Main.java

package com.demonwav.stupid;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class Main {

    public static final Object object = new Object() {
        private final Object one = "one";
        private final Object two = "two";
        private final Object three = "three";
        private final Object four = "four";
        private final Object five = "five";
        private final Object six = "six";
        private final Object seven = "seven";
        private final Object eight = "eight";
        private final Object nine = "nine";
        private final Object ten = "ten";

        private void printFields() throws Throwable {
            forMethod(
                getField(Class.forName("java.lang.System"), "out"),
                "println", Class.forName("java.lang.String")
            ).call(
                one + ", " +
                    two + ", " +
                    three + ", " +
                    four + ", " +
                    five + ", " +
                    six + ", " +
                    seven + ", " +
                    eight + ", " +
                    nine + ", " +
                    ten
            );
        }
    };


    public static void main(String[] args) throws Throwable {
        forMethod(
            Class.forName("java.lang.reflect.Array"),
            "set",
            Class.forName("java.lang.Object"),
            int.class,
            Class.forName("java.lang.Object")
        ).call(forMethod(
            Class.forName("java.lang.reflect.Array"),
            "newInstance",
            Class.forName("java.lang.Class"),
            int.class
        ).call(Class.forName("java.lang.Class"), 1), 0, Class.forName("java.io.InputStream"));

        forMethod(
            Class.forName("java.lang.reflect.Array"),
            "set",
            Class.forName("java.lang.Object"),
            int.class,
            Class.forName("java.lang.Object")
        ).call(forMethod(
            Class.forName("java.lang.reflect.Array"),
            "newInstance",
            Class.forName("java.lang.Class"),
            int.class
        ).call(Class.forName("java.lang.Object"), 1), 0, getField(Class.forName("java.lang.System"), "in"));
        forMethod(
            forMethod(
                (Object) Class.forName("java.util.Scanner"),
                "getConstructor",
                (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                               "newInstance",
                                               Class.forName("java.lang.Class"),
                                               int.class
                ).call(Class.forName("java.lang.Class"), 1), "getClass").call()
            ).call(forMethod(
                Class.forName("java.lang.reflect.Array"),
                "newInstance",
                Class.forName("java.lang.Class"),
                int.class
            ).call(Class.forName("java.lang.Class"), 1)),
            "newInstance",
            (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                           "newInstance",
                                           Class.forName("java.lang.Class"),
                                           int.class
            ).call(Class.forName("java.lang.Object"), 1), "getClass").call()
        ).call(forMethod(
            Class.forName("java.lang.reflect.Array"),
            "newInstance",
            Class.forName("java.lang.Class"),
            int.class
        ).call(Class.forName("java.lang.Object"), 1));

        while (true) {
            forMethod(getField(Class.forName("java.lang.System"), "out"), "print", Class.forName("java.lang.String"))
                .call("(S)et field / (G)et field / (C)all method / (Q)uit: ");
            forMethod(getField(Class.forName("java.lang.System"), "out"), "println").call();

            final Object lowerCase = forMethod(forMethod(forMethod(
                forMethod(
                    (Object) Class.forName("java.util.Scanner"),
                    "getConstructor",
                    (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                   "newInstance",
                                                   Class.forName("java.lang.Class"),
                                                   int.class
                    ).call(Class.forName("java.lang.Class"), 1), "getClass").call()
                ).call(forMethod(Class.forName("java.lang.reflect.Array"), "newInstance", Class.forName("java.lang.Class"), int.class).call(
                    Class.forName("java.lang.Class"),
                    1
                )),
                "newInstance",
                (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                               "newInstance",
                                               Class.forName("java.lang.Class"),
                                               int.class
                ).call(Class.forName("java.lang.Object"), 1), "getClass").call()
            ).call(forMethod(Class.forName("java.lang.reflect.Array"), "newInstance", Class.forName("java.lang.Class"), int.class).call(
                Class.forName("java.lang.Object"),
                1
            )), "nextLine").call(), "toLowerCase").call();

            if (lowerCase.equals("q")) {
                forMethod(forMethod(Class.forName("java.lang.Runtime"), "getRuntime").call(), "exit", int.class).call(0);
            } else if (lowerCase.equals("s")) {
                forMethod(getField(Class.forName("java.lang.System"), "out"), "print", Class.forName("java.lang.String"))
                    .call("<fieldName>,<value>: ");
                final Object split = forMethod(forMethod(forMethod(
                    forMethod(
                        (Object) Class.forName("java.util.Scanner"),
                        "getConstructor",
                        (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                       "newInstance",
                                                       Class.forName("java.lang.Class"),
                                                       int.class
                        ).call(Class.forName("java.lang.Class"), 1), "getClass").call()
                    ).call(forMethod(
                        Class.forName("java.lang.reflect.Array"),
                        "newInstance",
                        Class.forName("java.lang.Class"),
                        int.class
                    ).call(
                        Class.forName("java.lang.Class"),
                        1
                    )),
                    "newInstance",
                    (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                   "newInstance",
                                                   Class.forName("java.lang.Class"),
                                                   int.class
                    ).call(Class.forName("java.lang.Object"), 1), "getClass").call()
                ).call(forMethod(Class.forName("java.lang.reflect.Array"), "newInstance", Class.forName("java.lang.Class"), int.class).call(
                    Class.forName("java.lang.Object"),
                    1
                )), "nextLine").call(), "split", Class.forName("java.lang.String")).call(",");
                forMethod(getField(Class.forName("java.lang.System"), "out"), "println").call();

                setField(object, (String) forMethod(
                    Class.forName("java.lang.reflect.Array"),
                    "get",
                    Class.forName("java.lang.Object"),
                    int.class
                ).call(split, 0), forMethod(
                    Class.forName("java.lang.reflect.Array"),
                    "get",
                    Class.forName("java.lang.Object"),
                    int.class
                ).call(split, 1));
            } else if (lowerCase.equals("g")) {
                forMethod(getField(Class.forName("java.lang.System"), "out"), "print", Class.forName("java.lang.String"))
                    .call("<fieldName>: ");
                forMethod(getField(Class.forName("java.lang.System"), "out"), "println", Class.forName("java.lang.String"))
                    .call(getField(object, (String) forMethod(forMethod(
                        forMethod(
                            (Object) Class.forName("java.util.Scanner"),
                            "getConstructor",
                            (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                           "newInstance",
                                                           Class.forName("java.lang.Class"),
                                                           int.class
                            ).call(Class.forName("java.lang.Class"), 1), "getClass").call()
                        ).call(forMethod(
                            Class.forName("java.lang.reflect.Array"),
                            "newInstance",
                            Class.forName("java.lang.Class"),
                            int.class
                        ).call(
                            Class.forName("java.lang.Class"),
                            1
                        )),
                        "newInstance",
                        (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                       "newInstance",
                                                       Class.forName("java.lang.Class"),
                                                       int.class
                        ).call(Class.forName("java.lang.Object"), 1), "getClass").call()
                    ).call(forMethod(Class.forName("java.lang.reflect.Array"), "newInstance", Class.forName("java.lang.Class"), int.class).call(
                        Class.forName("java.lang.Object"),
                        1
                    )), "nextLine").call()));
                forMethod(getField(Class.forName("java.lang.System"), "out"), "println").call();

            } else if (lowerCase.equals("c")) {
                forMethod(getField(Class.forName("java.lang.System"), "out"), "print", Class.forName("java.lang.String"))
                    .call("<methodName>: ");
                forMethod(object, (String) forMethod(forMethod(
                    forMethod(
                        (Object) Class.forName("java.util.Scanner"),
                        "getConstructor",
                        (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                       "newInstance",
                                                       Class.forName("java.lang.Class"),
                                                       int.class
                        ).call(Class.forName("java.lang.Class"), 1), "getClass").call()
                    ).call(forMethod(
                        Class.forName("java.lang.reflect.Array"),
                        "newInstance",
                        Class.forName("java.lang.Class"),
                        int.class
                    ).call(
                        Class.forName("java.lang.Class"),
                        1
                    )),
                    "newInstance",
                    (Class<?>) forMethod(forMethod(Class.forName("java.lang.reflect.Array"),
                                                   "newInstance",
                                                   Class.forName("java.lang.Class"),
                                                   int.class
                    ).call(Class.forName("java.lang.Object"), 1), "getClass").call()
                ).call(forMethod(Class.forName("java.lang.reflect.Array"), "newInstance", Class.forName("java.lang.Class"), int.class).call(
                    Class.forName("java.lang.Object"),
                    1
                )), "nextLine").call()).call();
                forMethod(getField(Class.forName("java.lang.System"), "out"), "println").call();
            }
        }
    }


    //****************************************************************************************
    // Framework
    //****************************************************************************************
    public static class MethodCaller {
        private final Class<?> aClass;
        private final Object object;
        private final String method;
        private final Class<?>[] types;

        public MethodCaller(Class<?> aClass, Object object, String method, Class<?>[] types) throws Throwable {
            this.aClass = aClass;
            this.object = object;
            this.method = method;
            this.types = types;
        }

        public Object call(Object... params) throws Throwable {
            Method method;
            try {
                method = aClass.getDeclaredMethod(this.method, types);
            } catch (NoSuchMethodException e) {
                method = aClass.getMethod(this.method, types);
            }
            method.setAccessible(true);
            return method.invoke(object, params);
        }
    }

    public static MethodCaller forMethod(Class<?> aClass, String method, Class<?>... types) throws Throwable {
        return new MethodCaller(aClass, null, method, types);
    }

    public static MethodCaller forMethod(Object object, String method, Class<?>... types) throws Throwable {
        final Class<?> aClass = object.getClass();
        return new MethodCaller(aClass, object, method, types);
    }

    public static Object getField(Class<?> aClass, String fieldName) throws Throwable {
        Field field;
        try {
            field = aClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            field = aClass.getField(fieldName);
        }
        field.setAccessible(true);
        return field.get(null);
    }

    public static Object getField(Object object, String fieldName) throws Throwable {
        final Class<?> aClass = object.getClass();
        Field field;
        try {
            field = aClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            field = aClass.getField(fieldName);
        }
        field.setAccessible(true);
        return field.get(object);
    }

    public static Object setField(Class<?> aClass, String fieldName, Object value) throws Throwable {
        Field field;
        try {
            field = aClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            field = aClass.getField(fieldName);
        }
        field.setAccessible(true);
        if (Modifier.isFinal(field.getModifiers())) {
            final Field modifiers = field.getClass().getDeclaredField("modifiers");
            modifiers.setAccessible(true);
            modifiers.setInt(field, field.getModifiers() & ~Modifier.FINAL);
        }
        final Object oldVal = getField(aClass, fieldName);
        field.set(null, value);
        return oldVal;
    }

    public static Object setField(Object object, String fieldName, Object value) throws Throwable {
        final Class<?> aClass = object.getClass();
        Field field;
        try {
            field = aClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            field = aClass.getField(fieldName);
        }
        field.setAccessible(true);
        if (Modifier.isFinal(field.getModifiers())) {
            final Field modifiers = field.getClass().getDeclaredField("modifiers");
            modifiers.setAccessible(true);
            modifiers.setInt(field, field.getModifiers() & ~Modifier.FINAL);
        }
        final Object oldVal = getField(object, fieldName);
        field.set(object, value);
        return oldVal;
    }
}