org.apache.avalon.framework/avalon-framework-api/4.3.1 : org/apache/avalon/framework/configuration/Configuration.java

Configuration
http://www.apache.org/excalibur/avalon-framework/avalon-framework-api/: Avalon Framework API (Apache Software Foundation)
The Apache Software License, Version 2.0
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 * (the "License"); you may not use this file except in compliance with
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.avalon.framework.configuration;

Configuration is a interface encapsulating a configuration node
used to retrieve configuration values.

This is a "read only" interface preventing applications from modifying their
own configurations. Once it is created, the information never changes.

Data Model

The data model is a subset of XML's; a single-rooted hierarchical tree where each
node can contain multiple attributes, and leaf nodes can also
contain a value. Reflecting this, Configurations are
usually built from an XML file by the DefaultConfigurationBuilder
class, or directly by a SAX parser using a SAXConfigurationHandler or
NamespacedSAXConfigurationHandler event handler.

Namespace support

Since version 4.1, each Configuration node has a namespace associated with it, in the form of a string, accessible through getNamespace. If no namespace is present, getNamespace will
return blank (""). See DefaultConfigurationBuilder for details on how
XML namespaces are mapped to Configuration namespaces.

Example

As an example, consider two Configurations (with and without
namespaces) built from this XML:

<my-system version="1.3" xmlns:doc="http://myco.com/documentation">
  <doc:desc>This is a highly fictitious config file</doc:desc>
  <widget name="fooWidget" initOrder="1" threadsafe="true"/>
</my-system>

If namespace support is enabled (eg through 
DefaultConfigurationBuilder#DefaultConfigurationBuilder(boolean) new
DefaultConfigurationBuilder(true)), then the xmlns:doc element
will not translate into a Configuration attribute, and the
doc:desc element will become a Configuration node
with name "desc" and namespace "http://myco.com/documentation". The
widget element will have namespace "".

If namespace support is disabled (the default for 
DefaultConfigurationBuilder), the above XML will translate directly to
Configuration nodes. The my-system node will have
an attribute named "xmlns:doc", and a child called "doc:desc".


Assuming the Configuration object is named conf,
here is how the data could be retrieved:


Code No namespaces With namespaces

conf.getName() my-system

conf.getAttributeNames().length
2 1

conf.getChildren().length
2

conf.getAttributeAsFloat("version")
1.3

conf.getChild("widget").getAttribute("name")
fooWidget

conf.getChild("widget") .getAttributeAsBoolean("threadsafe") 
true

conf.getChild("widget").getLocation()
file:///home/jeff/tmp/java/avalon/src/java/new.xconf:4:60

conf.getChild("desc").getName()
desc (see getChild(String)) desc

conf.getChild("doc:desc").getName()
doc:desc doc:desc (see getChild(String))

conf.getChild("desc").getValue()
ConfigurationException This is a highly fictitious config file

conf.getChild("doc:desc").getValue()
This is a highly fictitious config file ConfigurationException

conf.getChild("desc").getNamespace()
  http://myco.com/documentation"



Type-safe utility methods are provided for retrieving attribute and element
values as String, int, long,
float and boolean.

Miscellanea
 Currently, the configuration tree can only be traversed one node at a time, eg., through getChild("foo") or getChildren(). In a future release, it may be possible to access child nodes with an XPath-like syntax. 

Checking for the existence of an attribute can be done as follows:

String value = conf.getAttribute( "myAttribute", null );
if ( null == value )
{
  // Do the processing applicable if the attribute isn't present.
}

Author: Avalon Development Team
Version: $Id: Configuration.java 506231 2007-02-12 02:36:54Z crossley $/**
 * <code>Configuration</code> is a interface encapsulating a configuration node
 * used to retrieve configuration values.
 *
 * <p>
 * This is a "read only" interface preventing applications from modifying their
 * own configurations. Once it is created, the information never changes.
 * </p>
 * <h3>Data Model</h3>
 * <p>
 * The data model is a subset of XML's; a single-rooted hierarchical tree where each
 * node can contain multiple <em>attributes</em>, and leaf nodes can also
 * contain a <em>value</em>. Reflecting this, <code>Configuration</code>s are
 * usually built from an XML file by the DefaultConfigurationBuilder
 * class, or directly by a SAX parser using a SAXConfigurationHandler or
 * NamespacedSAXConfigurationHandler event handler.
 * </p>
 * <h4>Namespace support</h4>
 * <p>
 * Since version 4.1, each <code>Configuration</code> node has a namespace
 * associated with it, in the form of a string, accessible through {@link
 * #getNamespace}. If no namespace is present, <code>getNamespace</code> will
 * return blank (""). See DefaultConfigurationBuilder for details on how
 * XML namespaces are mapped to <code>Configuration</code> namespaces.
 * </p>
 * <h3>Example</h3>
 * <p>
 * As an example, consider two <code>Configuration</code>s (with and without
 * namespaces) built from this XML:
 * </p>
 * <pre>
 * &lt;my-system version="1.3" xmlns:doc="http://myco.com/documentation"&gt;
 *   &lt;doc:desc&gt;This is a highly fictitious config file&lt;/doc:desc&gt;
 *   &lt;widget name="fooWidget" initOrder="1" threadsafe="true"/&gt;
 * &lt;/my-system&gt;
 * </pre>
 * <p>If namespace support is enabled (eg through 
 * DefaultConfigurationBuilder#DefaultConfigurationBuilder(boolean) new
 * DefaultConfigurationBuilder(true)), then the <code>xmlns:doc</code> element
 * will not translate into a Configuration attribute, and the
 * <code>doc:desc</code> element will become a <code>Configuration</code> node
 * with name "desc" and namespace "http://myco.com/documentation". The
 * <code>widget</code> element will have namespace "".
 * </p>
 * <p>If namespace support is disabled (the default for 
 * DefaultConfigurationBuilder), the above XML will translate directly to
 * <code>Configuration</code> nodes. The <code>my-system</code> node will have
 * an attribute named "xmlns:doc", and a child called "doc:desc".
 * </p>
 * <p>
 * Assuming the <code>Configuration</code> object is named <code>conf</code>,
 * here is how the data could be retrieved:
 * </p>
 * <table border="1">
 * <tr align="center"><th>Code</th><th>No namespaces</th><th>With namespaces</th></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getName getName}()</code></td><td colspan="2">my-system</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getAttributeNames getAttributeNames}().length</code>
 * </td><td>2</td><td>1</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChildren() getChildren}().length</code>
 * </td><td colspan="2">2</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getAttributeAsFloat(String) getAttributeAsFloat}("version")</code>
 * </td><td colspan="2">1.3</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("widget").{@link #getAttribute(String) getAttribute}("name")</code>
 * </td><td colspan="2">fooWidget</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("widget")
 * .{@link #getAttributeAsBoolean(String) getAttributeAsBoolean}("threadsafe")</code></td><td colspan="2">
 * <code>true</code></td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("widget").{@link #getLocation getLocation}()</code>
 * </td><td colspan="2">file:///home/jeff/tmp/java/avalon/src/java/new.xconf:4:60</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("desc").{@link #getName getName}()</code>
 * </td><td>desc (see {@link #getChild(String)})</td><td>desc</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("doc:desc").{@link #getName getName}()</code>
 * </td><td>doc:desc</td><td>doc:desc (see {@link #getChild(String)})</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("desc").{@link #getValue() getValue}()</code>
 * </td><td>{@link ConfigurationException}</td><td>This is a highly fictitious config file</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("doc:desc").{@link #getValue() getValue}()</code>
 * </td><td>This is a highly fictitious config file</td><td>{@link ConfigurationException}</td></tr>
 * <tr align="center"><td align="left">
 * <code>conf.{@link #getChild(String) getChild}("desc").{@link #getNamespace getNamespace}()</code>
 * </td><td>&nbsp;</td><td>http://myco.com/documentation"</td></tr>
 * </table>
 * </p>
 * <p>
 * Type-safe utility methods are provided for retrieving attribute and element
 * values as <code>String</code>, <code>int</code>, <code>long</code>,
 * <code>float</code> and <code>boolean</code>.
 * </p>
 * <h3>Miscellanea</h3>
 * <p>
 * Currently, the configuration tree can only be traversed one node at a time,
 * eg., through {@link #getChild(String) getChild("foo")} or {@link #getChildren()}. In
 * a future release, it may be possible to access child nodes with an XPath-like
 * syntax.
 * </p>
 * <p>
 * Checking for the existence of an attribute can be done as follows:
 * </p>
 * <pre>
 *String value = conf.getAttribute( "myAttribute", null );
 * if ( null == value )
 * {
 *   // Do the processing applicable if the attribute isn't present.
 * }
 * </pre>
 *
 * @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
 * @version $Id: Configuration.java 506231 2007-02-12 02:36:54Z crossley $
 */
public interface Configuration
{
    Return the name of the node.
Returns: name of the Configuration node./**
     * Return the name of the node.
     *
     * @return name of the <code>Configuration</code> node.
     */
    String getName();

    Return a string describing location of Configuration.
Location can be different for different mediums (ie "file:line" for normal XML files or
"table:primary-key" for DB based configurations);
Returns: a string describing location of Configuration/**
     * Return a string describing location of Configuration.
     * Location can be different for different mediums (ie "file:line" for normal XML files or
     * "table:primary-key" for DB based configurations);
     *
     * @return a string describing location of Configuration
     */
    String getLocation();

    Returns a string indicating which namespace this Configuration node
belongs to.

What this returns is dependent on the configuration file and the
Configuration builder. If the Configuration builder does not support
namespaces, this method will return a blank string.

In the case of DefaultConfigurationBuilder, the namespace will
be the URI associated with the XML element. Eg.,:
<foo xmlns:x="http://blah.com">
  <x:bar/>
</foo>

The namespace of foo will be "", and the namespace of
bar will be "http://blah.com".
Throws: ConfigurationException – if an error occurs
Returns: a String identifying the namespace of this Configuration.
Since: 4.1/**
     * Returns a string indicating which namespace this Configuration node
     * belongs to.
     *
     * <p>
     * What this returns is dependent on the configuration file and the
     * Configuration builder. If the Configuration builder does not support
     * namespaces, this method will return a blank string.
     * </p>
     * <p>In the case of DefaultConfigurationBuilder, the namespace will
     * be the URI associated with the XML element. Eg.,:</p>
     * <pre>
     * &lt;foo xmlns:x="http://blah.com"&gt;
     *   &lt;x:bar/&gt;
     * &lt;/foo&gt;
     * </pre>
     * <p>The namespace of <code>foo</code> will be "", and the namespace of
     * <code>bar</code> will be "http://blah.com".</p>
     *
     * @return a String identifying the namespace of this Configuration.
     * @throws ConfigurationException if an error occurs
     * @since 4.1
     */
    String getNamespace() throws ConfigurationException;

    Return a new Configuration instance encapsulating the
specified child node.

If no such child node exists, an empty Configuration will be
returned, allowing constructs such as
conf.getChild("foo").getChild("bar").getChild("baz").getValue("default");


If you wish to get a null return when no element is present, use getChild("foo", false). 
Params: child – The name of the child node.
Returns: Configuration/**
     * Return a new <code>Configuration</code> instance encapsulating the
     * specified child node.
     * <p>
     * If no such child node exists, an empty <code>Configuration</code> will be
     * returned, allowing constructs such as
     * <code>conf.getChild("foo").getChild("bar").getChild("baz").{@link
     * #getValue(String) getValue}("default");</code>
     * </p>
     * <p>
     * If you wish to get a <code>null</code> return when no element is present,
     * use {@link #getChild(String, boolean) getChild("foo", <b>false</b>)}.
     * </p>
     *
     * @param child The name of the child node.
     * @return Configuration
     */
    Configuration getChild( String child );

    Return a Configuration instance encapsulating the specified
child node.
Params: child – The name of the child node.
createNew – If true, a new Configuration
will be created and returned if the specified child does not exist. If
false, null will be returned when the specified
child doesn't exist.
Returns: Configuration/**
     * Return a <code>Configuration</code> instance encapsulating the specified
     * child node.
     *
     * @param child The name of the child node.
     * @param createNew If <code>true</code>, a new <code>Configuration</code>
     * will be created and returned if the specified child does not exist. If
     * <code>false</code>, <code>null</code> will be returned when the specified
     * child doesn't exist.
     * @return Configuration
     */
    Configuration getChild( String child, boolean createNew );

    Return an Array of Configuration
elements containing all node children. The array order will reflect the
order in the source config file.
Returns: All child nodes/**
     * Return an <code>Array</code> of <code>Configuration</code>
     * elements containing all node children. The array order will reflect the
     * order in the source config file.
     *
     * @return All child nodes
     */
    Configuration[] getChildren();

    Return an Array of Configuration
elements containing all node children with the specified name. The array
order will reflect the order in the source config file.
Params: name – The name of the children to get.
Returns: The child nodes with name name/**
     * Return an <code>Array</code> of <code>Configuration</code>
     * elements containing all node children with the specified name. The array
     * order will reflect the order in the source config file.
     *
     * @param name The name of the children to get.
     * @return The child nodes with name <code>name</code>
     */
    Configuration[] getChildren( String name );

    Return an array of all attribute names.

The order of attributes in this array can not be relied on. As
with XML, a Configuration's attributes are an
unordered set. If your code relies on order, eg
conf.getAttributeNames()[0], then it is liable to break if a
different XML parser is used.

Returns: a String[] value/**
     * Return an array of all attribute names.
     * <p>
     * <em>The order of attributes in this array can not be relied on.</em> As
     * with XML, a <code>Configuration</code>'s attributes are an
     * <em>unordered</em> set. If your code relies on order, eg
     * <tt>conf.getAttributeNames()[0]</tt>, then it is liable to break if a
     * different XML parser is used.
     * </p>
     * @return a <code>String[]</code> value
     */
    String[] getAttributeNames();

    Return the value of specified attribute.
Params: paramName – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no attribute with that name exists.
Returns: String value of attribute./**
     * Return the value of specified attribute.
     *
     * @param paramName The name of the parameter you ask the value of.
     * @return String value of attribute.
     * @throws ConfigurationException If no attribute with that name exists.
     */
    String getAttribute( String paramName ) throws ConfigurationException;

    Return the int value of the specified attribute contained
in this node.
Params: paramName – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no parameter with that name exists.
                                  or if conversion to int fails.
Returns: int value of attribute/**
     * Return the <code>int</code> value of the specified attribute contained
     * in this node.
     *
     * @param paramName The name of the parameter you ask the value of.
     * @return int value of attribute
     * @throws ConfigurationException If no parameter with that name exists.
     *                                   or if conversion to <code>int</code> fails.
     *
     */
    int getAttributeAsInteger( String paramName ) throws ConfigurationException;

    Returns the value of the attribute specified by its name as a
long.
Params: name – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no parameter with that name exists.
                                  or if conversion to long fails.
Returns: long value of attribute/**
     * Returns the value of the attribute specified by its name as a
     * <code>long</code>.
     *
     * @param name The name of the parameter you ask the value of.
     * @return long value of attribute
     * @throws ConfigurationException If no parameter with that name exists.
     *                                   or if conversion to <code>long</code> fails.
     */
    long getAttributeAsLong( String name ) throws ConfigurationException;

    Return the float value of the specified parameter contained
in this node.
Params: paramName – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no parameter with that name exists.
                                  or if conversion to float fails.
Returns: float value of attribute/**
     * Return the <code>float</code> value of the specified parameter contained
     * in this node.
     *
     * @param paramName The name of the parameter you ask the value of.
     * @return float value of attribute
     * @throws ConfigurationException If no parameter with that name exists.
     *                                   or if conversion to <code>float</code> fails.
     */
    float getAttributeAsFloat( String paramName ) throws ConfigurationException;

    Return the double value of the specified parameter contained
in this node.
Params: paramName – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no parameter with that name exists.
                                  or if conversion to double fails.
Returns: double value of attribute/**
     * Return the <code>double</code> value of the specified parameter contained
     * in this node.
     *
     * @param paramName The name of the parameter you ask the value of.
     * @return double value of attribute
     * @throws ConfigurationException If no parameter with that name exists.
     *                                   or if conversion to <code>double</code> fails.
     */
    double getAttributeAsDouble( String paramName ) throws ConfigurationException;

    Return the boolean value of the specified parameter contained
in this node.
Params: paramName – The name of the parameter you ask the value of.
Throws: ConfigurationException – If no parameter with that name exists.
                                  or if conversion to boolean fails.
Returns: boolean value of attribute/**
     * Return the <code>boolean</code> value of the specified parameter contained
     * in this node.
     *
     * @param paramName The name of the parameter you ask the value of.
     * @return boolean value of attribute
     * @throws ConfigurationException If no parameter with that name exists.
     *                                   or if conversion to <code>boolean</code> fails.
     */
    boolean getAttributeAsBoolean( String paramName ) throws ConfigurationException;

    Return the String value of the node.
Throws: ConfigurationException – if an error occurs
Returns: the value of the node./**
     * Return the <code>String</code> value of the node.
     *
     * @return the value of the node.
     * @throws ConfigurationException if an error occurs
     */
    String getValue() throws ConfigurationException;

    Return the int value of the node.
Throws: ConfigurationException – If conversion to int fails.
Returns: the value of the node./**
     * Return the <code>int</code> value of the node.
     *
     * @return the value of the node.
     *
     * @throws ConfigurationException If conversion to <code>int</code> fails.
     */
    int getValueAsInteger() throws ConfigurationException;

    Return the float value of the node.
Throws: ConfigurationException – If conversion to float fails.
Returns: the value of the node./**
     * Return the <code>float</code> value of the node.
     *
     * @return the value of the node.
     * @throws ConfigurationException If conversion to <code>float</code> fails.
     */
    float getValueAsFloat() throws ConfigurationException;

    Return the double value of the node.
Throws: ConfigurationException – If conversion to double fails.
Returns: the value of the node./**
     * Return the <code>double</code> value of the node.
     *
     * @return the value of the node.
     * @throws ConfigurationException If conversion to <code>double</code> fails.
     */
    double getValueAsDouble() throws ConfigurationException;

    Return the boolean value of the node.
Throws: ConfigurationException – If conversion to boolean fails.
Returns: the value of the node./**
     * Return the <code>boolean</code> value of the node.
     *
     * @return the value of the node.
     * @throws ConfigurationException If conversion to <code>boolean</code> fails.
     */
    boolean getValueAsBoolean() throws ConfigurationException;

    Return the long value of the node.
Throws: ConfigurationException – If conversion to long fails.
Returns: the value of the node./**
     * Return the <code>long</code> value of the node.
     *
     * @return the value of the node.
     * @throws ConfigurationException If conversion to <code>long</code> fails.
     */
    long getValueAsLong() throws ConfigurationException;

    Returns the value of the configuration element as a String.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: String value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as a <code>String</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return String value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    String getValue( String defaultValue );

    Returns the value of the configuration element as an int.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: int value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as an <code>int</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return int value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    int getValueAsInteger( int defaultValue );

    Returns the value of the configuration element as a long.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: long value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as a <code>long</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return long value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    long getValueAsLong( long defaultValue );

    Returns the value of the configuration element as a float.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: float value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as a <code>float</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return float value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    float getValueAsFloat( float defaultValue );

    Returns the value of the configuration element as a double.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: float value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as a <code>double</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return float value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    double getValueAsDouble( double defaultValue );

    Returns the value of the configuration element as a boolean.
If the configuration value is not set, the default value will be
used.
Params: defaultValue – The default value desired.
Returns: boolean value of the Configuration, or default
         if none specified./**
     * Returns the value of the configuration element as a <code>boolean</code>.
     * If the configuration value is not set, the default value will be
     * used.
     *
     * @param defaultValue The default value desired.
     * @return boolean value of the <code>Configuration</code>, or default
     *          if none specified.
     */
    boolean getValueAsBoolean( boolean defaultValue );

    Returns the value of the attribute specified by its name as a
String, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: String value of attribute. It will return the default
        value if the named attribute does not exist, or if
        the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>String</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return String value of attribute. It will return the default
     *         value if the named attribute does not exist, or if
     *         the value is not set.
     */
    String getAttribute( String name, String defaultValue );

    Returns the value of the attribute specified by its name as a
int, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: int value of attribute. It will return the default
        value if the named attribute does not exist, or if
        the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>int</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return int value of attribute. It will return the default
     *         value if the named attribute does not exist, or if
     *         the value is not set.
     */
    int getAttributeAsInteger( String name, int defaultValue );

    Returns the value of the attribute specified by its name as a
long, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: long value of attribute. It will return the default
         value if the named attribute does not exist, or if
         the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>long</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return long value of attribute. It will return the default
     *          value if the named attribute does not exist, or if
     *          the value is not set.
     */
    long getAttributeAsLong( String name, long defaultValue );

    Returns the value of the attribute specified by its name as a
float, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: float value of attribute. It will return the default
         value if the named attribute does not exist, or if
         the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>float</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return float value of attribute. It will return the default
     *          value if the named attribute does not exist, or if
     *          the value is not set.
     */
    float getAttributeAsFloat( String name, float defaultValue );

    Returns the value of the attribute specified by its name as a
double, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: float value of attribute. It will return the default
         value if the named attribute does not exist, or if
         the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>double</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return float value of attribute. It will return the default
     *          value if the named attribute does not exist, or if
     *          the value is not set.
     */
    double getAttributeAsDouble( String name, double defaultValue );

    Returns the value of the attribute specified by its name as a
boolean, or the default value if no attribute by
that name exists or is empty.
Params: name – The name of the attribute you ask the value of.
defaultValue – The default value desired.
Returns: boolean value of attribute. It will return the default
        value if the named attribute does not exist, or if
        the value is not set./**
     * Returns the value of the attribute specified by its name as a
     * <code>boolean</code>, or the default value if no attribute by
     * that name exists or is empty.
     *
     * @param name The name of the attribute you ask the value of.
     * @param defaultValue The default value desired.
     * @return boolean value of attribute. It will return the default
     *         value if the named attribute does not exist, or if
     *         the value is not set.
     */
    boolean getAttributeAsBoolean( String name, boolean defaultValue );
}
Code	No namespaces	With namespaces
`conf.getName()`	my-system
`conf.getAttributeNames().length`	2	1
`conf.getChildren().length`	2
`conf.getAttributeAsFloat("version")`	1.3
`conf.getChild("widget").getAttribute("name")`	fooWidget
`conf.getChild("widget") .getAttributeAsBoolean("threadsafe")`	`true`
`conf.getChild("widget").getLocation()`	file:///home/jeff/tmp/java/avalon/src/java/new.xconf:4:60
`conf.getChild("desc").getName()`	desc (see `getChild(String)`)	desc
`conf.getChild("doc:desc").getName()`	doc:desc	doc:desc (see `getChild(String)`)
`conf.getChild("desc").getValue()`	`ConfigurationException`	This is a highly fictitious config file
`conf.getChild("doc:desc").getValue()`	This is a highly fictitious config file	`ConfigurationException`
`conf.getChild("desc").getNamespace()`		http://myco.com/documentation"
Author:	Avalon Development Team
Version:	$Id: Configuration.java 506231 2007-02-12 02:36:54Z crossley $
Throws:	ConfigurationException – if an error occurs
Returns:	a String identifying the namespace of this Configuration.
Since:	4.1
Params:	child – The name of the child node.
Returns:	Configuration
Params:	child – The name of the child node. createNew – If `true`, a new `Configuration` will be created and returned if the specified child does not exist. If `false`, `null` will be returned when the specified child doesn't exist.
Returns:	Configuration
Params:	name – The name of the children to get.
Returns:	The child nodes with name `name`
Params:	paramName – The name of the parameter you ask the value of.
Throws:	ConfigurationException – If no attribute with that name exists.
Returns:	String value of attribute.
Params:	name – The name of the parameter you ask the value of.
Throws:	ConfigurationException – If no parameter with that name exists. or if conversion to `long` fails.
Returns:	long value of attribute
Throws:	ConfigurationException – If conversion to `int` fails.
Returns:	the value of the node.
Params:	defaultValue – The default value desired.
Returns:	String value of the `Configuration`, or default if none specified.
Params:	name – The name of the attribute you ask the value of. defaultValue – The default value desired.
Returns:	String value of attribute. It will return the default value if the named attribute does not exist, or if the value is not set.
/

org.apache.avalon.framework/ avalon-framework-api/ 4.3.1/ org/apache/avalon/framework/configuration/Configuration.java

Data Model

Namespace support

Example

Miscellanea
