Class Configuration
Stores runtime configuration information for application parameters that may
vary on restarting. This implements the Singleton pattern, but through static
methods. That is, the first time Configuration is used, the properties are
loaded into the Singleton instance. Subsequent calls to valueFor() retrieve
values from the Singleton. To look up a property, use
valueFor(String)
.
Properties may be overridden using a second properties file, or individually using System properties specified on the command line. To override using a second properties file, specify the System property xr-conf. This should be the location of the second file relative to the CLASSPATH, or else a file path, e.g.
java -Dxr-conf=resources/conf/myprops.conf
You can also place your override properties file in your user home directory, in
${user.home}/.flyingsaucer/local.xhtmlrenderer.conf
To override a property using the System properties, just re-define the property on the command line. e.g.
java -Dxr.property-name=new_value
The order in which these will be read is: default properties (bundled with the core, in the jar; override configuration properties; properties file in user.home; and system properties.
You can override as many properties as you like.
Note that overrides are driven by the property names in the default configuration file. Specifying a property name not in that file will have no effect--the property will not be loaded or available for lookup. Configuration is NOT used to control logging levels or output; see LogStartupConfig.
There are convenience converstion method for all the primitive types, in
methods like valueAsInt(String, int)
. A default must always be provided for these
methods. The default is returned if the value is not found, or if the
conversion from String fails. If the value is not present, or the conversion
fails, a warning message is written to the log.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate Logger
Logger we use internally related to configuration.private Level
The log Level for Configuration messages; taken from show-config System property.private Properties
Our backing data store of properties.private static final String
The location of our default properties file; must be on the CLASSPATH.private static Configuration
The Singleton instance of the class.List of LogRecords for messages from Configuration startup; used to hold these temporarily as we can't use XRLog while starting up, as it depends on Configuration. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate void
Used internally to log a message about the class at level FINEprivate void
Used internally to log a message about the class at level FINERprivate String
private String
private void
static boolean
private void
Used internally to log a message about the class at level INFOprivate static Configuration
instance()
static boolean
Returns true if the value is not "true" (ignores case), or the default provided value if not found or if the value is not a valid boolean (true or false, ignores case).static boolean
Returns true if the value is "true" (ignores case), or the default provided value if not found or if the value is not a valid boolean (true or false, ignores case).keysByPrefix
(String prefix) Returns all configuration keys that start with prefix.private void
Loads the default set of properties.private void
Loads overriding property values from a second configuration file; this is optional.private void
Loads overriding property values from a System properties; this is optional.private void
Writes a log of loaded properties to the plumbing.init Logger.private Properties
Returns a Properties instance filled with values of last resort--in case we can't read default properties file for some reason; this is to prevent Configuration init from throwing any exceptions, or ending up with a completely empty configuration instance.private void
Used internally for logging status/info about the class.static void
setConfigLogger
(Logger logger) Sets the logger which we use for Configuration-related logging.static int
valueAsByte
(String key, byte defaultVal) Returns the value for key in the Configuration as a byte, or the default provided value if not found or if the value is not a valid byte.static double
valueAsDouble
(String key, double defaultVal) Returns the value for key in the Configuration as a double, or the default provided value if not found or if the value is not a valid double.static float
valueAsFloat
(String key, float defaultVal) Returns the value for key in the Configuration as a float, or the default provided value if not found or if the value is not a valid float.static int
valueAsInt
(String key, int defaultVal) Returns the value for key in the Configuration as an integer, or a default value if not found or if the value is not a valid integer.static long
valueAsLong
(String key, long defaultVal) Returns the value for key in the Configurationas a long, or the default provided value if not found or if the value is not a valid long.static int
valueAsShort
(String key, short defaultVal) Returns the value for key in the Configuration as a short, or the default provided value if not found or if the value is not a valid short.static String
Returns the value for key in the Configuration.static String
Returns the value for key in the Configuration, or the default provided value if not found.static Object
valueFromClassConstant
(String key, Object defaultValue) Given a property, resolves the value to a public constant field on some class, where the field is of type Object.private void
Used internally to log a message about the class at level WARNINGprivate void
Used internally to log a message about the class at level WARNING, in case an exception was thrown
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Field Details
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properties
Our backing data store of properties. -
logLevel
The log Level for Configuration messages; taken from show-config System property. -
sInstance
The Singleton instance of the class. -
startupLogRecords
List of LogRecords for messages from Configuration startup; used to hold these temporarily as we can't use XRLog while starting up, as it depends on Configuration. -
configLogger
Logger we use internally related to configuration. -
SF_FILE_NAME
The location of our default properties file; must be on the CLASSPATH.- See Also:
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Constructor Details
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Configuration
private Configuration()Default constructor. Will parse default configuration file, system properties, override properties, etc. and result in a usable Configuration instance.- Throws:
RuntimeException
- if any stage of loading configuration results in an Exception. This could happen, for example, if the default configuration file was not readable.
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Method Details
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handleUnexpectedExceptionOnInit
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setConfigLogger
Sets the logger which we use for Configuration-related logging. Before this is called the first time, all internal log records are queued up; they are flushed to the logger when this method is first called. Afterwards, all log events are written to this logger. This queueing behavior helps avoid order-of-operations bugs related to loading configuration information related to logging.- Parameters:
logger
- Logger used for Configuration-related messages
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println
Used internally for logging status/info about the class.- Parameters:
level
- the logging level to record the message atmsg
- the message to log
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info
Used internally to log a message about the class at level INFO- Parameters:
msg
- message to log
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warning
Used internally to log a message about the class at level WARNING- Parameters:
msg
- message to log
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warning
Used internally to log a message about the class at level WARNING, in case an exception was thrown- Parameters:
msg
- message to logth
- the exception to report
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fine
Used internally to log a message about the class at level FINE- Parameters:
msg
- message to log
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finer
Used internally to log a message about the class at level FINER- Parameters:
msg
- message to log
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loadDefaultProperties
private void loadDefaultProperties()Loads the default set of properties. -
loadOverrideProperties
Loads overriding property values from a second configuration file; this is optional. See class documentation.- Parameters:
uri
- Path to the file, or classpath URL, where properties are defined.
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getSystemPropertyOverrideFileName
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getUserHomeOverrideFileName
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loadSystemProperties
private void loadSystemProperties()Loads overriding property values from a System properties; this is optional. See class documentation. -
logAfterLoad
private void logAfterLoad()Writes a log of loaded properties to the plumbing.init Logger. -
valueFor
Returns the value for key in the Configuration. A warning is issued to the log if the property is not defined.- Parameters:
key
- Name of the property.- Returns:
- Value assigned to the key, as a String.
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hasValue
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valueAsByte
Returns the value for key in the Configuration as a byte, or the default provided value if not found or if the value is not a valid byte. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueAsShort
Returns the value for key in the Configuration as a short, or the default provided value if not found or if the value is not a valid short. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueAsInt
Returns the value for key in the Configuration as an integer, or a default value if not found or if the value is not a valid integer. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueAsLong
Returns the value for key in the Configurationas a long, or the default provided value if not found or if the value is not a valid long. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueAsFloat
Returns the value for key in the Configuration as a float, or the default provided value if not found or if the value is not a valid float. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueAsDouble
Returns the value for key in the Configuration as a double, or the default provided value if not found or if the value is not a valid double. A warning is issued to the log if the property is not defined, or if the conversion from String fails.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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valueFor
Returns the value for key in the Configuration, or the default provided value if not found. A warning is issued to the log if the property is not defined, and if the default is null.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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keysByPrefix
Returns all configuration keys that start with prefix. Iterator will be empty if no such keys are found.- Parameters:
prefix
- Prefix to filter on. No regex.- Returns:
- Returns Iterator, see description.
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isTrue
Returns true if the value is "true" (ignores case), or the default provided value if not found or if the value is not a valid boolean (true or false, ignores case). A warning is issued to the log if the property is not defined, and if the default is null.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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isFalse
Returns true if the value is not "true" (ignores case), or the default provided value if not found or if the value is not a valid boolean (true or false, ignores case). A warning is issued to the log if the property is not defined, or the value is not a valid boolean.- Parameters:
key
- Name of the property.defaultVal
- PARAM- Returns:
- Value assigned to the key, as a String.
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instance
- Returns:
- The singleton instance of the class.
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valueFromClassConstant
Given a property, resolves the value to a public constant field on some class, where the field is of type Object. The property value must the the FQN of the class and field, e.g. aKey=java.awt.RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR will return the value of the VALUE_INTERPOLATION_NEAREST_NEIGHBOR constant on the RendingHints class.- Parameters:
key
- Name of the propertydefaultValue
- Returned in case of error.- Returns:
- Value of the constant, or defaultValue in case of error.
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newFallbackProperties
Returns a Properties instance filled with values of last resort--in case we can't read default properties file for some reason; this is to prevent Configuration init from throwing any exceptions, or ending up with a completely empty configuration instance.
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