Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.programming;

import java.lang.reflect.Method;

import java.util.List;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.ExpressionEvaluatorLocator;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

@SuppressWarnings("UseSpecificCatch")

public class CallStaticMethodFunction extends AbstractFunction {

    public static final String NAME = "CALL_STATIC";

    public CallStaticMethodFunction() {

        super(

            Function.GROUP_PROGRAMMING, 

            NAME, 

            Range.between(2, Integer.MAX_VALUE),

            "The "+NAME+"() function call a static mehod of a class.",

            NAME+"( className, methodName, arguments... )",

            null,

            "Object",

            false

        );

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        String theClassName = getStr(args,0);

        String theMethodName = getStr(args,1);

        int firstArg = 1;

        if( theClassName == null ) {

            throw new NullPointerException("A class name name was expected to invoke and a null class name was received");

        }

        if( theMethodName == null ) {

            throw new NullPointerException("A method name was expected to invoke and a null methd name was received");

        }

        List<ClassLoader> loaders = ExpressionEvaluatorLocator.getManager().getClassLoaders();

        Class<?> theClass = null;

        for (ClassLoader loader : loaders) {

          try {

            theClass = loader.loadClass(theClassName);

            if( theClass!=null ) {

              break;

            }

          } catch(Throwable th) {

            // Do nothing skip

          }

        }

        if( theClass == null ) {

          throw new ExpressionRuntimeException("Can't localte the class '"+theClassName+"'.");

        }

        Class[] parameterTypes = new Class[args.length-firstArg];

        Object[] parameters = new Object[args.length-firstArg];

        for (int i = 0; i < parameters.length; i++) {

            Object parameter = args[i+firstArg];

            parameters[i] = parameter;

            if( parameter==null ) {

                parameterTypes[i] = null;

            } else {

                parameterTypes[i] = parameter.getClass();

            }

        }

        Method method = theClass.getMethod(theMethodName, parameterTypes);

        Object value = method.invoke(null, parameters);

        return value;

    }

}