public class

OptionConverter

extends Object
java.lang.Object
   ↳ org.apache.log4j.helpers.OptionConverter

Class Overview

A convenience class to convert property values to specific types.

Summary

Public Methods
static String[] concatanateArrays(String[] l, String[] r)
static String convertSpecialChars(String s)
static String findAndSubst(String key, Properties props)
Find the value corresponding to key in props.
static String getSystemProperty(String key, String def)
Very similar to System.getProperty except that the SecurityException is hidden.
static Object instantiateByClassName(String className, Class superClass, Object defaultValue)
Instantiate an object given a class name.
static Object instantiateByKey(Properties props, String key, Class superClass, Object defaultValue)
static void selectAndConfigure(URL url, String clazz, LoggerRepository hierarchy)
Configure log4j given a URL.
static String substVars(String val, Properties props)
Perform variable substitution in string val from the values of keys found in the system propeties.
static boolean toBoolean(String value, boolean dEfault)
If value is "true", then true is returned.
static long toFileSize(String value, long dEfault)
static int toInt(String value, int dEfault)
static Level toLevel(String value, Level defaultValue)
Converts a standard or custom priority level to a Level object.
[Expand]
Inherited Methods
From class java.lang.Object

Public Methods

public static String[] concatanateArrays (String[] l, String[] r)

public static String convertSpecialChars (String s)

public static String findAndSubst (String key, Properties props)

Find the value corresponding to key in props. Then perform variable substitution on the found value.

public static String getSystemProperty (String key, String def)

Very similar to System.getProperty except that the SecurityException is hidden.

Parameters
key The key to search for.
def The default value to return.
Returns
  • the string value of the system property, or the default value if there is no property with that key.

public static Object instantiateByClassName (String className, Class superClass, Object defaultValue)

Instantiate an object given a class name. Check that the className is a subclass of superClass. If that test fails or the object could not be instantiated, then defaultValue is returned.

Parameters
className The fully qualified class name of the object to instantiate.
superClass The class to which the new object should belong.
defaultValue The object to return in case of non-fulfillment

public static Object instantiateByKey (Properties props, String key, Class superClass, Object defaultValue)

public static void selectAndConfigure (URL url, String clazz, LoggerRepository hierarchy)

Configure log4j given a URL.

The url must point to a file or resource which will be interpreted by a new instance of a log4j configurator.

All configurations steps are taken on the hierarchy passed as a parameter.

Parameters
url The location of the configuration file or resource.
clazz The classname, of the log4j configurator which will parse the file or resource at url. This must be a subclass of Configurator, or null. If this value is null then a default configurator of PropertyConfigurator is used, unless the filename pointed to by url ends in '.xml', in which case DOMConfigurator is used.
hierarchy The Hierarchy to act on.

public static String substVars (String val, Properties props)

Perform variable substitution in string val from the values of keys found in the system propeties.

The variable substitution delimeters are ${ and }.

For example, if the System properties contains "key=value", then the call

     String s = OptionConverter.substituteVars("Value of key is ${key}.");
     
will set the variable s to "Value of key is value.".

If no value could be found for the specified key, then the props parameter is searched, if the value could not be found there, then substitution defaults to the empty string.

For example, if system propeties contains no value for the key "inexistentKey", then the call

     String s = OptionConverter.subsVars("Value of inexistentKey is [${inexistentKey}]");
     
will set s to "Value of inexistentKey is []"

An java.lang.IllegalArgumentException is thrown if val contains a start delimeter "${" which is not balanced by a stop delimeter "}".

Author Avy Sharell

Parameters
val The string on which variable substitution is performed.
Throws
IllegalArgumentException if val is malformed.

public static boolean toBoolean (String value, boolean dEfault)

If value is "true", then true is returned. If value is "false", then true is returned. Otherwise, default is returned.

Case of value is unimportant.

public static long toFileSize (String value, long dEfault)

public static int toInt (String value, int dEfault)

public static Level toLevel (String value, Level defaultValue)

Converts a standard or custom priority level to a Level object.

If value is of form "level#classname", then the specified class' toLevel method is called to process the specified level string; if no '#' character is present, then the default Level class is used to process the level value.

As a special case, if the value parameter is equal to the string "NULL", then the value null will be returned.

If any error occurs while converting the value to a level, the defaultValue parameter, which may be null, is returned.

Case of value is insignificant for the level level, but is significant for the class name part, if present.