org.jminor.common

Class PropertyStore

java.lang.Object

org.jminor.common.PropertyStore

public final class PropertyStore
extends java.lang.Object

Provides configuration values which sync with a central configuration store as well as system properties, which can be written to file. Initial values parsed from a configuration file are overridden by system properties. If values are not found in the configuration file or in system properties the default value is used.

 File configurationFile = new File(System.getProperty("user.home") + "/app.properties");

 PropertyStore store = new PropertyStore(configurationFile);

 Value<Boolean> featureEnabled = store.propertyValue("feature.enabled", false);
 Value<String> defaultUsername = store.propertyValue("default.username", System.getProperty("user.name"));

 featureEnabled.set(true);
 defaultUsername.set("scott");

 store.writeToFile(configurationFile);
 

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	VALUE_SEPARATOR The separator used to separate multiple values.

Constructor Summary

Constructors

Constructor and Description
PropertyStore(java.io.File propertiesFile) Instantiates a new PropertyStore backed by the given file.
PropertyStore(java.util.Properties properties) Instantiates a new PropertyStore initialized with the given properties.

Method Summary

Modifier and Type	Method and Description
boolean	containsProperty(java.lang.String property) Returns true if this PropertyStore contains a value for the given property
java.util.List<java.lang.String>	getProperties(java.lang.String prefix) Returns the values associated with the properties with the given prefix
java.lang.String	getProperty(java.lang.String property) Retrieves the value for the given property, null if no value is present
java.util.List<java.lang.String>	getPropertyNames(java.lang.String prefix) Returns all property names with the given prefix
<V> PropertyValue<V>	getPropertyValue(java.lang.String property) Returns the Value associated with the given property, null if none has been created.
<V> PropertyValue<java.util.List<V>>	propertyListValue(java.lang.String property, java.util.List<V> defaultValue, java.util.function.Function<java.lang.String,V> decoder, java.util.function.Function<V,java.lang.String> encoder) Instantiates a Value representing the given property.
PropertyValue<java.lang.Boolean>	propertyValue(java.lang.String property, java.lang.Boolean defaultValue) Instantiates a Value representing the given property.
PropertyValue<java.lang.Double>	propertyValue(java.lang.String property, java.lang.Double defaultValue) Instantiates a Value representing the given property.
PropertyValue<java.lang.Integer>	propertyValue(java.lang.String property, java.lang.Integer defaultValue) Instantiates a Value representing the given property.
PropertyValue<java.lang.String>	propertyValue(java.lang.String property, java.lang.String defaultValue) Instantiates a Value representing the given property.
<V> PropertyValue<V>	propertyValue(java.lang.String property, V defaultValue, java.util.function.Function<java.lang.String,V> decoder, java.util.function.Function<V,java.lang.String> encoder) Instantiates a Value representing the given property.
static java.util.Properties	readFromFile(java.io.File propertiesFile) Reads all properties from the given properties file if it exists
void	removeAll(java.lang.String prefix) Removes all properties with the given prefix
void	setProperty(java.lang.String property, java.lang.String value) Sets the value of the given property
void	writeToFile(java.io.File propertiesFile) Writes the stored properties to a file

Methods inherited from class java.lang.Object

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

Field Detail

VALUE_SEPARATOR

public static final java.lang.String VALUE_SEPARATOR

The separator used to separate multiple values.

See Also:

Constant Field Values

Constructor Detail

PropertyStore

public PropertyStore(java.io.File propertiesFile)
              throws java.io.IOException

Instantiates a new PropertyStore backed by the given file. If the file exists this PropertyStore is initialized with the properties and values found in it.

Parameters:

propertiesFile - the file to read from initially

Throws:

java.io.IOException - in case the given properties file exists but reading it failed

PropertyStore

public PropertyStore(java.util.Properties properties)

Instantiates a new PropertyStore initialized with the given properties.

Parameters:

properties - the initial properties

Method Detail

propertyValue

public PropertyValue<java.lang.Boolean> propertyValue(java.lang.String property,
                                                      java.lang.Boolean defaultValue)

Instantiates a Value representing the given property.

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no value is present and when the value is set to null

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

propertyValue

public PropertyValue<java.lang.String> propertyValue(java.lang.String property,
                                                     java.lang.String defaultValue)

Instantiates a Value representing the given property.

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no value is present and when the value is set to null

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

propertyValue

public PropertyValue<java.lang.Integer> propertyValue(java.lang.String property,
                                                      java.lang.Integer defaultValue)

Instantiates a Value representing the given property.

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no value is present and when the value is set to null

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

propertyValue

public PropertyValue<java.lang.Double> propertyValue(java.lang.String property,
                                                     java.lang.Double defaultValue)

Instantiates a Value representing the given property.

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no value is present and when the value is set to null

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

propertyValue

public <V> PropertyValue<V> propertyValue(java.lang.String property,
                                          V defaultValue,
                                          java.util.function.Function<java.lang.String,V> decoder,
                                          java.util.function.Function<V,java.lang.String> encoder)

Instantiates a Value representing the given property.

Type Parameters:

V - the value type

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no initial value is present

decoder - a decoder for decoding the value from a string

encoder - an encoder for encoding the value to a string

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property, decoder or encoder is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

propertyListValue

public <V> PropertyValue<java.util.List<V>> propertyListValue(java.lang.String property,
                                                              java.util.List<V> defaultValue,
                                                              java.util.function.Function<java.lang.String,V> decoder,
                                                              java.util.function.Function<V,java.lang.String> encoder)

Instantiates a Value representing the given property.

Type Parameters:

V - the value type

Parameters:

property - the configuration property identifying this value

defaultValue - the default value to use if no initial value is present

decoder - a decoder for decoding the value from a string

encoder - an encoder for encoding the value to a string

Returns:

the configuration value

Throws:

java.lang.NullPointerException - if property, decoder or encoder is null

java.lang.IllegalArgumentException - in case a Value for the given property has already been created

getPropertyValue

public <V> PropertyValue<V> getPropertyValue(java.lang.String property)

Returns the Value associated with the given property, null if none has been created.

Type Parameters:

V - the value type

Parameters:

property - the property

Returns:

the configuration value or null if none is found

setProperty

public void setProperty(java.lang.String property,
                        java.lang.String value)

Sets the value of the given property

Parameters:

property - the property

value - the value

Throws:

java.lang.IllegalArgumentException - in the property is value bound

getProperty

public java.lang.String getProperty(java.lang.String property)

Retrieves the value for the given property, null if no value is present

Parameters:

property - the property

Returns:

the value or null if no value is present

getProperties

public java.util.List<java.lang.String> getProperties(java.lang.String prefix)

Returns the values associated with the properties with the given prefix

Parameters:

prefix - the property prefix

Returns:

all values associated with the properties with the given prefix

getPropertyNames

public java.util.List<java.lang.String> getPropertyNames(java.lang.String prefix)

Returns all property names with the given prefix

Parameters:

prefix - the property name prefix

Returns:

all property names with the given prefix

containsProperty

public boolean containsProperty(java.lang.String property)

Returns true if this PropertyStore contains a value for the given property

Parameters:

property - the property

Returns:

true if a value for the given property exists

removeAll

public void removeAll(java.lang.String prefix)

Removes all properties with the given prefix

Parameters:

prefix - the prefix

Throws:

java.lang.IllegalArgumentException - in case any of the properties with the given prefix are value bound

writeToFile

public void writeToFile(java.io.File propertiesFile)
                 throws java.io.IOException

Writes the stored properties to a file

Parameters:

propertiesFile - the properties file to write to

Throws:

java.io.IOException - in case writing the file was not successful

readFromFile

public static java.util.Properties readFromFile(java.io.File propertiesFile)
                                         throws java.io.IOException

Reads all properties from the given properties file if it exists

Parameters:

propertiesFile - the properties file to read from

Returns:

the properties read from the given file

Throws:

java.io.IOException - in case the file exists but can not be read