WebObjects 5.4.2

com.webobjects.foundation
Class NSProperties

java.lang.Object
  extended by com.webobjects.foundation.NSProperties

public class NSProperties
extends Object

This class extends Java's properties mechanism to merge application properties with the standard system properties available using the java.lang.System.getProperties method. The application properties can come from four sources: the command line, the application's Properties file, the Properties files of any frameworks the application includes, and the file WebObjects.properties in the user's home directory.

This class has only static methods and cannot be instantiated.

Accessing the Properties

To access the application properties you first need to merge the application and command line properties with the system properties. A WebObjects application automatically performs this step for you. You can then access the property as a string, and convert the string to the property's actual data type.

To obtain the application properties and merge them with the system properties you have to invoke setPropertiesFromArgv.

Every property is a key-value pair. For example, on Unix machines, the property value for the key "file.separator" is "/". To access a property corresponding to a particular key, use the java.lang.System.getProperty method. This method returns the property as a string.

If the property string represents a value other than java.lang.String, for example, a boolean value, NSArray, or NSDictionary, you can convert it to the appropriate data type using the NSPropertyListSerialization's booleanForString, arrayForString, or dictionaryForString method, respectively. NSPropertyListSerialization also provides an intForString method to simplify converting a property string to an integer.

The Properties File

The Properties file must be in the format specified by java.io.Properties.

Boolean values, NSArrays, and NSDictionaries must be specified using the property list representation. See the NSPropertyListSerialization class description for more information on property lists.

Command Line Properties

The setPropertiesFromArgv method parses the command line arguments and recognizes the property formats listed in the table below.

Format Example
-Dkey=value   -DWOPort=4321
-key value   -WOAutoOpenInBrowser NO

Properties specified in these formats will be available as system properties after you invoke setPropertiesFromArgv.

See Also:
System.getProperty(java.lang.String), NSProperties.setPropertiesFromArgv(java.lang.String[]), NSPropertyListSerialization

Method Summary
static NSArray arrayForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and convert the property to a string using NSPropertyListSerialization.arrayForString.
static boolean booleanForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and convert it to a boolean using NSPropertyListSerialization.booleanForString.
static NSData dataForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty, convert the property to a property list using NSPropertyListSerialization.propertyListFromString, and convert the property list to an NSData object using NSPropertyListSerialization.dataFromPropertyList.
static NSDictionary dictionaryForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and convert the property to an NSDictionary using NSPropertyListSerialization.dictionaryForString
static double doubleForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and convert the property to a double.
static float floatForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and and convert the property to a float.
static String getProperty(String name)
           
static String getProperty(String name, String defaultValue)
           
static int integerForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and convert it to an integer using NSPropertyListSerialization.intForString.
static long longForKey(String aKey)
          Deprecated. Instead, find the system property using System.getProperty and and convert the property to a long.
static void setPropertiesFromArgv(String[] argv)
          Loads all of the application's properties from all the three sources described in the class description and merges them with the Java System properties.
static String stringForKey(String aKey)
          Deprecated. Use System.getProperty(java.lang.String).
static NSDictionary valuesFromArgv(String[] argv)
          Parses a String array of properties.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getProperty

public static String getProperty(String name)

getProperty

public static String getProperty(String name,
                                 String defaultValue)

arrayForKey

@Deprecated
public static NSArray arrayForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and convert the property to a string using NSPropertyListSerialization.arrayForString.

Parameters:
aKey - input key whose property will be converted to NSArray
Returns:
system property specified by aKey or null if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String), NSPropertyListSerialization.arrayForString(java.lang.String)

booleanForKey

@Deprecated
public static boolean booleanForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and convert it to a boolean using NSPropertyListSerialization.booleanForString.

Parameters:
aKey - input key whose property will be converted to boolean
Returns:
system property specified by aKey or false if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String), NSPropertyListSerialization.booleanForString(java.lang.String)

dataForKey

@Deprecated
public static NSData dataForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty, convert the property to a property list using NSPropertyListSerialization.propertyListFromString, and convert the property list to an NSData object using NSPropertyListSerialization.dataFromPropertyList.

Parameters:
aKey - input key whose property will be converted to NSData
Returns:
system property value or NSData.EmptyData if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String), NSPropertyListSerialization.propertyListFromString(java.lang.String), NSPropertyListSerialization.dataFromPropertyList(java.lang.Object)

dictionaryForKey

@Deprecated
public static NSDictionary dictionaryForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and convert the property to an NSDictionary using NSPropertyListSerialization.dictionaryForString

Parameters:
aKey - input key whose property will be converted to NSDictionary
Returns:
system property value or NSDictionary.EmptyDictionary if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String), NSPropertyListSerialization.dictionaryForString(java.lang.String)

doubleForKey

@Deprecated
public static double doubleForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and convert the property to a double.

Parameters:
aKey - input key whose property will be converted to a double
Returns:
system property value or 0 if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String)

floatForKey

@Deprecated
public static float floatForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and and convert the property to a float.

Parameters:
aKey - input key whose property will be converted to a float
Returns:
system property value or 0 if the system property indicated by aKey does not exist
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String)

integerForKey

@Deprecated
public static int integerForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and convert it to an integer using NSPropertyListSerialization.intForString.

Parameters:
aKey - input key whose property will be converted to an integer
Returns:
system property specified by aKey or 0 if no system property with that name exists
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String), NSPropertyListSerialization.intForString(java.lang.String)

longForKey

@Deprecated
public static long longForKey(String aKey)
Deprecated. Instead, find the system property using System.getProperty and and convert the property to a long.

Parameters:
aKey - input key whose property will be converted to a long
Returns:
system property value or 0 if the property indicated by aKey does not exist
Throws:
NullPointerException - aKey is null
See Also:
System.getProperty(java.lang.String)

setPropertiesFromArgv

public static void setPropertiesFromArgv(String[] argv)
Loads all of the application's properties from all the three sources described in the class description and merges them with the Java System properties.

This method obtains the properties for every bundle in the application including the application and all of the frameworks it includes. It also merges any properties specified by the string array argv into the system properties.

Parameters:
argv - a String array representing extra properties to be merged into system properties
See Also:
Properties

stringForKey

@Deprecated
public static String stringForKey(String aKey)
Deprecated. Use System.getProperty(java.lang.String).

This method will be replaced by finding the system property using System.getProperty(key).

Equivalent to System.getProperty(key).

Parameters:
aKey - system property being inquired
Returns:
value of the property specified by aKey

valuesFromArgv

public static NSDictionary valuesFromArgv(String[] argv)
Parses a String array of properties. Usually, this String array comes from the command line and its format is described in the class description.

Parameters:
argv - a String array of properties to be parsed
Returns:
the parsed properties in an NSDictionary format
See Also:
NSDictionary

Last updated June 2008

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