PemJa
PemJa is an open source cross language call framework based on FFI. It aims to provide a high-performance
framework of calling between different languages.
Python binary installers for the latest released version are available at the Python package index
pip install pemja
Java Maven Dependency
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>pemja</artifactId>
<version>{version}</version>
</dependency>
Prerequisites for building PemJa:
git clone https://github.com/alibaba/pemja.git
cd pemja
mvn clean install -DskipTests
pip install -r dev/dev-requirements.txt
python setup.py sdist
pip install dist/*.tar.gz
String path = ...;
PythonInterpreterConfig config = PythonInterpreterConfig
.newBuilder()
.setPythonExec("python3") // specify python exec
.addPythonPaths(path) // add path to search path
.build();
PythonInterpreter interpreter = new PythonInterpreter(config);
// set & get
interpreter.set("a", 12345);
interpreter.get("a"); // Object
interpreter.get("a", Integer.class); // Integer
// exec & eval
interpreter.exec("print(a)");
// invoke functions
interpreter.exec("import str_upper");
String result = interpreter.invoke("str_upper.upper", "abcd");
// Object invoke(String name, Object... args);
// Object invoke(String name, Object[] args, Map<String, Object> kwargs);
// invoke object methods
/*
// invoke.py
class A:
def __init__(self):
self._a = 0
def get_value(self):
return self._a
def add(self, n):
self._a += n
def add_all(self, *args):
for item in args:
self._a += item
return self._a
def minus(self, n):
self._a -= n
return self._a
*/
interpreter.exec("import invoke");
interpreter.exec("a = invoke.A()");
interpreter.invokeMethod("a", "add", 3);
interpreter.invokeMethod("a", "minus", 2);
interpreter.invokeMethod("a", "add_all", 1, 2, 3);
// python callback java methods
/*
// invoke_callback.py
from pemja import findClass
StringBuilder = findClass('java.lang.StringBuilder')
Integer = findClass('java.lang.Integer')
def callback_java():
sb = StringBuilder()
sb.append('pemja')
sb.append('java')
sb.append('python')
sb.append(Integer.toHexString(Integer.MAX_VALUE))
return sb.toString()
*/
interpreter.exec("import call_back")
print(interpreter.invoke("call_back.callback_java"))