended to avoid using the iterator's {@code remove()}
      * method.
      *
      * @return An Iterator.
      */
     Iterator<String> getKeys();
 
     /**
      * Get a list of properties associated with the given configuration key.
      * This method expects the given key to have an arbitrary number of String
      * values, each of which is of the form {code key=value}. These
      * strings are split at the equals sign, and the key parts will become
      * keys of the returned {@code Properties} object, the value parts
      * become values.
      *
      * @param key The configuration key.
      * @return The associated properties if key is found.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a String/List.
      *
      * @throws IllegalArgumentException if one of the tokens is
      *         malformed (does not contain an equals sign).
      */
     Properties getProperties(String key);
 
     /**
      * Get a boolean associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated boolean.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Boolean.
      */
     boolean getBoolean(String key);
 
     /**
      * Get a boolean associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated boolean.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Boolean.
      */
     boolean getBoolean(String key, boolean defaultValue);
 
     /**
      * Get a {@link Boolean} associated with the given configuration key.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated boolean if key is found and has valid
      *         format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Boolean.
      */
     Boolean getBoolean(String key, Boolean defaultValue);
 
     /**
      * Get a byte associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated byte.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Byte.
      */
     byte getByte(String key);
 
     /**
      * Get a byte associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated byte.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Byte.
      */
     byte getByte(String key, byte defaultValue);
 
     /**
      * Get a {@link Byte} associated with the given configuration key.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated byte if key is found and has valid format, default
      *         value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an object that
      *         is not a Byte.
      */
     Byte getByte(String key, Byte defaultValue);
 
     /**
      * Get a double associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated double.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Double.
      */
     double getDouble(String key);
 
     /**
      * Get a double associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated double.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Double.
      */
     double getDouble(String key, double defaultValue);
 
     /**
      * Get a {@link Double} associated with the given configuration key.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated double if key is found and has valid
      *         format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Double.
      */
     Double getDouble(String key, Double defaultValue);
 
     /**
      * Get a float associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated float.
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Float.
      */
     float getFloat(String key);
 
     /**
      * Get a float associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated float.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Float.
      */
     float getFloat(String key, float defaultValue);
 
     /**
      * Get a {@link Float} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated float if key is found and has valid
      *         format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Float.
      */
     Float getFloat(String key, Float defaultValue);
 
     /**
      * Get a int associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated int.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Integer.
      */
     int getInt(String key);
 
     /**
      * Get a int associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated int.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Integer.
      */
     int getInt(String key, int defaultValue);
 
     /**
      * Get an {@link Integer} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated int if key is found and has valid format, default
      *         value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an object that
      *         is not a Integer.
      */
     Integer getInteger(String key, Integer defaultValue);
 
     /**
      * Get a long associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated long.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Long.
      */
     long getLong(String key);
 
     /**
      * Get a long associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated long.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Long.
      */
     long getLong(String key, long defaultValue);
 
     /**
      * Get a {@link Long} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated long if key is found and has valid
      * format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Long.
      */
     Long getLong(String key, Long defaultValue);
 
     /**
      * Get a short associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated short.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Short.
      */
     short getShort(String key);
 
     /**
      * Get a short associated with the given configuration key.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated short.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Short.
      */
     short getShort(String key, short defaultValue);
 
     /**
      * Get a {@link Short} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated short if key is found and has valid
      *         format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a Short.
      */
     Short getShort(String key, Short defaultValue);
 
     /**
      * Get a {@link BigDecimal} associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated BigDecimal if key is found and has valid format
      */
     BigDecimal getBigDecimal(String key);
 
     /**
      * Get a {@link BigDecimal} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key          The configuration key.
      * @param defaultValue The default value.
      *
      * @return The associated BigDecimal if key is found and has valid
      *         format, default value otherwise.
      */
     BigDecimal getBigDecimal(String key, BigDecimal defaultValue);
 
     /**
      * Get a {@link BigInteger} associated with the given configuration key.
      *
      * @param key The configuration key.
      *
      * @return The associated BigInteger if key is found and has valid format
      */
     BigInteger getBigInteger(String key);
 
     /**
      * Get a {@link BigInteger} associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key          The configuration key.
      * @param defaultValue The default value.
      *
      * @return The associated BigInteger if key is found and has valid
      *         format, default value otherwise.
      */
     BigInteger getBigInteger(String key, BigInteger defaultValue);
 
     /**
      * Get a string associated with the given configuration key.
      *
      * @param key The configuration key.
      * @return The associated string.
      *
      * @throws ConversionException is thrown if the key maps to an object that
      *         is not a String.
      */
     String getString(String key);
 
     /**
      * Get a string associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated string if key is found and has valid
      *         format, default value otherwise.
      *
      * @throws ConversionException is thrown if the key maps to an object that
      *         is not a String.
      */
     String getString(String key, String defaultValue);
 
     /**
      * Get an array of strings associated with the given configuration key.
      * If the key doesn't map to an existing object an empty array is returned
      *
      * @param key The configuration key.
      * @return The associated string array if key is found.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a String/List of Strings.
      */
     String[] getStringArray(String key);
 
     /**
      * Get a List of strings associated with the given configuration key.
      * If the key doesn't map to an existing object an empty List is returned.
      *
      * @param key The configuration key.
      * @return The associated List.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a List.
      */
     List<Object> getList(String key);
 
     /**
      * Get a List of strings associated with the given configuration key.
      * If the key doesn't map to an existing object, the default value
      * is returned.
      *
      * @param key The configuration key.
      * @param defaultValue The default value.
      * @return The associated List of strings.
      *
      * @throws ConversionException is thrown if the key maps to an
      *         object that is not a List.
      */
     List<Object> getList(String key, List<Object> defaultValue);
 }