Jython简单介绍

前言

Jython(原 JPython)，是一个用 Java 语言写的 Python 解释器。由于python语法简洁，写起来快，而且目前有很多现成的算法库，所以别的语言也想坐享其成，Java也不例外，如果能直接调用这些库，那对Java的普及将更为有力。

• 需要注意的是目前Jython只支持python2.x，以下给出一个case案例。

python

Test.py

def wdd(a, b):
    return a + b

java

依赖

<dependency>
    <groupId>org.python</groupId>
    <artifactId>jython-standalone</artifactId>
    <version>2.7.0</version>
</dependency>

JpythonUtil.java

import org.python.core.Py;
import org.python.core.PyFunction;
import org.python.core.PyObject;
import org.python.util.PythonInterpreter;

public class JpythonUtil {

    public static String runPythonMethod(PythonInterpreter interpreter, String handlerFunc, String fieldVal) {
        PyFunction func = (PyFunction)interpreter.get(handlerFunc, PyFunction.class);
        PyObject pyObject = func.__call__(Py.java2py(fieldVal));
        if (pyObject==null) {
            return null;
        } else if (pyObject.toString().equals("null")) {
            return null;
        } else if (pyObject.toString().equals("None")) {
            return null;
        }else {
            return pyObject.toString();
        }
    }

    public static String runPythonMethod(PythonInterpreter interpreter, String handlerFunc, Integer param1, Integer param2) {
        PyFunction func = (PyFunction)interpreter.get(handlerFunc, PyFunction.class);
        PyObject pyObject = func.__call__(Py.java2py(param1), Py.java2py(param2));
        if (pyObject==null) {
            return null;
        } else if (pyObject.toString().equals("null")) {
            return null;
        } else if (pyObject.toString().equals("None")) {
            return null;
        }else {
            return pyObject.toString();
        }
    }
    
    public static PythonInterpreter initPythonEnv(String pyProjectDir, String pyDependDir, String pyFile) {
        PythonInterpreter interpreter = new PythonInterpreter();
        interpreter.exec("import sys");
        interpreter.exec("sys.path.append(\"" + pyProjectDir + "\")");
        interpreter.exec("sys.path.append(\"" + pyDependDir + "\")");
        interpreter.execfile(pyFile);
        return interpreter;
    }

    public static void closePythonEnv(PythonInterpreter interpreter) {
        interpreter.cleanup();
        interpreter.close();
    }

    public static void main(String[] args) {
        String pyProjectDir = "/Users/dengpengfei/PycharmProjects/PySpark";
        String pyDependDir = "/Users/dengpengfei/PycharmProjects/Venv2.7/lib/python2.7/site-packages";
        String pyFile = "/Users/dengpengfei/PycharmProjects/PySpark/Test.py";
        PythonInterpreter interpreter = initPythonEnv(pyProjectDir, pyDependDir, pyFile);

        String line = runPythonMethod(interpreter, "wdd", 1, 1);
        System.out.println(line);
    }
}

结

目前这种java调用python的可行性是没问题的，但是随着python3.x的广泛使用，Jython的迭代还需加快呀。