Class EnvVariables


  • public class EnvVariables
    extends Object
    A simple class offering static access to environmental variables.
    Author:
    Michael Röder (michael.roeder@uni-paderborn.de)
    • Constructor Summary

      Constructors 
      Constructor Description
      EnvVariables()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static boolean getBoolean​(String name)
      Returns the value of the environmental variable with the given name as boolean or throws an IllegalStateException if the variable can not be found or an error occurs.
      static boolean getBoolean​(String name, boolean defaultValue)
      Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
      static boolean getBoolean​(String name, boolean defaultValue, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
      static boolean getBoolean​(String name, Supplier<Boolean> defaultValueFactory)
      Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
      static boolean getBoolean​(String name, Supplier<Boolean> defaultValueFactory, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
      static boolean getBoolean​(String name, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as boolean or throws an IllegalStateException if the variable can not be found or an error occurs.
      protected static boolean getBooleanValue​(String name, boolean defaultValue, org.slf4j.Logger logger, boolean exceptionWhenFailing, boolean hasDefaultValue)
      Internal method defining the default value factory function before calling getBooleanValue(String, Supplier, Logger, boolean).
      protected static boolean getBooleanValue​(String name, Supplier<Boolean> defaultValueFactory, org.slf4j.Logger logger, boolean exceptionWhenFailing)
      Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
      static int getInt​(String name)
      Returns the value of the environmental variable with the given name as int or throws an IllegalStateException if the variable can not be found or an error occurs.
      static int getInt​(String name, int defaultValue)
      Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
      static int getInt​(String name, int defaultValue, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
      static int getInt​(String name, Supplier<Integer> defaultValueFactory)
      Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
      static int getInt​(String name, Supplier<Integer> defaultValueFactory, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
      static int getInt​(String name, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as int or throws an IllegalStateException if the variable can not be found or an error occurs.
      protected static int getIntValue​(String name, int defaultValue, org.slf4j.Logger logger, boolean exceptionWhenFailing, boolean hasDefaultValue)
      Internal method defining the default value factory function before calling getIntValue(String, Supplier, Logger, boolean).
      protected static int getIntValue​(String name, Supplier<Integer> defaultValueFactory, org.slf4j.Logger logger, boolean exceptionWhenFailing)
      Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
      static org.apache.jena.rdf.model.Model getModel​(String name)
      Returns the value of the environmental variable with the given name as Model or throws an IllegalStateException if the variable can not be found or an error occurs.
      static org.apache.jena.rdf.model.Model getModel​(String name, Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory)
      Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
      static org.apache.jena.rdf.model.Model getModel​(String name, Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
      static org.apache.jena.rdf.model.Model getModel​(String name, org.apache.jena.rdf.model.Model defaultValue)
      Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
      static org.apache.jena.rdf.model.Model getModel​(String name, org.apache.jena.rdf.model.Model defaultValue, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
      static org.apache.jena.rdf.model.Model getModel​(String name, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as Model or throws an IllegalStateException if the variable can not be found or an error occurs.
      protected static org.apache.jena.rdf.model.Model getModelValue​(String name, Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory, org.slf4j.Logger logger, boolean exceptionWhenFailing)
      Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
      protected static org.apache.jena.rdf.model.Model getModelValue​(String name, org.apache.jena.rdf.model.Model defaultValue, org.slf4j.Logger logger, boolean exceptionWhenFailing, boolean hasDefaultValue)
      Internal method defining the default value factory function before calling getModelValue(String, Supplier, Logger, boolean).
      static String getString​(String name)
      Returns the value of the environmental variable with the given name as String or throws an IllegalStateException if the variable can not be found or an error occurs.
      static String getString​(String name, String defaultValue)
      Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
      static String getString​(String name, String defaultValue, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
      static String getString​(String name, Supplier<String> defaultValueFactory)
      Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
      static String getString​(String name, Supplier<String> defaultValueFactory, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
      static String getString​(String name, org.slf4j.Logger logger)
      Returns the value of the environmental variable with the given name as String or throws an IllegalStateException if the variable can not be found or an error occurs.
      protected static String getStringValue​(String name, String defaultValue, org.slf4j.Logger logger, boolean exceptionWhenFailing, boolean hasDefaultValue)
      Internal method defining the default value factory function before calling getStringValue(String, Supplier, Logger, boolean).
      protected static String getStringValue​(String name, Supplier<String> defaultValueFactory, org.slf4j.Logger logger, boolean exceptionWhenFailing)
      Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
      protected static <T> T getVariableValue​(String name, Function<String,​T> conversion, Supplier<T> defaultValueFactory, org.slf4j.Logger logger, boolean exceptionWhenFailing)
      Generic method for accessing an environmental variable which has the given name and will be transformed into the return type using the given conversion function.
    • Constructor Detail

      • EnvVariables

        public EnvVariables()
    • Method Detail

      • getVariableValue

        protected static <T> T getVariableValue​(String name,
                                                Function<String,​T> conversion,
                                                Supplier<T> defaultValueFactory,
                                                org.slf4j.Logger logger,
                                                boolean exceptionWhenFailing)
                                         throws IllegalStateException
        Generic method for accessing an environmental variable which has the given name and will be transformed into the return type using the given conversion function. The behavior in case of an error is defined by the given default value and Logger objects. If a problem occurs and a Logger is available, the error will be logged using the Logger.error(String) method. If exceptionWhenFailing is set to true an IllegalStateException is thrown. Else, if a defaultValueFactory is available, a default value will be returned. Otherwise null is returned.
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getString

        public static String getString​(String name)
                                throws IllegalStateException
        Returns the value of the environmental variable with the given name as String or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getString

        public static String getString​(String name,
                                       String defaultValue)
        Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getString

        public static String getString​(String name,
                                       Supplier<String> defaultValueFactory)
        Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getString

        public static String getString​(String name,
                                       org.slf4j.Logger logger)
                                throws IllegalStateException
        Returns the value of the environmental variable with the given name as String or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getString

        public static String getString​(String name,
                                       String defaultValue,
                                       org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getString

        public static String getString​(String name,
                                       Supplier<String> defaultValueFactory,
                                       org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as String or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getStringValue

        protected static String getStringValue​(String name,
                                               String defaultValue,
                                               org.slf4j.Logger logger,
                                               boolean exceptionWhenFailing,
                                               boolean hasDefaultValue)
                                        throws IllegalStateException
        Internal method defining the default value factory function before calling getStringValue(String, Supplier, Logger, boolean).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        hasDefaultValue - flag indicating whether a default value has been provided.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getStringValue

        protected static String getStringValue​(String name,
                                               Supplier<String> defaultValueFactory,
                                               org.slf4j.Logger logger,
                                               boolean exceptionWhenFailing)
                                        throws IllegalStateException
        Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name)
                                                        throws IllegalStateException
        Returns the value of the environmental variable with the given name as Model or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name,
                                                               org.apache.jena.rdf.model.Model defaultValue)
        Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name,
                                                               Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory)
        Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name,
                                                               org.slf4j.Logger logger)
                                                        throws IllegalStateException
        Returns the value of the environmental variable with the given name as Model or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name,
                                                               org.apache.jena.rdf.model.Model defaultValue,
                                                               org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getModel

        public static org.apache.jena.rdf.model.Model getModel​(String name,
                                                               Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory,
                                                               org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as Model or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getModelValue

        protected static org.apache.jena.rdf.model.Model getModelValue​(String name,
                                                                       org.apache.jena.rdf.model.Model defaultValue,
                                                                       org.slf4j.Logger logger,
                                                                       boolean exceptionWhenFailing,
                                                                       boolean hasDefaultValue)
                                                                throws IllegalStateException
        Internal method defining the default value factory function before calling getModelValue(String, Supplier, Logger, boolean).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        hasDefaultValue - flag indicating whether a default value has been provided.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getModelValue

        protected static org.apache.jena.rdf.model.Model getModelValue​(String name,
                                                                       Supplier<org.apache.jena.rdf.model.Model> defaultValueFactory,
                                                                       org.slf4j.Logger logger,
                                                                       boolean exceptionWhenFailing)
                                                                throws IllegalStateException
        Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getInt

        public static int getInt​(String name)
                          throws IllegalStateException
        Returns the value of the environmental variable with the given name as int or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getInt

        public static int getInt​(String name,
                                 int defaultValue)
        Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getInt

        public static int getInt​(String name,
                                 Supplier<Integer> defaultValueFactory)
        Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getInt

        public static int getInt​(String name,
                                 org.slf4j.Logger logger)
                          throws IllegalStateException
        Returns the value of the environmental variable with the given name as int or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getInt

        public static int getInt​(String name,
                                 int defaultValue,
                                 org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getInt

        public static int getInt​(String name,
                                 Supplier<Integer> defaultValueFactory,
                                 org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as int or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getIntValue

        protected static int getIntValue​(String name,
                                         int defaultValue,
                                         org.slf4j.Logger logger,
                                         boolean exceptionWhenFailing,
                                         boolean hasDefaultValue)
                                  throws IllegalStateException
        Internal method defining the default value factory function before calling getIntValue(String, Supplier, Logger, boolean).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        hasDefaultValue - flag indicating whether a default value has been provided.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getIntValue

        protected static int getIntValue​(String name,
                                         Supplier<Integer> defaultValueFactory,
                                         org.slf4j.Logger logger,
                                         boolean exceptionWhenFailing)
                                  throws IllegalStateException
        Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getBoolean

        public static boolean getBoolean​(String name)
                                  throws IllegalStateException
        Returns the value of the environmental variable with the given name as boolean or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getBoolean

        public static boolean getBoolean​(String name,
                                         boolean defaultValue)
        Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getBoolean

        public static boolean getBoolean​(String name,
                                         Supplier<Boolean> defaultValueFactory)
        Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getBoolean

        public static boolean getBoolean​(String name,
                                         org.slf4j.Logger logger)
                                  throws IllegalStateException
        Returns the value of the environmental variable with the given name as boolean or throws an IllegalStateException if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value
        Throws:
        IllegalStateException - if the variable can not be found or an error occurs.
      • getBoolean

        public static boolean getBoolean​(String name,
                                         boolean defaultValue,
                                         org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getBoolean

        public static boolean getBoolean​(String name,
                                         Supplier<Boolean> defaultValueFactory,
                                         org.slf4j.Logger logger)
        Returns the value of the environmental variable with the given name as boolean or the default value if the variable can not be found or an error occurs.
        Parameters:
        name - name of the environmental variable which should be accessed
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        Returns:
        the variable value or the default value if an error occurred and a default value is available.
      • getBooleanValue

        protected static boolean getBooleanValue​(String name,
                                                 boolean defaultValue,
                                                 org.slf4j.Logger logger,
                                                 boolean exceptionWhenFailing,
                                                 boolean hasDefaultValue)
                                          throws IllegalStateException
        Internal method defining the default value factory function before calling getBooleanValue(String, Supplier, Logger, boolean).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValue - the default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        hasDefaultValue - flag indicating whether a default value has been provided.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.
      • getBooleanValue

        protected static boolean getBooleanValue​(String name,
                                                 Supplier<Boolean> defaultValueFactory,
                                                 org.slf4j.Logger logger,
                                                 boolean exceptionWhenFailing)
                                          throws IllegalStateException
        Internal method defining the conversion function before calling #getVariableValue(String, Function, Object, Logger).
        Parameters:
        name - name of the environmental variable which should be accessed
        conversion - the function which is used to convert the String of the variable value into the expected value type. It is assumed that this function will throw an exception if an error occurs.
        defaultValueFactory - A factory method which can be used to generate a default value which will be returned if the variable can not be found or if an error occurs.
        logger - the Logger which will be used to log errors if they occur.
        exceptionWhenFailing - flag indicating whether an exception should be thrown if an error occurs.
        Returns:
        the variable value converted to the expected value or the default value if an error occurred and a default value is available.
        Throws:
        IllegalStateException - if exceptionWhenFailing is set to true and one of the following two errors occurs: 1) the variable is not available or 2) the conversion function throws an exception.