org.mvel2.sh.command.basic.ObjectInspector Maven / Gradle / Ivy

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/**
 * MVEL 2.0
 * Copyright (C) 2007 The Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.mvel2.sh.command.basic;

import static org.mvel2.sh.text.TextUtil.padTwo;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.LinkedList;
import java.util.List;

import org.mvel2.sh.Command;
import org.mvel2.sh.ShellSession;
import org.mvel2.sh.text.TextUtil;
import org.mvel2.util.StringAppender;

public class ObjectInspector implements Command {

    private static final int PADDING = 17;

    private static String renderClassHeirarchy(Class cls) {
        List list = new LinkedList();
        list.add(cls.getName());

        while ((cls = cls.getSuperclass()) != null) {
            list.add(cls.getName());
        }

        StringAppender output = new StringAppender();

        for (int i = list.size() - 1; i != -1; i--) {
            output.append(list.get(i));
            if ((i - 1) != -1) output.append(" -> ");
        }

        return output.toString();
    }

    private static void renderFields(Class cls) {
        Field[] fields = cls.getFields();

        for (int i = 0; i < fields.length; i++) {
            write("", fields[i].getType().getName() + " " + fields[i].getName());
        }
    }

    private static void renderMethods(Class cls) {
        Method[] methods = cls.getMethods();

        Method m;
        StringAppender appender = new StringAppender();
        int mf;
        for (int i = 0; i < methods.length; i++) {
            appender.append(TextUtil.paint(' ', PADDING + 2));
            if (((mf = (m = methods[i]).getModifiers()) & Modifier.PUBLIC) != 0) appender.append("public");
            else if ((mf & Modifier.PRIVATE) != 0) appender.append("private");
            else if ((mf & Modifier.PROTECTED) != 0) appender.append("protected");

            appender.append(' ').append(m.getReturnType().getName()).append(' ').append(m.getName()).append("(");
            Class[] parmTypes = m.getParameterTypes();
            for (int y = 0; y < parmTypes.length; y++) {
                if (parmTypes[y].isArray()) {
                    appender.append(parmTypes[y].getComponentType().getName() + "[]");
                } else {
                    appender.append(parmTypes[y].getName());
                }
                if ((y + 1) < parmTypes.length) appender.append(", ");
            }
            appender.append(")");

            if (m.getDeclaringClass() != cls) {
                appender.append("    [inherited from: ").append(m.getDeclaringClass().getName()).append("]");
            }

            if ((i + 1) < methods.length) appender.append('\n');
        }

        System.out.println(appender.toString());
    }

    private static void write(Object first, Object second) {
        System.out.println(padTwo(first, ": " + second, PADDING));
    }

    public Object execute(ShellSession session, String[] args) {

        if (args.length == 0) {
            System.out.println("inspect: requires an argument.");
            return null;
        }

        if (!session.getVariables().containsKey(args[0])) {
            System.out.println("inspect: no such variable: " + args[0]);
            return null;
        }

        Object val = session.getVariables().get(args[0]);

        System.out.println("Object Inspector");
        System.out.println(TextUtil.paint('-', PADDING));

        if (val == null) {
            System.out.println("[Value is Null]");
            return null;
        }

        Class cls = val.getClass();
        boolean serialized = true;
        long serializedSize = 0;

        try {
            ByteArrayOutputStream outStream = new ByteArrayOutputStream();
            ObjectOutputStream objectOut = new ObjectOutputStream(new BufferedOutputStream(outStream));
            objectOut.writeObject(val);
            objectOut.flush();
            outStream.flush();

            serializedSize = outStream.size();
        } catch (Exception e) {
            serialized = false;
        }

        write("VariableName", args[0]);
        write("Hashcode", val.hashCode());
        write("ClassType", cls.getName());
        write("Serializable", serialized);
        if (serialized) {
            write("SerializedSize", serializedSize + " bytes");
        }
        write("ClassHierarchy", renderClassHeirarchy(cls));
        write("Fields", cls.getFields().length);
        renderFields(cls);

        write("Methods", cls.getMethods().length);
        renderMethods(cls);

        System.out.println();

        return null;
    }

    public String getDescription() {
        return "inspects an object";
    }

    public String getHelp() {
        return "No help yet";
    }
}