ch.obermuhlner.scriptengine.java.execution.MethodExecutionStrategy Maven / Gradle / Ivy

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Java script engine for Java as a scripting language.

There is a newer version: 2.0.0

package ch.obermuhlner.scriptengine.java.execution;

import ch.obermuhlner.scriptengine.java.internal.ReflectionUtil;

import javax.script.ScriptException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.List;

public class MethodExecutionStrategy implements ExecutionStrategy {
    private Method method;
    private Object[] arguments;

    private MethodExecutionStrategy(Method method, Object... arguments) {
        this.method = method;
        this.arguments = arguments;
    }

    @Override
    public Object execute(Object instance) throws ScriptException {
        try {
            return method.invoke(instance, arguments);
        } catch (IllegalAccessException | InvocationTargetException e) {
            throw new ScriptException(e);
        }
    }

    public static MethodExecutionStrategy byMethod(Method method, Object... arguments) {
        return new MethodExecutionStrategy(method, arguments);
    }

    public static MethodExecutionStrategy byArgumentTypes(Class clazz, String methodName, Class[] argumentTypes, Object... arguments) throws ScriptException {
        try {
            Method method = clazz.getMethod(methodName, argumentTypes);
            return byMethod(method, arguments);
        } catch (NoSuchMethodException e) {
            throw new ScriptException(e);
        }
    }

    public static MethodExecutionStrategy byMatchingArguments(Class clazz, String methodName, Object... arguments) throws ScriptException {
        List matchingMethods = new ArrayList<>();
        for (Method method : clazz.getMethods()) {
            if ((method.getModifiers() & Modifier.PUBLIC) != 0) {
                if (ReflectionUtil.matchesArguments(method, arguments)) {
                    matchingMethods.add(method);
                }
            }
        }

        if (matchingMethods.size() == 0) {
            throw new ScriptException("No method '" + methodName + "' with matching arguments found");
        }
        if (matchingMethods.size() > 1) {
            throw new ScriptException("Ambiguous methods '" + methodName + "' with matching arguments found: " + matchingMethods.size());
        }

        return byMethod(matchingMethods.get(0), arguments);
    }

}