org.python.util

Class jython

java.lang.Object

org.python.util.jython

public class jython
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	CONSOLE_LOG_FORMAT The default format for console log messages in the command-line Jython.

Constructor Summary

Constructors

Constructor and Description
jython()

Method Summary

Modifier and Type	Method and Description
static void	loggingToConsole() Events from within the Jython implementation are surfaced through the java.util.logging.Logger org.python or a child of it.
static void	loggingToDefault() Mostly reverse the effects of loggingToConsole(), by removing from the "org.python" logger the handler that prints to the console, and setting the "org.python" logger to propagate records to its parent handlers.
static void	main(java.lang.String[] args) Main Jython program, following the structure and logic of CPython main.c to produce the same behaviour.
static void	run(java.lang.String[] args) Deprecated.
static int	runJar(java.lang.String filename) Runs a JAR file, by executing the code found in the file __run__.py, which should be in the root of the JAR archive.

Methods inherited from class java.lang.Object

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

Field Detail

CONSOLE_LOG_FORMAT

public static final java.lang.String CONSOLE_LOG_FORMAT

The default format for console log messages in the command-line Jython. See java.util.logging.SimpleFormatter for an explanation of the syntax.

This format is used in the absence of other logging preferences, and only if property python.logging.default is not defined. Jython tests for definitions in the system properties of java.util.logging.config.class, java.util.logging.config.file, and java.util.logging.SimpleFormatter.format and if none of these is defined, it sets the last of them to this value.

You can choose something else, for example to log with millisecond time stamps, launch Jython as:

 jython -vv -J-Djava.util.logging.SimpleFormatter.format="[%1$tT.%1$tL] %3$s: (%4$s) %5$s%n"
 

Depending on your shell, the argument may need quoting or escaping.

See Also:

Constant Field Values

Constructor Detail

jython

public jython()

Method Detail

loggingToConsole

public static void loggingToConsole()

Events from within the Jython implementation are surfaced through the java.util.logging.Logger org.python or a child of it. When Jython is used interactively, we normally want these to emerge on the console, in a succinct form, not via the java.util.logging root logger. This method is called by main(String[]) to achieve that.

The root logger format is hard to read for humans. The logging level of the handler defaults to INFO, and does not respond to the -v option. (It could be made to, but then all logging would be be turned up together.) This method makes these adjustments to logging:

• The format SimpleFormatter is replaced with a simpler format (but only if no other logging customisation is present). (Affects all logging.)
• A console handler is installed for logger org.python using that a SimpleFormatter and accepts all levels.
• Logger org.python is told not to propagate records to parent handlers (so that messages are not emitted twice.

The level of logger org.python and its child loggers by default, which determines admission of logging, reflects the "verbosity" set by the `-v` option.

loggingToDefault

public static void loggingToDefault()

Mostly reverse the effects of loggingToConsole(), by removing from the "org.python" logger the handler that prints to the console, and setting the "org.python" logger to propagate records to its parent handlers. The method does not try to reset the property java.util.logging.SimpleFormatter.format, which is in any case only read during static initialisation by SimpleFormatter.

runJar

public static int runJar(java.lang.String filename)

Runs a JAR file, by executing the code found in the file __run__.py, which should be in the root of the JAR archive. Note that __name__ is set to the base name of the JAR file and not to "__main__" (for historical reasons). This method does not handle exceptions. the caller should handle any (Py)Exceptions thrown by the code.

Parameters:

filename - The path to the filename to run.

Returns:

0 on normal termination (otherwise throws PyException).

run

@Deprecated
public static void run(java.lang.String[] args)

Deprecated.

Now equivalent to main(String[]), which is to be preferred.

main

public static void main(java.lang.String[] args)

Main Jython program, following the structure and logic of CPython main.c to produce the same behaviour. The argument to the method is the argument list supplied after the class name in the java command. Arguments up to the executable script name are options for Jython; arguments after the executable script are supplied in sys.argv. "Executable script" here means a Python source file name, a module name (following the -m option), a literal command (following the -c option), or a JAR file name (following the -jar option). As a special case of the file name, "-" is allowed, meaning take the script from standard input.

The main difference for the caller stems from a difference between C and Java: in C, the argument list (argv) begins with the program name, while in Java all elements of (args) are arguments to the program.

Parameters:

args - arguments to the program.