Configuration (Apache Hadoop Main 0.23.11 API)

java.lang.Object
- org.apache.hadoop.conf.Configuration

All Implemented Interfaces:

Iterable<Map.Entry<String,String>>, Writable

Direct Known Subclasses:

JobConf
```
@InterfaceAudience.Public
@InterfaceStability.Stable
public class Configuration
extends Object
implements Iterable<Map.Entry<String,String>>, Writable
```
Provides access to configuration parameters.
Resources

Configurations are specified by resources. A resource contains a set of name/value pairs as XML data. Each resource is named by either a String or by a Path. If named by a String, then the classpath is examined for a file with that name. If named by a Path, then the local filesystem is examined directly, without referring to the classpath.
Unless explicitly turned off, Hadoop by default specifies two resources, loaded in-order from the classpath:
1. core-default.xml: Read-only defaults for hadoop.
2. core-site.xml: Site-specific configuration for a given hadoop installation.
Applications may add additional resources, which are loaded subsequent to these resources in the order they are added.
Final Parameters

Configuration parameters may be declared final. Once a resource declares a value final, no subsequently-loaded resource can alter that value. For example, one might define a final parameter with:
```
 <property>
 <name>dfs.client.buffer.dir</name>
 <value>/tmp/hadoop/dfs/client</value>
 <final>true</final>
 </property>
```
Administrators typically define parameters as final in core-site.xml for values that user applications may not alter.
Variable Expansion

Value strings are first processed for variable expansion. The available properties are:
1. Other properties defined in this Configuration; and, if a name is undefined here,
2. Properties in System.getProperties().
For example, if a configuration resource contains the following property definitions:
```
 <property>
 <name>basedir</name>
 <value>/user/${user.name}</value>
 </property>
 
 <property>
 <name>tempdir</name>
 <value>${basedir}/tmp</value>
 </property>
```
When conf.get("tempdir") is called, then ${basedir} will be resolved to another property in this Configuration, while ${user.name} would then ordinarily be resolved to the value of the System property with that name.

Constructor Summary

Constructors
Constructor and Description
`Configuration()` A new configuration.
`Configuration(boolean loadDefaults)` A new configuration where the behavior of reading from the default resources can be turned off.
`Configuration(Configuration other)` A new configuration with the same settings cloned from another.

Method Summary

Methods
Modifier and Type	Method and Description
`static void`	`addDefaultResource(String name)` Add a default resource.
`static void`	`addDeprecation(String key, String newKey)` Adds the deprecated key to the deprecation map when no custom message is provided.
`static void`	`addDeprecation(String key, String[] newKeys)` Deprecated. use `addDeprecation(String key, String newKey)` instead
`static void`	`addDeprecation(String key, String[] newKeys, String customMessage)` Deprecated. use `addDeprecation(String key, String newKey, String customMessage)` instead
`static void`	`addDeprecation(String key, String newKey, String customMessage)` Adds the deprecated key to the deprecation map.
`void`	`addResource(InputStream in)` Add a configuration resource.
`void`	`addResource(InputStream in, String name)` Add a configuration resource.
`void`	`addResource(Path file)` Add a configuration resource.
`void`	`addResource(String name)` Add a configuration resource.
`void`	`addResource(URL url)` Add a configuration resource.
`void`	`clear()` Clears all keys from the configuration.
`static void`	`dumpConfiguration(Configuration config, Writer out)` Writes out all the parameters and their properties (final and resource) to the given `Writer` The format of the output would be { "properties" : [ {key1,value1,key1.isFinal,key1.resource}, {key2,value2, key2.isFinal,key2.resource}...
`String`	`get(String name)` Get the value of the `name` property, `null` if no such property exists.
`String`	`get(String name, String defaultValue)` Get the value of the `name`.
`boolean`	`getBoolean(String name, boolean defaultValue)` Get the value of the `name` property as a `boolean`.
`Class<?>`	`getClass(String name, Class<?> defaultValue)` Get the value of the `name` property as a `Class`.
`<U> Class<? extends U>`	`getClass(String name, Class<? extends U> defaultValue, Class<U> xface)` Get the value of the `name` property as a `Class` implementing the interface specified by `xface`.
`Class<?>`	`getClassByName(String name)` Load a class by name.
`Class<?>`	`getClassByNameOrNull(String name)` Load a class by name, returning null rather than throwing an exception if it couldn't be loaded.
`Class<?>[]`	`getClasses(String name, Class<?>... defaultValue)` Get the value of the `name` property as an array of `Class`.
`ClassLoader`	`getClassLoader()` Get the `ClassLoader` for this job.
`InputStream`	`getConfResourceAsInputStream(String name)` Get an input stream attached to the configuration resource with the given `name`.
`Reader`	`getConfResourceAsReader(String name)` Get a `Reader` attached to the configuration resource with the given `name`.
`<T extends Enum<T>> T`	`getEnum(String name, T defaultValue)` Return value matching this enumerated type.
`File`	`getFile(String dirsProp, String path)` Get a local file name under a directory named in dirsProp with the given path.
`Set<String>`	`getFinalParameters()` Get the set of parameters marked final.
`float`	`getFloat(String name, float defaultValue)` Get the value of the `name` property as a `float`.
`<U> List<U>`	`getInstances(String name, Class<U> xface)` Get the value of the `name` property as a `List` of objects implementing the interface specified by `xface`.
`int`	`getInt(String name, int defaultValue)` Get the value of the `name` property as an `int`.
`Path`	`getLocalPath(String dirsProp, String path)` Get a local file under a directory named by dirsProp with the given path.
`long`	`getLong(String name, long defaultValue)` Get the value of the `name` property as a `long`.
`long`	`getLongBytes(String name, long defaultValue)` Get the value of the `name` property as a `long` or human readable format.
`Pattern`	`getPattern(String name, Pattern defaultValue)` Get the value of the `name` property as a `Pattern`.
`String[]`	`getPropertySources(String name)` Gets information about why a property was set.
`protected Properties`	`getProps()`
`org.apache.hadoop.conf.Configuration.IntegerRanges`	`getRange(String name, String defaultValue)` Parse the given attribute as a set of integer ranges
`String`	`getRaw(String name)` Get the value of the `name` property, without doing variable expansion.If the key is deprecated, it returns the value of the first key which replaces the deprecated key and is not null.
`URL`	`getResource(String name)` Get the `URL` for the named resource.
`InetSocketAddress`	`getSocketAddr(String name, String defaultAddress, int defaultPort)` Get the socket address for `name` property as a `InetSocketAddress`.
`Collection<String>`	`getStringCollection(String name)` Get the comma delimited values of the `name` property as a collection of `String`s.
`String[]`	`getStrings(String name)` Get the comma delimited values of the `name` property as an array of `String`s.
`String[]`	`getStrings(String name, String... defaultValue)` Get the comma delimited values of the `name` property as an array of `String`s.
`String`	`getTrimmed(String name)` Get the value of the `name` property as a trimmed `String`, `null` if no such property exists.
`Collection<String>`	`getTrimmedStringCollection(String name)` Get the comma delimited values of the `name` property as a collection of `String`s, trimmed of the leading and trailing whitespace.
`String[]`	`getTrimmedStrings(String name)` Get the comma delimited values of the `name` property as an array of `String`s, trimmed of the leading and trailing whitespace.
`String[]`	`getTrimmedStrings(String name, String... defaultValue)` Get the comma delimited values of the `name` property as an array of `String`s, trimmed of the leading and trailing whitespace.
`Map<String,String>`	`getValByRegex(String regex)` get keys matching the the regex
`static boolean`	`isDeprecated(String key)` checks whether the given `key` is deprecated.
`Iterator<Map.Entry<String,String>>`	`iterator()` Get an `Iterator` to go through the list of `String` key-value pairs in the configuration.
`static void`	`main(String[] args)` For debugging.
`void`	`readFields(DataInput in)` Deserialize the fields of this object from `in`.
`void`	`reloadConfiguration()` Reload configuration from previously added resources.
`void`	`set(String name, String value)` Set the `value` of the `name` property.
`void`	`set(String name, String value, String source)` Set the `value` of the `name` property.
`void`	`setBoolean(String name, boolean value)` Set the value of the `name` property to a `boolean`.
`void`	`setBooleanIfUnset(String name, boolean value)` Set the given property, if it is currently unset.
`void`	`setClass(String name, Class<?> theClass, Class<?> xface)` Set the value of the `name` property to the name of a `theClass` implementing the given interface `xface`.
`void`	`setClassLoader(ClassLoader classLoader)` Set the class loader that will be used to load the various objects.
`<T extends Enum<T>> void`	`setEnum(String name, T value)` Set the value of the `name` property to the given type.
`void`	`setFloat(String name, float value)` Set the value of the `name` property to a `float`.
`void`	`setIfUnset(String name, String value)` Sets a property if it is currently unset.
`void`	`setInt(String name, int value)` Set the value of the `name` property to an `int`.
`void`	`setLong(String name, long value)` Set the value of the `name` property to a `long`.
`void`	`setPattern(String name, Pattern pattern)` Set the given property to `Pattern`.
`void`	`setQuietMode(boolean quietmode)` Set the quietness-mode.
`void`	`setSocketAddr(String name, InetSocketAddress addr)` Set the socket address for the `name` property as a `host:port`.
`void`	`setStrings(String name, String... values)` Set the array of string values for the `name` property as as comma delimited values.
`int`	`size()` Return the number of keys in the configuration.
`String`	`toString()`
`void`	`unset(String name)` Unset a previously set property.
`InetSocketAddress`	`updateConnectAddr(String name, InetSocketAddress addr)` Set the socket address a client can use to connect for the `name` property as a `host:port`.
`void`	`write(DataOutput out)` Serialize the fields of this object to `out`.
`void`	`writeXml(OutputStream out)` Write out the non-default properties in this configuration to the given `OutputStream`.
`void`	`writeXml(Writer out)` Write out the non-default properties in this configuration to the given `Writer`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
 - Configuration
```
public Configuration()
```
 A new configuration.
 - Configuration
```
public Configuration(boolean loadDefaults)
```
 A new configuration where the behavior of reading from the default resources can be turned off. If the parameter loadDefaults is false, the new instance will not load resources from the default files.
 
 Parameters:
 loadDefaults - specifies whether to load from the default files
 - Configuration
```
public Configuration(Configuration other)
```
 A new configuration with the same settings cloned from another.
 
 Parameters:
 other - the configuration from which to clone settings.
- Method Detail
 - addDeprecation
```
@Deprecated
public static void addDeprecation(String key,
 String[] newKeys,
 String customMessage)
```
 Deprecated. use addDeprecation(String key, String newKey, String customMessage) instead
 
 Adds the deprecated key to the deprecation map. It does not override any existing entries in the deprecation map. This is to be used only by the developers in order to add deprecation of keys, and attempts to call this method after loading resources once, would lead to UnsupportedOperationException If a key is deprecated in favor of multiple keys, they are all treated as aliases of each other, and setting any one of them resets all the others to the new value.
 
 Parameters:
 key -
 newKeys -
 customMessage -
 - addDeprecation
```
public static void addDeprecation(String key,
 String newKey,
 String customMessage)
```
 Adds the deprecated key to the deprecation map. It does not override any existing entries in the deprecation map. This is to be used only by the developers in order to add deprecation of keys, and attempts to call this method after loading resources once, would lead to UnsupportedOperationException
 
 Parameters:
 key -
 newKey -
 customMessage -
 - addDeprecation
```
@Deprecated
public static void addDeprecation(String key,
 String[] newKeys)
```
 Deprecated. use addDeprecation(String key, String newKey) instead
 
 Adds the deprecated key to the deprecation map when no custom message is provided. It does not override any existing entries in the deprecation map. This is to be used only by the developers in order to add deprecation of keys, and attempts to call this method after loading resources once, would lead to UnsupportedOperationException If a key is deprecated in favor of multiple keys, they are all treated as aliases of each other, and setting any one of them resets all the others to the new value.
 
 Parameters:
 key - Key that is to be deprecated
 newKeys - list of keys that take up the values of deprecated key
 - addDeprecation
```
public static void addDeprecation(String key,
 String newKey)
```
 Adds the deprecated key to the deprecation map when no custom message is provided. It does not override any existing entries in the deprecation map. This is to be used only by the developers in order to add deprecation of keys, and attempts to call this method after loading resources once, would lead to UnsupportedOperationException
 
 Parameters:
 key - Key that is to be deprecated
 newKey - key that takes up the value of deprecated key
 - isDeprecated
```
public static boolean isDeprecated(String key)
```
 checks whether the given key is deprecated.
 
 Parameters:
 key - the parameter which is to be checked for deprecation
 
 Returns:
 true if the key is deprecated and false otherwise.
 - addDefaultResource
```
public static void addDefaultResource(String name)
```
 Add a default resource. Resources are loaded in the order of the resources added.
 
 Parameters:
 name - file name. File should be present in the classpath.
 - addResource
```
public void addResource(String name)
```
 Add a configuration resource. The properties of this resource will override properties of previously added resources, unless they were marked final.
 
 Parameters:
 name - resource to be added, the classpath is examined for a file with that name.
 - addResource
```
public void addResource(URL url)
```
 Add a configuration resource. The properties of this resource will override properties of previously added resources, unless they were marked final.
 
 Parameters:
 url - url of the resource to be added, the local filesystem is examined directly to find the resource, without referring to the classpath.
 - addResource
```
public void addResource(Path file)
```
 Add a configuration resource. The properties of this resource will override properties of previously added resources, unless they were marked final.
 
 Parameters:
 file - file-path of resource to be added, the local filesystem is examined directly to find the resource, without referring to the classpath.
 - addResource
```
public void addResource(InputStream in)
```
 Add a configuration resource. The properties of this resource will override properties of previously added resources, unless they were marked final. WARNING: The contents of the InputStream will be cached, by this method. So use this sparingly because it does increase the memory consumption.
 
 Parameters:
 in - InputStream to deserialize the object from. In will be read from when a get or set is called next. After it is read the stream will be closed.
 - addResource
```
public void addResource(InputStream in,
 String name)
```
 Add a configuration resource. The properties of this resource will override properties of previously added resources, unless they were marked final.
 
 Parameters:
 in - InputStream to deserialize the object from.
 name - the name of the resource because InputStream.toString is not very descriptive some times.
 - reloadConfiguration
```
public void reloadConfiguration()
```
 Reload configuration from previously added resources. This method will clear all the configuration read from the added resources, and final parameters. This will make the resources to be read again before accessing the values. Values that are added via set methods will overlay values read from the resources.
 - get
```
public String get(String name)
```
 Get the value of the name property, null if no such property exists. If the key is deprecated, it returns the value of the first key which replaces the deprecated key and is not null Values are processed for variable expansion before being returned.
 
 Parameters:
 name - the property name.
 
 Returns:
 the value of the name or its replacing property, or null if no such property exists.
 - getTrimmed
```
public String getTrimmed(String name)
```
 Get the value of the name property as a trimmed String, null if no such property exists. If the key is deprecated, it returns the value of the first key which replaces the deprecated key and is not null Values are processed for variable expansion before being returned.
 
 Parameters:
 name - the property name.
 
 Returns:
 the value of the name or its replacing property, or null if no such property exists.
 - getRaw
```
public String getRaw(String name)
```
 Get the value of the name property, without doing variable expansion.If the key is deprecated, it returns the value of the first key which replaces the deprecated key and is not null.
 
 Parameters:
 name - the property name.
 
 Returns:
 the value of the name property or its replacing property and null if no such property exists.
 - set
```
public void set(String name,
 String value)
```
 Set the value of the name property. If name is deprecated or there is a deprecated name associated to it, it sets the value to both names.
 
 Parameters:
 name - property name.
 value - property value.
 - set
```
public void set(String name,
 String value,
 String source)
```
 Set the value of the name property. If name is deprecated or there is a deprecated name associated to it, it sets the value to both names.
 
 Parameters:
 name - property name.
 value - property value.
 source - the place that this configuration value came from (For debugging).
 - unset
```
public void unset(String name)
```
 Unset a previously set property.
 - setIfUnset
```
public void setIfUnset(String name,
 String value)
```
 Sets a property if it is currently unset.
 
 Parameters:
 name - the property name
 value - the new value
 - get
```
public String get(String name,
 String defaultValue)
```
 Get the value of the name. If the key is deprecated, it returns the value of the first key which replaces the deprecated key and is not null. If no such property exists, then defaultValue is returned.
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value, or defaultValue if the property doesn't exist.
 - getInt
```
public int getInt(String name,
 int defaultValue)
```
 Get the value of the name property as an int. If no such property exists, the provided default value is returned, or if the specified value is not a valid int, then an error is thrown.
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value as an int, or defaultValue.
 
 Throws:
 
 NumberFormatException - when the value is invalid
 - setInt
```
public void setInt(String name,
 int value)
```
 Set the value of the name property to an int.
 
 Parameters:
 name - property name.
 value - int value of the property.
 - getLong
```
public long getLong(String name,
 long defaultValue)
```
 Get the value of the name property as a long. If no such property exists, the provided default value is returned, or if the specified value is not a valid long, then an error is thrown.
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value as a long, or defaultValue.
 
 Throws:
 
 NumberFormatException - when the value is invalid
 - getLongBytes
```
public long getLongBytes(String name,
 long defaultValue)
```
 Get the value of the name property as a long or human readable format. If no such property exists, the provided default value is returned, or if the specified value is not a valid long or human readable format, then an error is thrown. You can use the following suffix (case insensitive): k(kilo), m(mega), g(giga), t(tera), p(peta), e(exa)
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value as a long, or defaultValue.
 
 Throws:
 
 NumberFormatException - when the value is invalid
 - setLong
```
public void setLong(String name,
 long value)
```
 Set the value of the name property to a long.
 
 Parameters:
 name - property name.
 value - long value of the property.
 - getFloat
```
public float getFloat(String name,
 float defaultValue)
```
 Get the value of the name property as a float. If no such property exists, the provided default value is returned, or if the specified value is not a valid float, then an error is thrown.
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value as a float, or defaultValue.
 
 Throws:
 
 NumberFormatException - when the value is invalid
 - setFloat
```
public void setFloat(String name,
 float value)
```
 Set the value of the name property to a float.
 
 Parameters:
 name - property name.
 value - property value.
 - getBoolean
```
public boolean getBoolean(String name,
 boolean defaultValue)
```
 Get the value of the name property as a boolean. If no such property is specified, or if the specified value is not a valid boolean, then defaultValue is returned.
 
 Parameters:
 name - property name.
 defaultValue - default value.
 
 Returns:
 property value as a boolean, or defaultValue.
 - setBoolean
```
public void setBoolean(String name,
 boolean value)
```
 Set the value of the name property to a boolean.
 
 Parameters:
 name - property name.
 value - boolean value of the property.
 - setBooleanIfUnset
```
public void setBooleanIfUnset(String name,
 boolean value)
```
 Set the given property, if it is currently unset.
 
 Parameters:
 name - property name
 value - new value
 - setEnum
```
public <T extends Enum<T>> void setEnum(String name,
 T value)
```
 Set the value of the name property to the given type. This is equivalent to set(<name>, value.toString()).
 
 Parameters:
 name - property name
 value - new value
 - getEnum
```
public <T extends Enum<T>> T getEnum(String name,
 T defaultValue)
```
 Return value matching this enumerated type.
 
 Parameters:
 name - Property name
 defaultValue - Value returned if no mapping exists
 
 Throws:
 
 IllegalArgumentException - If mapping is illegal for the type provided
 - getPattern
```
public Pattern getPattern(String name,
 Pattern defaultValue)
```
 Get the value of the name property as a Pattern. If no such property is specified, or if the specified value is not a valid Pattern, then DefaultValue is returned.
 
 Parameters:
 name - property name
 defaultValue - default value
 
 Returns:
 property value as a compiled Pattern, or defaultValue
 - setPattern
```
public void setPattern(String name,
 Pattern pattern)
```
 Set the given property to Pattern. If the pattern is passed as null, sets the empty pattern which results in further calls to getPattern(...) returning the default value.
 
 Parameters:
 name - property name
 pattern - new value
 - getPropertySources
```
@InterfaceStability.Unstable
public String[] getPropertySources(String name)
```
 Gets information about why a property was set. Typically this is the path to the resource objects (file, URL, etc.) the property came from, but it can also indicate that it was set programatically, or because of the command line.
 
 Parameters:
 name - - The property name to get the source of.
 
 Returns:
 null - If the property or its source wasn't found. Otherwise, returns a list of the sources of the resource. The older sources are the first ones in the list. So for example if a configuration is set from the command line, and then written out to a file that is read back in the first entry would indicate that it was set from the command line, while the second one would indicate the file that the new configuration was read in from.
 - getRange
```
public org.apache.hadoop.conf.Configuration.IntegerRanges getRange(String name,
 String defaultValue)
```
 Parse the given attribute as a set of integer ranges
 
 Parameters:
 name - the attribute name
 defaultValue - the default value if it is not set
 
 Returns:
 a new set of ranges from the configured value
 - getStringCollection
```
public Collection<String> getStringCollection(String name)
```
 Get the comma delimited values of the name property as a collection of Strings. If no such property is specified then empty collection is returned.
 This is an optimized version of getStrings(String)
 
 Parameters:
 name - property name.
 
 Returns:
 property value as a collection of Strings.
 - getStrings
```
public String[] getStrings(String name)
```
 Get the comma delimited values of the name property as an array of Strings. If no such property is specified then null is returned.
 
 Parameters:
 name - property name.
 
 Returns:
 property value as an array of Strings, or null.
 - getStrings
```
public String[] getStrings(String name,
 String... defaultValue)
```
 Get the comma delimited values of the name property as an array of Strings. If no such property is specified then default value is returned.
 
 Parameters:
 name - property name.
 defaultValue - The default value
 
 Returns:
 property value as an array of Strings, or default value.
 - getTrimmedStringCollection
```
public Collection<String> getTrimmedStringCollection(String name)
```
 Get the comma delimited values of the name property as a collection of Strings, trimmed of the leading and trailing whitespace. If no such property is specified then empty Collection is returned.
 
 Parameters:
 name - property name.
 
 Returns:
 property value as a collection of Strings, or empty Collection
 - getTrimmedStrings
```
public String[] getTrimmedStrings(String name)
```
 Get the comma delimited values of the name property as an array of Strings, trimmed of the leading and trailing whitespace. If no such property is specified then an empty array is returned.
 
 Parameters:
 name - property name.
 
 Returns:
 property value as an array of trimmed Strings, or empty array.
 - getTrimmedStrings
```
public String[] getTrimmedStrings(String name,
 String... defaultValue)
```
 Get the comma delimited values of the name property as an array of Strings, trimmed of the leading and trailing whitespace. If no such property is specified then default value is returned.
 
 Parameters:
 name - property name.
 defaultValue - The default value
 
 Returns:
 property value as an array of trimmed Strings, or default value.
 - setStrings
```
public void setStrings(String name,
 String... values)
```
 Set the array of string values for the name property as as comma delimited values.
 
 Parameters:
 name - property name.
 values - The values
 - getSocketAddr
```
public InetSocketAddress getSocketAddr(String name,
 String defaultAddress,
 int defaultPort)
```
 Get the socket address for name property as a InetSocketAddress.
 
 Parameters:
 name - property name.
 defaultAddress - the default value
 defaultPort - the default port
 
 Returns:
 InetSocketAddress
 - setSocketAddr
```
public void setSocketAddr(String name,
 InetSocketAddress addr)
```
 Set the socket address for the name property as a host:port.
 - updateConnectAddr
```
public InetSocketAddress updateConnectAddr(String name,
 InetSocketAddress addr)
```
 Set the socket address a client can use to connect for the name property as a host:port. The wildcard address is replaced with the local host's address.
 
 Parameters:
 name - property name.
 addr - InetSocketAddress of a listener to store in the given property
 
 Returns:
 InetSocketAddress for clients to connect
 - getClassByName
```
public Class<?> getClassByName(String name)
 throws ClassNotFoundException
```
 Load a class by name.
 
 Parameters:
 name - the class name.
 
 Returns:
 the class object.
 
 Throws:
 
 ClassNotFoundException - if the class is not found.
 - getClassByNameOrNull
```
public Class<?> getClassByNameOrNull(String name)
```
 Load a class by name, returning null rather than throwing an exception if it couldn't be loaded. This is to avoid the overhead of creating an exception.
 
 Parameters:
 name - the class name
 
 Returns:
 the class object, or null if it could not be found.
 - getClasses
```
public Class<?>[] getClasses(String name,
 Class<?>... defaultValue)
```
 Get the value of the name property as an array of Class. The value of the property specifies a list of comma separated class names. If no such property is specified, then defaultValue is returned.
 
 Parameters:
 name - the property name.
 defaultValue - default value.
 
 Returns:
 property value as a Class[], or defaultValue.
 - getClass
```
public Class<?> getClass(String name,
 Class<?> defaultValue)
```
 Get the value of the name property as a Class. If no such property is specified, then defaultValue is returned.
 
 Parameters:
 name - the class name.
 defaultValue - default value.
 
 Returns:
 property value as a Class, or defaultValue.
 - getClass
```
public  Class<? extends U> getClass(String name,
 Class<? extends U> defaultValue,
 Class xface)
```
 Get the value of the name property as a Class implementing the interface specified by xface. If no such property is specified, then defaultValue is returned. An exception is thrown if the returned class does not implement the named interface.
 
 Parameters:
 name - the class name.
 defaultValue - default value.
 xface - the interface implemented by the named class.
 
 Returns:
 property value as a Class, or defaultValue.
 - getInstances
```
public  List getInstances(String name,
 Class xface)
```
 Get the value of the name property as a List of objects implementing the interface specified by xface. An exception is thrown if any of the classes does not exist, or if it does not implement the named interface.
 
 Parameters:
 name - the property name.
 xface - the interface implemented by the classes named by name.
 
 Returns:
 a List of objects implementing xface.
 - setClass
```
public void setClass(String name,
 Class<?> theClass,
 Class<?> xface)
```
 Set the value of the name property to the name of a theClass implementing the given interface xface. An exception is thrown if theClass does not implement the interface xface.
 
 Parameters:
 name - property name.
 theClass - property value.
 xface - the interface implemented by the named class.
 - getLocalPath
```
public Path getLocalPath(String dirsProp,
 String path)
 throws IOException
```
 Get a local file under a directory named by dirsProp with the given path. If dirsProp contains multiple directories, then one is chosen based on path's hash code. If the selected directory does not exist, an attempt is made to create it.
 
 Parameters:
 dirsProp - directory in which to locate the file.
 path - file-path.
 
 Returns:
 local file under the directory with the given path.
 
 Throws:
 
 IOException
 - getFile
```
public File getFile(String dirsProp,
 String path)
 throws IOException
```
 Get a local file name under a directory named in dirsProp with the given path. If dirsProp contains multiple directories, then one is chosen based on path's hash code. If the selected directory does not exist, an attempt is made to create it.
 
 Parameters:
 dirsProp - directory in which to locate the file.
 path - file-path.
 
 Returns:
 local file under the directory with the given path.
 
 Throws:
 
 IOException
 - getResource
```
public URL getResource(String name)
```
 Get the URL for the named resource.
 
 Parameters:
 name - resource name.
 
 Returns:
 the url for the named resource.
 - getConfResourceAsInputStream
```
public InputStream getConfResourceAsInputStream(String name)
```
 Get an input stream attached to the configuration resource with the given name.
 
 Parameters:
 name - configuration resource name.
 
 Returns:
 an input stream attached to the resource.
 - getConfResourceAsReader
```
public Reader getConfResourceAsReader(String name)
```
 Get a Reader attached to the configuration resource with the given name.
 
 Parameters:
 name - configuration resource name.
 
 Returns:
 a reader attached to the resource.
 - getFinalParameters
```
public Set<String> getFinalParameters()
```
 Get the set of parameters marked final.
 
 Returns:
 final parameter set.
 - getProps
```
protected Properties getProps()
```
 - size
```
public int size()
```
 Return the number of keys in the configuration.
 
 Returns:
 number of keys in the configuration.
 - clear
```
public void clear()
```
 Clears all keys from the configuration.
 - iterator
```
public Iterator<Map.Entry<String,String>> iterator()
```
 Get an Iterator to go through the list of String key-value pairs in the configuration.
 
 Specified by:
 
 iterator in interface Iterable<Map.Entry<String,String>>
 
 Returns:
 an iterator over the entries.
 - writeXml
```
public void writeXml(OutputStream out)
 throws IOException
```
 Write out the non-default properties in this configuration to the given OutputStream.
 
 Parameters:
 out - the output stream to write to.
 
 Throws:
 
 IOException
 - writeXml
```
public void writeXml(Writer out)
 throws IOException
```
 Write out the non-default properties in this configuration to the given Writer.
 
 Parameters:
 out - the writer to write to.
 
 Throws:
 
 IOException
 - dumpConfiguration
```
public static void dumpConfiguration(Configuration config,
 Writer out)
 throws IOException
```
 Writes out all the parameters and their properties (final and resource) to the given Writer The format of the output would be { "properties" : [ {key1,value1,key1.isFinal,key1.resource}, {key2,value2, key2.isFinal,key2.resource}... ] } It does not output the parameters of the configuration object which is loaded from an input stream.
 
 Parameters:
 out - the Writer to write to
 
 Throws:
 
 IOException
 - getClassLoader
```
public ClassLoader getClassLoader()
```
 Get the ClassLoader for this job.
 
 Returns:
 the correct class loader.
 - setClassLoader
```
public void setClassLoader(ClassLoader classLoader)
```
 Set the class loader that will be used to load the various objects.
 
 Parameters:
 classLoader - the new class loader.
 - toString
```
public String toString()
```
 Overrides:
 
 toString in class Object
 - setQuietMode
```
public void setQuietMode(boolean quietmode)
```
 Set the quietness-mode. In the quiet-mode, error and informational messages might not be logged.
 
 Parameters:
 quietmode - true to set quiet-mode on, false to turn it off.
 - main
```
public static void main(String[] args)
 throws Exception
```
 For debugging. List non-default properties to the terminal and exit.
 
 Throws:
 
 Exception
 - readFields
```
public void readFields(DataInput in)
 throws IOException
```
 Description copied from interface: Writable
 
 Deserialize the fields of this object from in.
 For efficiency, implementations should attempt to re-use storage in the existing object where possible.
 
 Specified by:
 
 readFields in interface Writable
 
 Parameters:
 in - DataInput to deseriablize this object from.
 
 Throws:
 
 IOException
 - write
```
public void write(DataOutput out)
 throws IOException
```
 Description copied from interface: Writable
 
 Serialize the fields of this object to out.
 
 Specified by:
 
 write in interface Writable
 
 Parameters:
 out - DataOuput to serialize this object into.
 
 Throws:
 
 IOException
 - getValByRegex
```
public Map<String,String> getValByRegex(String regex)
```
 get keys matching the the regex
 
 Parameters:
 regex -
 
 Returns:
 Map with matching keys

Class Configuration

Resources

Final Parameters

Variable Expansion

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Configuration

Configuration

Configuration

Method Detail

addDeprecation

addDeprecation

addDeprecation

addDeprecation

isDeprecated

addDefaultResource

addResource

addResource

addResource

addResource

addResource

reloadConfiguration

get

getTrimmed

getRaw

set

set

unset

setIfUnset

get

getInt

setInt

getLong

getLongBytes

setLong

getFloat

setFloat

getBoolean

setBoolean

setBooleanIfUnset

setEnum

getEnum

getPattern

setPattern

getPropertySources

getRange

getStringCollection

getStrings

getStrings

getTrimmedStringCollection

getTrimmedStrings

getTrimmedStrings

setStrings

getSocketAddr

setSocketAddr

updateConnectAddr

getClassByName

getClassByNameOrNull

getClasses

getClass

getClass

getInstances

setClass

getLocalPath

getFile

getResource

getConfResourceAsInputStream

getConfResourceAsReader

getFinalParameters

getProps

size

clear

iterator

writeXml

writeXml

dumpConfiguration

getClassLoader

setClassLoader