Package com.openhtmltopdf.util

Class Configuration

  • public class Configuration
extends java.lang.Object

    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.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.logging.Logger configLogger
      Logger we use internally related to configuration.
      private java.util.logging.Level logLevel
      The log Level for Configuration messages; taken from show-config System property.
      private java.util.Properties properties
      Our backing data store of properties.
      private static java.lang.String SF_FILE_NAME
      The location of our default properties file; must be on the CLASSPATH.
      private static Configuration sInstance
      The Singleton instance of the class.
      private java.util.List<java.util.logging.LogRecord> 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.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private Configuration()
      Default constructor.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private void fine​(java.lang.String msg)
      Used internally to log a message about the class at level FINE
      private void finer​(java.lang.String msg)
      Used internally to log a message about the class at level FINER
      private java.lang.String getSystemPropertyOverrideFileName()  
      private java.lang.String getUserHomeOverrideFileName()  
      private void handleUnexpectedExceptionOnInit​(java.lang.Exception e)  
      static boolean hasValue​(java.lang.String key)  
      private void info​(java.lang.String msg)
      Used internally to log a message about the class at level INFO
      private static Configuration instance()  
      static boolean isFalse​(java.lang.String key, boolean defaultVal)
      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 isTrue​(java.lang.String key, boolean defaultVal)
      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).
      static java.util.Iterator<java.lang.String> keysByPrefix​(java.lang.String prefix)
      Returns all configuration keys that start with prefix.
      private void loadDefaultProperties()
      Loads the default set of properties.
      private void loadOverrideProperties​(java.lang.String uri)
      Loads overriding property values from a second configuration file; this is optional.
      private void loadSystemProperties()
      Loads overriding property values from a System properties; this is optional.
      private void logAfterLoad()
      Writes a log of loaded properties to the plumbing.init Logger.
      private java.util.Properties 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.
      private void println​(java.util.logging.Level level, java.lang.String msg)
      Used internally for logging status/info about the class.
      static void setConfigLogger​(java.util.logging.Logger logger)
      Sets the logger which we use for Configuration-related logging.
      static int valueAsByte​(java.lang.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​(java.lang.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​(java.lang.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​(java.lang.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​(java.lang.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​(java.lang.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 java.lang.String valueFor​(java.lang.String key)
      Returns the value for key in the Configuration.
      static java.lang.String valueFor​(java.lang.String key, java.lang.String defaultVal)
      Returns the value for key in the Configuration, or the default provided value if not found.
      static java.lang.Object valueFromClassConstant​(java.lang.String key, java.lang.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 warning​(java.lang.String msg)
      Used internally to log a message about the class at level WARNING
      private void warning​(java.lang.String msg, java.lang.Throwable th)
      Used internally to log a message about the class at level WARNING, in case an exception was thrown

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • properties

        private java.util.Properties properties
        Our backing data store of properties.

      • logLevel

        private java.util.logging.Level logLevel
        The log Level for Configuration messages; taken from show-config System property.

      • sInstance

        private static Configuration sInstance
        The Singleton instance of the class.

      • startupLogRecords

        private java.util.List<java.util.logging.LogRecord> 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

        private java.util.logging.Logger configLogger
        Logger we use internally related to configuration.

      • SF_FILE_NAME

        private static final java.lang.String SF_FILE_NAME
        The location of our default properties file; must be on the CLASSPATH.
        See Also:
        Constant Field Values

    • Constructor Detail

      • Configuration

        private Configuration()
        Default constructor. Will parse default configuration file, system properties, override properties, etc. and result in a usable Configuration instance.
        Throws:
        java.lang.RuntimeException - if any stage of loading configuration results in an Exception. This could happen, for example, if the default configuration file was not readable.

    • Method Detail

      • handleUnexpectedExceptionOnInit

        private void handleUnexpectedExceptionOnInit​(java.lang.Exception e)

      • setConfigLogger

        public static void setConfigLogger​(java.util.logging.Logger logger)
        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

      • println

        private void println​(java.util.logging.Level level,
                     java.lang.String msg)
        Used internally for logging status/info about the class.
        Parameters:
        level - the logging level to record the message at
        msg - the message to log

      • info

        private void info​(java.lang.String msg)
        Used internally to log a message about the class at level INFO
        Parameters:
        msg - message to log

      • warning

        private void warning​(java.lang.String msg)
        Used internally to log a message about the class at level WARNING
        Parameters:
        msg - message to log

      • warning

        private void warning​(java.lang.String msg,
                     java.lang.Throwable th)
        Used internally to log a message about the class at level WARNING, in case an exception was thrown
        Parameters:
        msg - message to log
        th - the exception to report

      • fine

        private void fine​(java.lang.String msg)
        Used internally to log a message about the class at level FINE
        Parameters:
        msg - message to log

      • finer

        private void finer​(java.lang.String msg)
        Used internally to log a message about the class at level FINER
        Parameters:
        msg - message to log

      • loadDefaultProperties

        private void loadDefaultProperties()
        Loads the default set of properties.

      • loadOverrideProperties

        private void loadOverrideProperties​(java.lang.String uri)
        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.

      • getSystemPropertyOverrideFileName

        private java.lang.String getSystemPropertyOverrideFileName()

      • getUserHomeOverrideFileName

        private java.lang.String getUserHomeOverrideFileName()

      • 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

        public static java.lang.String valueFor​(java.lang.String key)
        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.

      • hasValue

        public static boolean hasValue​(java.lang.String key)

      • valueAsByte

        public static int valueAsByte​(java.lang.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. 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.

      • valueAsShort

        public static int valueAsShort​(java.lang.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. 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.

      • valueAsInt

        public static int valueAsInt​(java.lang.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. 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.

      • valueAsLong

        public static long valueAsLong​(java.lang.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. 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.

      • valueAsFloat

        public static float valueAsFloat​(java.lang.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. 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.

      • valueAsDouble

        public static double valueAsDouble​(java.lang.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. 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.

      • valueFor

        public static java.lang.String valueFor​(java.lang.String key,
                                        java.lang.String defaultVal)
        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.

      • keysByPrefix

        public static java.util.Iterator<java.lang.String> keysByPrefix​(java.lang.String prefix)
        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.

      • isTrue

        public static boolean isTrue​(java.lang.String key,
                             boolean defaultVal)
        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.

      • isFalse

        public static boolean isFalse​(java.lang.String key,
                              boolean defaultVal)
        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.

      • instance

        private static Configuration instance()
        Returns:
        The singleton instance of the class.

      • valueFromClassConstant

        public static java.lang.Object valueFromClassConstant​(java.lang.String key,
                                                      java.lang.Object defaultValue)
        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 property
        defaultValue - Returned in case of error.
        Returns:
        Value of the constant, or defaultValue in case of error.

      • newFallbackProperties

        private java.util.Properties 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.