org.python.util.PythonInterpreter Maven / Gradle / Ivy
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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
// Copyright (c) Corporation for National Research Initiatives
package org.python.util;
import org.python.core.*;
import java.util.*;
/**
* The PythonInterpreter class is a standard wrapper for a JPython
* interpreter for use embedding in a Java application.
*
* @author Jim Hugunin
* @version 1.0, 02/23/97
*/
public class PythonInterpreter {
PyModule module;
protected PySystemState systemState;
PyObject locals;
protected CompilerFlags cflags = null;
/**
* Initializes the jython runtime. This should only be called once, and
* should be called before any other python objects are created (including a
* PythonInterpreter).
*
* @param preProperties
* A set of properties. Typically System.getProperties() is used.
* @param postProperties
* An other set of properties. Values like python.home,
* python.path and all other values from the registry files can
* be added to this property set. PostProperties will override
* system properties and registry properties.
* @param argv
* Command line argument. These values will assigned to sys.argv.
*/
public static void initialize(Properties preProperties,
Properties postProperties,
String[] argv) {
PySystemState.initialize(preProperties, postProperties, argv);
}
/**
* Create a new Interpreter with an empty dictionary
*/
public PythonInterpreter() {
this(null, null);
}
/**
* Create a new interpreter with the given dictionary to use as its
* namespace
*
* @param dict the dictionary to use
*/
// Optional dictionary willl be used for locals namespace
public PythonInterpreter(PyObject dict) {
this(dict, null);
}
public PythonInterpreter(PyObject dict, PySystemState systemState) {
if (dict == null)
dict = new PyStringMap();
if (systemState == null) {
systemState = Py.getSystemState();
if (systemState == null)
systemState = new PySystemState();
}
module = new PyModule("main", dict);
this.systemState = systemState;
locals = module.__dict__;
setState();
}
protected void setState() {
Py.setSystemState(systemState);
}
/**
* Set the Python object to use for the standard output stream
*
* @param outStream Python file-like object to use as output stream
*/
public void setOut(PyObject outStream) {
systemState.stdout = outStream;
}
/**
* Set a java.io.Writer to use for the standard output stream
*
* @param outStream Writer to use as output stream
*/
public void setOut(java.io.Writer outStream) {
setOut(new PyFile(outStream));
}
/**
* Set a java.io.OutputStream to use for the standard output stream
*
* @param outStream OutputStream to use as output stream
*/
public void setOut(java.io.OutputStream outStream) {
setOut(new PyFile(outStream));
}
public void setErr(PyObject outStream) {
systemState.stderr = outStream;
}
public void setErr(java.io.Writer outStream) {
setErr(new PyFile(outStream));
}
public void setErr(java.io.OutputStream outStream) {
setErr(new PyFile(outStream));
}
/**
* Evaluate a string as Python source and return the result
*
* @param s the string to evaluate
*/
public PyObject eval(String s) {
setState();
return __builtin__.eval(new PyString(s), locals);
}
/**
* Execute a string of Python source in the local namespace
*
* @param s the string to execute
*/
public void exec(String s) {
setState();
Py.exec(Py.compile_flags(s, "", "exec",cflags),
locals, locals);
}
/**
* Execute a Python code object in the local namespace
*
* @param code the code object to execute
*/
public void exec(PyObject code) {
setState();
Py.exec(code, locals, locals);
}
/**
* Execute a file of Python source in the local namespace
*
* @param s the name of the file to execute
*/
public void execfile(String s) {
setState();
__builtin__.execfile_flags(s, locals, locals, cflags);
}
public void execfile(java.io.InputStream s) {
execfile(s, "");
}
public void execfile(java.io.InputStream s, String name) {
setState();
Py.runCode(Py.compile_flags(s, name, "exec",cflags), locals, locals);
}
// Getting and setting the locals dictionary
public PyObject getLocals() {
return locals;
}
public void setLocals(PyObject d) {
locals = d;
}
/**
* Set a variable in the local namespace
*
* @param name the name of the variable
* @param value the value to set the variable to.
Will be automatically converted to an appropriate Python object.
*/
public void set(String name, Object value) {
locals.__setitem__(name.intern(), Py.java2py(value));
}
/**
* Set a variable in the local namespace
*
* @param name the name of the variable
* @param value the value to set the variable to
*/
public void set(String name, PyObject value) {
locals.__setitem__(name.intern(), value);
}
/**
* Get the value of a variable in the local namespace
*
* @param name the name of the variable
*/
public PyObject get(String name) {
return locals.__finditem__(name.intern());
}
/**
* Get the value of a variable in the local namespace Value will be
* returned as an instance of the given Java class.
* interp.get("foo", Object.class) will return the most
* appropriate generic Java object.
*
* @param name the name of the variable
* @param javaclass the class of object to return
*/
public Object get(String name, Class javaclass) {
return Py.tojava(locals.__finditem__(name.intern()), javaclass);
}
public void cleanup() {
systemState.callExitFunc();
}
}