org.apache.log4j.helpers

Class OptionConverter

java.lang.Object

org.apache.log4j.helpers.OptionConverter

public class OptionConverter
extends Object

A convenience class to convert property values to specific types.

Method Summary

Modifier and Type	Method and Description
static String[]	concatanateArrays(String[] l, String[] r)
static org.apache.logging.log4j.Level	convertLevel(Level level)
static Level	convertLevel(org.apache.logging.log4j.Level level)
static org.apache.logging.log4j.Level	convertLevel(String level, org.apache.logging.log4j.Level defaultLevel)
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 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 Level	toLevel(String value, Level defaultValue) Converts a standard or custom priority level to a Level object.

Methods inherited from class java.lang.Object

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

Method Detail

concatanateArrays

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

convertSpecialChars

public static String convertSpecialChars(String s)

getSystemProperty

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.

Since:

1.1

toBoolean

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.

Parameters:

value - The value to convert.

dEfault - The default value.

Returns:

the value of the result.

toLevel

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.

Parameters:

value - The value to convert.

defaultValue - The default value.

Returns:

the value of the result.

Since:

1.1

instantiateByClassName

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

Returns:

The created object.

substVars

public static String substVars(String val,
                               Properties props)
                        throws IllegalArgumentException

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 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.

props - The properties to use for the substitution.

Returns:

The substituted string.

Throws:

IllegalArgumentException - if val is malformed.

convertLevel

public static org.apache.logging.log4j.Level convertLevel(String level,
                                                          org.apache.logging.log4j.Level defaultLevel)

convertLevel

public static org.apache.logging.log4j.Level convertLevel(Level level)

convertLevel

public static Level convertLevel(org.apache.logging.log4j.Level level)

findAndSubst

public static String findAndSubst(String key,
                                  Properties props)

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

Parameters:

key - The key used to locate the substitution string.

props - The properties to use in the substitution.

Returns:

The substituted string.