edu.wisc.ssec.mcidasv.jython

Class Interpreter

java.lang.Object

org.python.util.PythonInterpreter

org.python.util.InteractiveInterpreter

edu.wisc.ssec.mcidasv.jython.Interpreter

public class Interpreter
extends org.python.util.InteractiveInterpreter

Field Summary

Fields

Modifier and Type	Field and Description
private ConsoleCallback	callback A hook that allows external classes to respond to events.
private static String	CONSOLE_FILENAME Dummy filename for the interactive interpreter.
private boolean	moreInput Whether or not jython needs more input to run something.
private ByteArrayOutputStream	stderr Stream used for error output.
private ByteArrayOutputStream	stdout Stream used for normal output.
private boolean	thinking Whether or not Jython is working on something

Fields inherited from class org.python.util.InteractiveInterpreter

buffer, filename

Fields inherited from class org.python.util.PythonInterpreter

cflags, systemState, threadLocals

Constructor Summary

Constructors

Constructor and Description
Interpreter(org.python.core.PySystemState state, ByteArrayOutputStream stdout, ByteArrayOutputStream stderr) Creates a Jython interpreter based upon the specified system state and whose output streams are mapped to the specified byte streams.

Method Summary

Methods

Modifier and Type	Method and Description
private static String	clearStream(String command, ByteArrayOutputStream stream) Removes and returns all existing text from stream.
void	handleException(Console console, Throwable e) Sends error information to the specified console.
void	handleStreams(Console console, String command) Sends the contents of stdout and stderr on their merry way.
boolean	isBusy() Determines whether or not Jython is busy.
boolean	needMoreInput()
boolean	push(Console console, String line) Here's the magic!
protected void	setCallbackHandler(ConsoleCallback newCallback) Registers a new callback handler with the interpreter.

Methods inherited from class org.python.util.InteractiveInterpreter

interrupt, resetbuffer, runcode, runsource, runsource, runsource, showexception, write

Methods inherited from class org.python.util.PythonInterpreter

cleanup, compile, compile, compile, compile, eval, eval, exec, exec, execfile, execfile, execfile, get, get, getLocals, getSystemState, initialize, set, set, setErr, setErr, setErr, setIn, setIn, setIn, setLocals, setOut, setOut, setOut, setSystemState, threadLocalStateInterpreter

Methods inherited from class java.lang.Object

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

Field Detail

CONSOLE_FILENAME

private static final String CONSOLE_FILENAME

Dummy filename for the interactive interpreter.

See Also:

Constant Field Values

stderr

private ByteArrayOutputStream stderr

Stream used for error output.

stdout

private ByteArrayOutputStream stdout

Stream used for normal output.

moreInput

private boolean moreInput

Whether or not jython needs more input to run something.

callback

private ConsoleCallback callback

A hook that allows external classes to respond to events.

thinking

private boolean thinking

Whether or not Jython is working on something

Constructor Detail

Interpreter

public Interpreter(org.python.core.PySystemState state,
           ByteArrayOutputStream stdout,
           ByteArrayOutputStream stderr)

Creates a Jython interpreter based upon the specified system state and whose output streams are mapped to the specified byte streams.

Additionally, the "__main__" module is imported by default so that the locals namespace makes sense.

Parameters:

state - The system state you want to use with the interpreter.

stdout - The stream Jython will use for standard output.

stderr - The stream Jython will use for error output.

Method Detail

setCallbackHandler

protected void setCallbackHandler(ConsoleCallback newCallback)

Registers a new callback handler with the interpreter. This mechanism allows external code to easily react to events taking place in the interpreter.

Parameters:

newCallback - The new callback handler.

push

public boolean push(Console console,
           String line)

Here's the magic! Basically just accumulates a buffer that gets passed off to jython-land until it can run.

Parameters:

line - A Jython command.

Returns:

False if Jython did something. True if more input is needed.

isBusy

public boolean isBusy()

Determines whether or not Jython is busy.

Returns:

true if busy, false otherwise.

needMoreInput

public boolean needMoreInput()

Returns:

Whether or not Jython needs more input to run something.

handleStreams

public void handleStreams(Console console,
                 String command)

Sends the contents of stdout and stderr on their merry way. Both streams are emptied as a result.

Parameters:

console - Console where the command originated.

command - The command that was executed. Null values are permitted, as they signify that no command was entered for any generated output.

clearStream

private static String clearStream(String command,
                 ByteArrayOutputStream stream)

Removes and returns all existing text from stream.

Parameters:

command - Command that was executed. Null values are permitted and imply that no command is "associated" with text in stream.

stream - Stream to be cleared out.

Returns:

The contents of stream before it was reset.

See Also:

handleStreams(Console, String)

handleException

public void handleException(Console console,
                   Throwable e)

Sends error information to the specified console.

Parameters:

console - The console that caused the exception.

e - The exception!