Interface PropertyProvider

All Known Implementing Classes:

PropertyProviderDefault

public interface PropertyProvider

A property provider is used to access an application's arguments at runtime. It synchronizes command line arguments with Java runtime properties and provides a unified way to access, configure and parse properties. The following example code shows how to use a property provider to handle command line arguments:

 private static final Property[] localProps = {
       new PropertyCfg<String>("de.mid.myArg", "this is the description for de.mid.myArg"),
       new PropertyCfg<Boolean>("de.mid.myFlag", false, "this is the description for de.mid.myFlag")
       }

 static public main(String[] argv) {
       PropertyProvider propProv = new PropertyProviderDefault();
       List<Property> tmp = Arrays.asList(localProps);
       propProv.providePropertyList(tmp);
       // further initialization
        ...

       // provide and parse command line arguments
       propProv.InitWithCommandLineArguments(argv);
 }

Author:

borschet

See Also:

• Property
• PropertyCfg
• PropertyProviderDefault

Method Summary

Modifier and Type	Method	Description
void	disableValidateConfig()	Disables stringent validation of the configuration.
void	enableValidateConfig()	Enables stringent validation of the configuration.
List<Property>	getAllValidProperties()
boolean	getBooleanProperty(String key)	A property getter for Boolean properties.
Class<?>[]	getClassListProperty(String key)	Gets a list of classes from a given string property.
Class<?>	getClassProperty(String key)	A property getter for class properties.
<T extends Enum<T>> T	getEnumProperty(Class<T> cls, String key)	A property getter for enumeration type.
File[]	getFileListProperty(String key)	Gets a list of files given with a string property value.
File	getFileProperty(String key)	A property getter for File properties.
int	getIntegerProperty(String key)	A property getter for integer properties.
boolean	getOptionalBooleanProperty(String key)	Tries to invoke getBooleanProperty(String) and returns the given value, otherwise the configured default value is returned.
Class<?>[]	getOptionalClassListProperty(String key, Class<?>[] defaultValue)	Invokes getClassListProperty()
Class<?>	getOptionalClassProperty(String key)	Tries to invoke getClassProperty(String)
<T extends Enum<T>> T	getOptionalEnumProperty(Class<T> cls, String key)	Tries to invoke getEnumProperty(Class, String)
File[]	getOptionalFileListProperty(String key, File[] defaultValue)	Invokes getFileListProperty()
File	getOptionalFileProperty(String key)	Tries to invoke getFileProperty(String)
int	getOptionalIntegerProperty(String key)	Invokes getIntegerProperty()
String	getOptionalStringProperty(String key)	Invokes getStringProperty()
String	getStringProperty(String key)	A property getter for string properties.
void	InitWithCommandLineArguments(String[] args)	Initializes the property provider with an array of command line argument strings, checks the given values against the configuration and prepares the values for use with the typed getter methods.
boolean	isPropertySet(String key)	Returns true if the property with the given key is existing and set, else returns false.
void	provideProperty(Property prop)	Adds precisely one property that can be used at runtime.
void	providePropertyList(List<Property> props)	Configures a list of valid properties to be used at runtime.
void	setProperty(String key, String value)	Set the value for an existing property.

Method Details

InitWithCommandLineArguments

void InitWithCommandLineArguments(String[] args)
                           throws UnknownArgumentException

Initializes the property provider with an array of command line argument strings, checks the given values against the configuration and prepares the values for use with the typed getter methods. This means that the command line arguments are parsed according to the format "<key>=<value>". The property provider checks every given string argument so that they correspond with a valid configured property. If no such property can be found, an exception is raised. This behavior can be prevented by calling disableValidateConfig() before the property provider is initialized.

Throws:

UnknownArgumentException - if the list of command line arguments contains a property that was not previously configured and this check is not disabled.

provideProperty

void provideProperty(Property prop)

Adds precisely one property that can be used at runtime.

providePropertyList

void providePropertyList(List<Property> props)

Configures a list of valid properties to be used at runtime.

getAllValidProperties

List<Property> getAllValidProperties()

Returns:

all previously configured properties.

enableValidateConfig

void enableValidateConfig()

Enables stringent validation of the configuration.

See Also:

• InitWithCommandLineArguments(String[])

disableValidateConfig

void disableValidateConfig()

Disables stringent validation of the configuration.

See Also:

• InitWithCommandLineArguments(String[])

getBooleanProperty

boolean getBooleanProperty(String key)
                    throws MissingArgumentException,
InvalidArgumentException

A property getter for Boolean properties.

Throws:

MissingArgumentException - if no such property could be found.

InvalidArgumentException

getClassProperty

Class<?> getClassProperty(String key)
                   throws MissingArgumentException,
InvalidArgumentException

A property getter for class properties.

Throws:

InvalidArgumentException - if the property value cannot be converted into a valid class.

MissingArgumentException - if no such property can be found.

getFileProperty

File getFileProperty(String key)
              throws MissingArgumentException,
InvalidArgumentException

A property getter for File properties.

Returns:

A file object created with File(java.lang.String).

Throws:

MissingArgumentException - if no such property could be found.

InvalidArgumentException

getIntegerProperty

int getIntegerProperty(String key)
                throws MissingArgumentException,
InvalidArgumentException

A property getter for integer properties.

Throws:

InvalidArgumentException - if the property value cannot be converted into an integer.

MissingArgumentException - if no such property can be found.

getStringProperty

String getStringProperty(String key)
                  throws MissingArgumentException

A property getter for string properties.

Throws:

MissingArgumentException - if no such property can be found.

getEnumProperty

<T extends Enum<T>> T getEnumProperty(Class<T> cls,
 String key)
                               throws MissingArgumentException,
InvalidArgumentException

A property getter for enumeration type.

Parameters:

cls - the property's enumeration type

key - the key value

Returns:

an instance of the enumeration

Throws:

InvalidArgumentException

MissingArgumentException - if no such property can be found.

getOptionalBooleanProperty

boolean getOptionalBooleanProperty(String key)
                            throws InvalidArgumentException

Tries to invoke getBooleanProperty(String) and returns the given value, otherwise the configured default value is returned.

Parameters:

key - the argument key value

Returns:

true, if the property's string value is "true", otherwise false

Throws:

InvalidArgumentException

getOptionalClassProperty

Class<?> getOptionalClassProperty(String key)
                           throws InvalidArgumentException

Tries to invoke getClassProperty(String)

Parameters:

key - the argument key value

Returns:

the given value, otherwise the configured default value

Throws:

InvalidArgumentException - in case the given string cannot be converted into a valid class.

getOptionalFileProperty

File getOptionalFileProperty(String key)
                      throws InvalidArgumentException

Tries to invoke getFileProperty(String)

Returns:

the given value, otherwise the configured default value

Throws:

InvalidArgumentException

getOptionalIntegerProperty

int getOptionalIntegerProperty(String key)
                        throws InvalidArgumentException

Invokes getIntegerProperty()

Returns:

its result if defined, otherwise the configured default value

Throws:

InvalidArgumentException - If the property's string value cannot be converted into an integer.

getOptionalStringProperty

String getOptionalStringProperty(String key)

Invokes getStringProperty()

Returns:

its result if defined, otherwise the configured default value

getOptionalEnumProperty

<T extends Enum<T>> T getOptionalEnumProperty(Class<T> cls,
 String key)
                                       throws InvalidArgumentException

Tries to invoke getEnumProperty(Class, String)

Parameters:

cls - the property's enumeration type

key - the key value

Returns:

the given value, otherwise the configured default value

Throws:

InvalidArgumentException - if the conversion from the value to a valid member of the given enumeration fails.

getClassListProperty

Class<?>[] getClassListProperty(String key)
                         throws MissingArgumentException,
InvalidArgumentException

Gets a list of classes from a given string property. Each class specifications must be separated by a File.pathSeparator.

Returns:

an array of classes.

Throws:

InvalidArgumentException - if an entry of the string list cannot be converted into a valid class.

MissingArgumentException - if no such property can be found.

getFileListProperty

File[] getFileListProperty(String key)
                    throws MissingArgumentException,
InvalidArgumentException

Gets a list of files given with a string property value. The single file specifications must be separated by File.pathSeparator.

Returns:

an array of file instances.

Throws:

MissingArgumentException - if no such property can be found.

InvalidArgumentException

getOptionalClassListProperty

Class<?>[] getOptionalClassListProperty(String key,
 Class<?>[] defaultValue)
                                 throws InvalidArgumentException

Invokes getClassListProperty()

Returns:

its result if defined, otherwise the configured default value

Throws:

InvalidArgumentException - if the property string value cannot be converted into a list of classes.

getOptionalFileListProperty

File[] getOptionalFileListProperty(String key,
 File[] defaultValue)

Invokes getFileListProperty()

Returns:

its result if defined, otherwise the configured default value

isPropertySet

boolean isPropertySet(String key)

Returns true if the property with the given key is existing and set, else returns false.

Parameters:

key - key of the property

Returns:

true if property with key is set.

setProperty

void setProperty(String key,
 String value)

Set the value for an existing property. If the property does not exist, nothing is done.

Parameters:

key -

value -