JythonObjectFactory.java

package org.jython;

import org.python.core.Py;
import org.python.core.PyObject;
import org.python.core.PySystemState;

/**
 * Jython Object Factory using PySystemState
 * from: http://www.jython.org/jythonbook/en/1.0/JythonAndJavaIntegration.html#more-efficient-version-of-loosely-coupled-object-factory
 */
@SuppressWarnings("rawtypes")
public class JythonObjectFactory {
  
  
  private final Class interfaceType;
  private final PyObject klass;
  
  // Constructor obtains a reference to the importer, module, and the class name
  public JythonObjectFactory(PySystemState state, Class interfaceType, String moduleName, String className) {
    this.interfaceType = interfaceType;
    PyObject importer = state.getBuiltins().__getitem__(Py.newString("__import__"));
    PyObject module = importer.__call__(Py.newString(moduleName));
    klass = module.__getattr__(className);
    //System.err.println("module=" + module + ",class=" + klass);
  }
  
  // This constructor passes through to the other constructor
  public JythonObjectFactory(Class interfaceType, String moduleName, String className) {
    this(new PySystemState(), interfaceType, moduleName, className);
  }
  
  // All of the followng methods return
  // a coerced Jython object based upon the pieces of information
  // that were passed into the factory. The differences are
  // between them are the number of arguments that can be passed
  // in as arguents to the object.
  
  public Object createObject() {
    return klass.__call__().__tojava__(interfaceType);
  }
  
  
  public Object createObject(Object arg1) {
    return klass.__call__(Py.java2py(arg1)).__tojava__(interfaceType);
  }
  
  public Object createObject(Object arg1, Object arg2) {
    return klass.__call__(Py.java2py(arg1), Py.java2py(arg2)).__tojava__(interfaceType);
  }
  
  public Object createObject(Object arg1, Object arg2, Object arg3)
  {
    return klass.__call__(Py.java2py(arg1), Py.java2py(arg2),
        Py.java2py(arg3)).__tojava__(interfaceType);
  }
  
  public Object createObject(Object args[], String keywords[]) {
    PyObject convertedArgs[] = new PyObject[args.length];
    for (int i = 0; i < args.length; i++) {
      convertedArgs[i] = Py.java2py(args[i]);
    }
    
    return klass.__call__(convertedArgs, keywords).__tojava__(interfaceType);
  }
  
  public Object createObject(Object... args) {
    return createObject(args, Py.NoKeywords);
  }
  
}