org.gololang.webconsole.RunServlet.java Source code

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Here is the source code for org.gololang.webconsole.RunServlet.java

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/*
 * Copyright (C) 2013 Julien Ponge
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package org.gololang.webconsole;

import com.google.appengine.api.capabilities.Capability;
import com.google.apphosting.api.ApiProxy;
import com.google.apphosting.api.ApiProxy.ApiConfig;
import com.google.apphosting.api.ApiProxy.ApiProxyException;
import com.google.apphosting.api.ApiProxy.Delegate;
import com.google.apphosting.api.ApiProxy.Environment;
import com.google.apphosting.api.ApiProxy.LogRecord;
import com.google.common.base.Charsets;
import com.google.common.io.CharStreams;
import org.eclipse.golo.compiler.GoloClassLoader;
import org.eclipse.golo.compiler.GoloCompilationException;
import org.eclipse.golo.compiler.parser.TokenMgrError;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.reflect.Field;
import java.util.HashSet;
import java.util.List;
import java.util.concurrent.Future;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RunServlet extends HttpServlet {

    public static class Context {

        private StringBuilder builder = new StringBuilder();

        public Context log(Object obj) {
            builder.append(obj).append("\n");
            return this;
        }
    }

    @Override
    public void init() throws ServletException {
        super.init();
        final HashSet<String> forbidden = new HashSet<String>() {
            {
                for (Field field : Capability.class.getFields()) {
                    if (field.getType() == Capability.class) {
                        try {
                            Capability cap = (Capability) field.get(null);
                            add(cap.getPackageName());
                        } catch (IllegalArgumentException | IllegalAccessException ex) {
                            throw new ServletException(ex);
                        }
                    }
                }
            }
        };
        final Delegate delegate = ApiProxy.getDelegate();
        ApiProxy.setDelegate(new Delegate() {

            @Override
            public byte[] makeSyncCall(Environment env, String packageName, String methodName, byte[] request)
                    throws ApiProxyException {
                if (forbidden.contains(packageName)) {
                    throw new ApiProxyException("Access to " + packageName + " is forbidden");
                }
                return delegate.makeSyncCall(env, packageName, methodName, request);
            }

            @Override
            public Future makeAsyncCall(Environment env, String packageName, String methodName, byte[] request,
                    ApiConfig config) {
                if (forbidden.contains(packageName)) {
                    throw new ApiProxyException("Access to " + packageName + " is forbidden");
                }
                return delegate.makeAsyncCall(env, packageName, methodName, request, config);
            }

            @Override
            public void log(Environment env, LogRecord record) {
                delegate.log(env, record);
            }

            @Override
            public void flushLogs(Environment env) {
                delegate.flushLogs(env);
            }

            @Override
            public List getRequestThreads(Environment env) {
                return delegate.getRequestThreads(env);
            }
        });
    }

    private void run(String code, HttpServletResponse response) throws ServletException, IOException {
        try (ByteArrayInputStream codeStream = new ByteArrayInputStream(code.getBytes())) {
            GoloClassLoader classLoader = new GoloClassLoader(RunServlet.class.getClassLoader());
            Class<?> module = classLoader.load("test.golo", codeStream);
            try {
                Context context = new Context();
                context.log("-> run returned: " + module.getMethod("run", Object.class).invoke(null, context));
                response.getWriter().write(context.builder.toString());
            } catch (Throwable t) {
                if (t.getMessage() == null) {
                    response.getWriter().write(t.getCause().toString());
                }
            }
        } catch (GoloCompilationException e) {
            if (e.getCause() != null) {
                response.getWriter().write(e.getCause().getMessage() + "\n");
            }
            for (GoloCompilationException.Problem problem : e.getProblems()) {
                response.getWriter().write(problem.getDescription() + "\n");
            }
        } catch (TokenMgrError e) {
            response.getWriter().write(e.getMessage() + "\n");
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/plain");
        try (InputStreamReader reader = new InputStreamReader(request.getInputStream(), Charsets.UTF_8)) {
            String code = CharStreams.toString(reader);
            run(code, response);
        }
    }

}