Class AbstractConfiguration

java.lang.Object
org.apache.commons.configuration.event.EventSource
org.apache.commons.configuration.AbstractConfiguration
All Implemented Interfaces:
Configuration
Direct Known Subclasses:
AppletConfiguration, BaseConfiguration, CompositeConfiguration, DatabaseConfiguration, DataConfiguration, HierarchicalConfiguration, JNDIConfiguration, MapConfiguration, ServletConfiguration, ServletContextConfiguration, ServletFilterConfiguration, ServletRequestConfiguration, SubsetConfiguration
public abstract class AbstractConfiguration extends EventSource implements Configuration

Abstract configuration class. Provides basic functionality but does not store any data.

If you want to write your own Configuration class then you should implement only abstract methods from this class. A lot of functionality needed by typical implementations of the Configuration interface is already provided by this base class. Following is a list of features implemented here:

  • Data conversion support. The various data types required by the Configuration interface are already handled by this base class. A concrete sub class only needs to provide a generic getProperty() method.
  • Support for variable interpolation. Property values containing special variable tokens (like ${var}) will be replaced by their corresponding values.
  • Support for string lists. The values of properties to be added to this configuration are checked whether they contain a list delimiter character. If this is the case and if list splitting is enabled, the string is split and multiple values are added for this property. (With the setListDelimiter() method the delimiter character can be specified; per default a comma is used. The setDelimiterParsingDisabled() method can be used to disable list splitting completely.)
  • Allows to specify how missing properties are treated. Per default the get methods returning an object will return null if the searched property key is not found (and no default value is provided). With the setThrowExceptionOnMissing() method this behavior can be changed to throw an exception when a requested property cannot be found.
  • Basic event support. Whenever this configuration is modified registered event listeners are notified. Refer to the various EVENT_XXX constants to get an impression about which event types are supported.

Version:
$Id: AbstractConfiguration.java 1534064 2013-10-21 08:44:33Z henning $
Author:
Konstantin Shaposhnikov , Henning P. Schmiedehausen

  • Field Details

  • Constructor Details

  • Method Details

    • setDefaultListDelimiter

      public static void setDefaultListDelimiter(char delimiter)
      For configurations extending AbstractConfiguration, allow them to change the listDelimiter from the default comma (","). This value will be used only when creating new configurations. Those already created will not be affected by this change
      Parameters:
      delimiter - The new listDelimiter

    • setDelimiter

      @Deprecated public static void setDelimiter(char delimiter)
      Deprecated.
      Use AbstractConfiguration.setDefaultListDelimiter(char) instead
      Sets the default list delimiter.
      Parameters:
      delimiter - the delimiter character

    • getDefaultListDelimiter

      public static char getDefaultListDelimiter()
      Retrieve the current delimiter. By default this is a comma (",").
      Returns:
      The delimiter in use

    • getDelimiter

      @Deprecated public static char getDelimiter()
      Deprecated.
      Use AbstractConfiguration.getDefaultListDelimiter() instead
      Returns the default list delimiter.
      Returns:
      the default list delimiter

    • setListDelimiter

      public void setListDelimiter(char listDelimiter)
      Change the list delimiter for this configuration. Note: this change will only be effective for new parsings. If you want it to take effect for all loaded properties use the no arg constructor and call this method before setting the source.
      Parameters:
      listDelimiter - The new listDelimiter

    • getListDelimiter

      public char getListDelimiter()
      Retrieve the delimiter for this configuration. The default is the value of defaultListDelimiter.
      Returns:
      The listDelimiter in use

    • isDelimiterParsingDisabled

      public boolean isDelimiterParsingDisabled()
      Determine if this configuration is using delimiters when parsing property values to convert them to lists of values. Defaults to false
      Returns:
      true if delimiters are not being used

    • setDelimiterParsingDisabled

      public void setDelimiterParsingDisabled(boolean delimiterParsingDisabled)
      Set whether this configuration should use delimiters when parsing property values to convert them to lists of values. By default delimiter parsing is enabled Note: this change will only be effective for new parsings. If you want it to take effect for all loaded properties use the no arg constructor and call this method before setting source.
      Parameters:
      delimiterParsingDisabled - a flag whether delimiter parsing should be disabled

    • setThrowExceptionOnMissing

      public void setThrowExceptionOnMissing(boolean throwExceptionOnMissing)
      Allows to set the throwExceptionOnMissing flag. This flag controls the behavior of property getter methods that return objects if the requested property is missing. If the flag is set to false (which is the default value), these methods will return null. If set to true, they will throw a NoSuchElementException exception. Note that getter methods for primitive data types are not affected by this flag.
      Parameters:
      throwExceptionOnMissing - The new value for the property

    • isThrowExceptionOnMissing

      public boolean isThrowExceptionOnMissing()
      Returns true if missing values throw Exceptions.
      Returns:
      true if missing values throw Exceptions

    • getSubstitutor

      public org.apache.commons.lang.text.StrSubstitutor getSubstitutor()
      Returns the object that is responsible for variable interpolation.
      Returns:
      the object responsible for variable interpolation
      Since:
      1.4

    • getInterpolator

      public ConfigurationInterpolator getInterpolator()
      Returns the ConfigurationInterpolator object that manages the lookup objects for resolving variables. Note: If this object is manipulated (e.g. new lookup objects added), synchronization has to be manually ensured. Because ConfigurationInterpolator is not thread-safe concurrent access to properties of this configuration instance (which causes the interpolator to be invoked) may cause race conditions.
      Returns:
      the ConfigurationInterpolator associated with this configuration
      Since:
      1.4

    • createInterpolator

      protected ConfigurationInterpolator createInterpolator()
      Creates the interpolator object that is responsible for variable interpolation. This method is invoked on first access of the interpolation features. It creates a new instance of ConfigurationInterpolator and sets the default lookup object to an implementation that queries this configuration.
      Returns:
      the newly created interpolator object
      Since:
      1.4

    • getLogger

      public org.apache.commons.logging.Log getLogger()
      Returns the logger used by this configuration object.
      Returns:
      the logger
      Since:
      1.4

    • setLogger

      public void setLogger(org.apache.commons.logging.Log log)
      Allows to set the logger to be used by this configuration object. This method makes it possible for clients to exactly control logging behavior. Per default a logger is set that will ignore all log messages. Derived classes that want to enable logging should call this method during their initialization with the logger to be used.
      Parameters:
      log - the new logger
      Since:
      1.4

    • addErrorLogListener

      public void addErrorLogListener()
      Adds a special ConfigurationErrorListener object to this configuration that will log all internal errors. This method is intended to be used by certain derived classes, for which it is known that they can fail on property access (e.g. DatabaseConfiguration).
      Since:
      1.4

    • addProperty

      public void addProperty(String key, Object value)
      Description copied from interface: Configuration
      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: 
      resource.loader = file
      is already present in the configuration and you call 
      addProperty("resource.loader", "classpath")
      Then you will end up with a List like the following: 
      ["file", "classpath"]
      Specified by:
      addProperty in interface Configuration
      Parameters:
      key - The key to add the property to.
      value - The value to add.

    • addPropertyDirect

      protected abstract void addPropertyDirect(String key, Object value)
      Adds a key/value pair to the Configuration. Override this method to provide write access to underlying Configuration store.
      Parameters:
      key - key to use for mapping
      value - object to store

    • interpolate

      protected String interpolate(String base)
      interpolate key names to handle ${key} stuff
      Parameters:
      base - string to interpolate
      Returns:
      returns the key name with the ${key} substituted

    • interpolate

      protected Object interpolate(Object value)
      Returns the interpolated value. Non String values are returned without change.
      Parameters:
      value - the value to interpolate
      Returns:
      returns the value with variables substituted

    • interpolateHelper

      @Deprecated protected String interpolateHelper(String base, List<?> priorVariables)
      Deprecated.
      Interpolation is now handled by PropertyConverter; this method will no longer be called
      Recursive handler for multple levels of interpolation. When called the first time, priorVariables should be null.
      Parameters:
      base - string with the ${key} variables
      priorVariables - serves two purposes: to allow checking for loops, and creating a meaningful exception message should a loop occur. It's 0'th element will be set to the value of base from the first call. All subsequent interpolated variables are added afterward.
      Returns:
      the string with the interpolation taken care of

    • subset

      public Configuration subset(String prefix)
      Description copied from 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: 
         prefix.number = 1
   prefix.string = Apache
   prefixed.foo = bar
   prefix = Jakarta
      the Configuration returned by subset("prefix") will contain the properties: 
         number = 1
   string = Apache
   = Jakarta
      (The key for the value "Jakarta" is an empty string)

      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.

      Specified by:
      subset in interface Configuration
      Parameters:
      prefix - The prefix used to select the properties.
      Returns:
      a subset configuration
      See Also:

    • setProperty

      public void setProperty(String key, Object value)
      Description copied from interface: Configuration
      Set a property, this will replace any previously set values. Set values is implicitly a call to clearProperty(key), addProperty(key, value).
      Specified by:
      setProperty in interface Configuration
      Parameters:
      key - The key of the property to change
      value - The new value

    • clearProperty

      public void clearProperty(String key)
      Removes the specified property from this configuration. This implementation performs some preparations and then delegates to clearPropertyDirect(), which will do the real work.
      Specified by:
      clearProperty in interface Configuration
      Parameters:
      key - the key to be removed

    • clearPropertyDirect

      protected void clearPropertyDirect(String key)
      Removes the specified property from this configuration. This method is called by clearProperty() after it has done some preparations. It should be overridden in sub classes. This base implementation is just left empty.
      Parameters:
      key - the key to be removed

    • clear

      public void clear()
      Description copied from interface: Configuration
      Remove all properties from the configuration.
      Specified by:
      clear in interface Configuration

    • getKeys

      public Iterator<String> getKeys(String prefix)
      Get the list of the keys contained in the configuration that match the specified prefix. For instance, if the configuration contains the following keys:
      db.user, db.pwd, db.url, window.xpos, window.ypos,
      an invocation of getKeys("db");
      will return the keys below:
      db.user, db.pwd, db.url.
      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. This implementation returns keys that either match the prefix or start with the prefix followed by a dot ('.'). So the call getKeys("db"); will find the keys db, db.user, or db.password, but not the key dbdriver.
      Specified by:
      getKeys in interface Configuration
      Parameters:
      prefix - The prefix to test against.
      Returns:
      An Iterator of keys that match the prefix.
      See Also:

    • getProperties

      public Properties getProperties(String key)
      Description copied from interface: Configuration
      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 Properties object, the value parts become values.
      Specified by:
      getProperties in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated properties if key is found.

    • getProperties

      public Properties getProperties(String key, Properties defaults)
      Get a list of properties associated with the given configuration key.
      Parameters:
      key - The configuration key.
      defaults - Any default values for the returned Properties object. Ignored if null.
      Returns:
      The associated properties if key is found.
      Throws:
      ConversionException - is thrown if the key maps to an object that is not a String/List of Strings.
      IllegalArgumentException - if one of the tokens is malformed (does not contain an equals sign).

    • getBoolean

      public boolean getBoolean(String key)
      Get a boolean associated with the given configuration key.
      Specified by:
      getBoolean in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated boolean.
      See Also:

    • getBoolean

      public boolean getBoolean(String key, boolean defaultValue)
      Get a boolean associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getBoolean in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated boolean.
      See Also:

    • getBoolean

      public Boolean getBoolean(String key, Boolean defaultValue)
      Obtains the value of the specified key and tries to convert it into a Boolean object. If the property has no value, the passed in default value will be used.
      Specified by:
      getBoolean in interface Configuration
      Parameters:
      key - the key of the property
      defaultValue - the default value
      Returns:
      the value of this key converted to a Boolean
      Throws:
      ConversionException - if the value cannot be converted to a Boolean
      See Also:

    • getByte

      public byte getByte(String key)
      Description copied from interface: Configuration
      Get a byte associated with the given configuration key.
      Specified by:
      getByte in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated byte.

    • getByte

      public byte getByte(String key, byte defaultValue)
      Description copied from interface: Configuration
      Get a byte associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getByte in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated byte.

    • getByte

      public Byte getByte(String key, Byte defaultValue)
      Description copied from interface: Configuration
      Get a Byte associated with the given configuration key.
      Specified by:
      getByte in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated byte if key is found and has valid format, default value otherwise.

    • getDouble

      public double getDouble(String key)
      Description copied from interface: Configuration
      Get a double associated with the given configuration key.
      Specified by:
      getDouble in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated double.

    • getDouble

      public double getDouble(String key, double defaultValue)
      Description copied from interface: Configuration
      Get a double associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getDouble in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated double.

    • getDouble

      public Double getDouble(String key, Double defaultValue)
      Description copied from interface: Configuration
      Get a Double associated with the given configuration key.
      Specified by:
      getDouble in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated double if key is found and has valid format, default value otherwise.

    • getFloat

      public float getFloat(String key)
      Description copied from interface: Configuration
      Get a float associated with the given configuration key.
      Specified by:
      getFloat in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated float.

    • getFloat

      public float getFloat(String key, float defaultValue)
      Description copied from interface: Configuration
      Get a float associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getFloat in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated float.

    • getFloat

      public Float getFloat(String key, Float defaultValue)
      Description copied from interface: Configuration
      Get a Float associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getFloat in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated float if key is found and has valid format, default value otherwise.

    • getInt

      public int getInt(String key)
      Description copied from interface: Configuration
      Get a int associated with the given configuration key.
      Specified by:
      getInt in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated int.

    • getInt

      public int getInt(String key, int defaultValue)
      Description copied from interface: Configuration
      Get a int associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getInt in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated int.

    • getInteger

      public Integer getInteger(String key, Integer defaultValue)
      Description copied from interface: Configuration
      Get an Integer associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getInteger in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated int if key is found and has valid format, default value otherwise.

    • getLong

      public long getLong(String key)
      Description copied from interface: Configuration
      Get a long associated with the given configuration key.
      Specified by:
      getLong in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated long.

    • getLong

      public long getLong(String key, long defaultValue)
      Description copied from interface: Configuration
      Get a long associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getLong in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated long.

    • getLong

      public Long getLong(String key, Long defaultValue)
      Description copied from interface: Configuration
      Get a Long associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getLong in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated long if key is found and has valid format, default value otherwise.

    • getShort

      public short getShort(String key)
      Description copied from interface: Configuration
      Get a short associated with the given configuration key.
      Specified by:
      getShort in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated short.

    • getShort

      public short getShort(String key, short defaultValue)
      Description copied from interface: Configuration
      Get a short associated with the given configuration key.
      Specified by:
      getShort in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated short.

    • getShort

      public Short getShort(String key, Short defaultValue)
      Description copied from interface: Configuration
      Get a Short associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getShort in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated short if key is found and has valid format, default value otherwise.

    • getBigDecimal

      public BigDecimal getBigDecimal(String key)
      Get a BigDecimal associated with the given configuration key.
      Specified by:
      getBigDecimal in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated BigDecimal if key is found and has valid format
      See Also:

    • getBigDecimal

      public BigDecimal getBigDecimal(String key, BigDecimal defaultValue)
      Description copied from interface: Configuration
      Get a BigDecimal associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getBigDecimal in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated BigDecimal if key is found and has valid format, default value otherwise.

    • getBigInteger

      public BigInteger getBigInteger(String key)
      Get a BigInteger associated with the given configuration key.
      Specified by:
      getBigInteger in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated BigInteger if key is found and has valid format
      See Also:

    • getBigInteger

      public BigInteger getBigInteger(String key, BigInteger defaultValue)
      Description copied from interface: Configuration
      Get a BigInteger associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getBigInteger in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated BigInteger if key is found and has valid format, default value otherwise.

    • getString

      public String getString(String key)
      Get a string associated with the given configuration key.
      Specified by:
      getString in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated string.
      See Also:

    • getString

      public String getString(String key, String defaultValue)
      Description copied from interface: Configuration
      Get a string associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.
      Specified by:
      getString in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated string if key is found and has valid format, default value otherwise.

    • getStringArray

      public String[] getStringArray(String key)
      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. If a property is added to a configuration, it is checked whether it contains multiple values. This is obvious if the added object is a list or an array. For strings it is checked whether the string contains the list delimiter character that can be specified using the setListDelimiter() method. If this is the case, the string is split at these positions resulting in a property with multiple values.
      Specified by:
      getStringArray in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      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.
      See Also:

    • getList

      public 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 an empty List is returned.
      Specified by:
      getList in interface Configuration
      Parameters:
      key - The configuration key.
      Returns:
      The associated List.
      See Also:

    • getList

      public List<Object> getList(String key, List<?> defaultValue)
      Description copied from interface: Configuration
      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.
      Specified by:
      getList in interface Configuration
      Parameters:
      key - The configuration key.
      defaultValue - The default value.
      Returns:
      The associated List of strings.

    • resolveContainerStore

      protected Object resolveContainerStore(String key)
      Returns an object from the store described by the key. If the value is a Collection object, replace it with the first object in the collection.
      Parameters:
      key - The property key.
      Returns:
      value Value, transparently resolving a possible collection dependency.

    • isScalarValue

      protected boolean isScalarValue(Object value)
      Checks whether the specified object is a scalar value. This method is called by getList() and getStringArray() if the property requested is not a string, a list, or an array. If it returns true, the calling method transforms the value to a string and returns a list or an array with this single element. This implementation returns true if the value is of a wrapper type for a primitive type.
      Parameters:
      value - the value to be checked
      Returns:
      a flag whether the value is a scalar
      Since:
      1.7

    • copy

      public void copy(Configuration c)
      Copies the content of the specified configuration into this configuration. If the specified configuration contains a key that is also present in this configuration, the value of this key will be replaced by the new value. Note: This method won't work well when copying hierarchical configurations because it is not able to copy information about the properties' structure (i.e. the parent-child-relationships will get lost). So when dealing with hierarchical configuration objects their clone() methods should be used.
      Parameters:
      c - the configuration to copy (can be null, then this operation will have no effect)
      Since:
      1.5

    • append

      public void append(Configuration c)
      Appends the content of the specified configuration to this configuration. The values of all properties contained in the specified configuration will be appended to this configuration. So if a property is already present in this configuration, its new value will be a union of the values in both configurations. Note: This method won't work well when appending hierarchical configurations because it is not able to copy information about the properties' structure (i.e. the parent-child-relationships will get lost). So when dealing with hierarchical configuration objects their clone() methods should be used.
      Parameters:
      c - the configuration to be appended (can be null, then this operation will have no effect)
      Since:
      1.5

    • interpolatedConfiguration

      public Configuration interpolatedConfiguration()
      Returns a configuration with the same content as this configuration, but with all variables replaced by their actual values. This method tries to clone the configuration and then perform interpolation on all properties. So property values of the form ${var} will be resolved as far as possible (if a variable cannot be resolved, it remains unchanged). This operation is useful if the content of a configuration is to be exported or processed by an external component that does not support variable interpolation.
      Returns:
      a configuration with all variables interpolated
      Throws:
      ConfigurationRuntimeException - if this configuration cannot be cloned
      Since:
      1.5