org.melati.util
Class PropertiesUtils

java.lang.Object
  org.melati.util.PropertiesUtils

public final class PropertiesUtils
extends Object

Useful things to do with properties files.

Method Summary

static Properties	fromFile(File path) Get a Properties object from a file.
static Properties	fromResource(Class<?> clazz, String name) Get a Properties object from a Class.
static int	getOrDefault_int(Properties properties, String propertyName, int def) Get an Integer property from a Properties object or make a fuss.
static String	getOrDefault(Properties properties, String propertyName, String def) Get a property or return the supplied default.
static int	getOrDie_int(Properties properties, String propertyName) Get an Integer property.
static String	getOrDie(Properties properties, String propertyName) Return a property.
static Object	instanceOfNamedClass(Properties properties, String propertyName, String interfaceClassName, String defaultName) Instantiate a Class.
static Object	instanceOfNamedClass(String className, String interfaceClassName) Instantiate an interface.

Methods inherited from class java.lang.Object

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

Method Detail

fromFile

public static Properties fromFile(File path)
                           throws IOException

Get a Properties object from a file.

Parameters:

path - a File path name

Returns:

a Properties object

Throws:

IOException - if there is a problem loading the file

fromResource

public static Properties fromResource(Class<?> clazz,
                                      String name)
                               throws IOException

Get a Properties object from a Class.

Parameters:

clazz - the Class to look up

name - the property file name

Returns:

a Properties object

Throws:

IOException - if the file cannot load or is not found

getOrDie

public static String getOrDie(Properties properties,
                              String propertyName)
                       throws NoSuchPropertyException

Return a property.

Parameters:

properties - the Properties object to look in

propertyName - the property to get

Returns:

the property value

Throws:

NoSuchPropertyException - if the property is not set

getOrDefault

public static String getOrDefault(Properties properties,
                                  String propertyName,
                                  String def)

Get a property or return the supplied default.

Parameters:

properties - the Properties object to look in

propertyName - the property to get

def - the default to return if not found

Returns:

the property value

getOrDie_int

public static int getOrDie_int(Properties properties,
                               String propertyName)
                        throws NoSuchPropertyException,
                               FormatPropertyException

Get an Integer property.

Parameters:

properties - the Properties object to look in

propertyName - the property to get

Returns:

the int property value

Throws:

NoSuchPropertyException - if it is not found

FormatPropertyException - if it is not an Integer

getOrDefault_int

public static int getOrDefault_int(Properties properties,
                                   String propertyName,
                                   int def)
                            throws FormatPropertyException

Get an Integer property from a Properties object or make a fuss.

Parameters:

properties - a Properties

propertyName - the name of the property

def - cater for multiple definitions, with increment numbers

Returns:

the property as an int

Throws:

FormatPropertyException - if it is not an Integer

instanceOfNamedClass

public static Object instanceOfNamedClass(String className,
                                          String interfaceClassName)
                                   throws InstantiationPropertyException

Instantiate an interface.

Parameters:

className - the name of the class

interfaceClassName - the interface Class name

Returns:

a new object

Throws:

InstantiationPropertyException - if the named class does not descend from the interface

instanceOfNamedClass

public static Object instanceOfNamedClass(Properties properties,
                                          String propertyName,
                                          String interfaceClassName,
                                          String defaultName)
                                   throws InstantiationPropertyException

Instantiate a Class.

Parameters:

properties - a Properties

propertyName - the name of the property

interfaceClassName - the interface name

defaultName - a default concrete class if the property is undefined

Returns:

a new Object

Throws:

InstantiationPropertyException - if there is a problem