src/server/plugins/java/javasrc/webserver/ServerPlugin.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2013 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package webserver;

import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import webserver.nsapi.Module;
import webserver.nsapi.PBlock;
import webserver.nsapi.Request;
import webserver.nsapi.SAF;
import webserver.nsapi.Session;

class ServerPlugin {
    private ArrayList<ServerFunction> registeredFunctions = new ArrayList<>(32);

    public ServerPlugin() {
        
    }

    public native void addMethod(String name, int safIndex);

    static {
        System.loadLibrary("nsapi_jni");
    }

    public int loadModule(String jar, String classes) {
            System.out.println("load-jmodule jar=\""+jar+"\" classes=\""+classes+"\"");

            File jarFile = new File(jar);
            if(!jarFile.exists()) {
                System.err.println("jar file does not exist");
                return -1;
            }
        try {                
            URL[] urls = new URL[]{jarFile.toURI().toURL()};
            URLClassLoader cl = new URLClassLoader(urls, this.getClass().getClassLoader());

            for(String className : classes.split(",")) {
                Class moduleClass = Class.forName(className, true, cl);
                loadClass(moduleClass);
            }
        } catch (MalformedURLException e) {
            System.err.println("ServerPlugin.loadModule: "+e);
            return -1;
        } catch (ClassNotFoundException e) {
            System.err.println("Java Module Class not found: "+e);
            return -1;
        } catch (InstantiationException e) {
            System.err.println("ServerPlugin.loadModule: "+e);
            return -1;
        } catch (IllegalAccessException e) {
            System.err.println("ServerPlugin.loadModule: "+e);
            return -1;
        }

        System.out.println("Java Module loaded");
        return 0;
    }

    public void loadClass(Class cl) throws InstantiationException, IllegalAccessException {
        Module module = (Module)cl.getAnnotation(Module.class);
        if(module == null) {
            System.err.println("Missing Module annotation for class: "+cl.getCanonicalName());
            return;
        }

        Object moduleInstance = cl.newInstance();
        for(Method m : cl.getMethods()) {
            if(isSAF(m)) {
                SAF saf = m.getAnnotation(SAF.class);
                if(saf.init()) {

                }
                if(saf.name().length() > 0) {
                    ServerFunction f = new ServerFunction();
                    f.module = moduleInstance;
                    f.method = m;

                    String safName = module.name() + "." + saf.name();
                    registeredFunctions.add(f);
                    int index = registeredFunctions.lastIndexOf(f);
                    addMethod(safName, index);
                }
            }
        }
    }

    private boolean isSAF(Method m) {
        SAF saf = m.getAnnotation(SAF.class);
        if(saf != null) {
            // check method signature
            if(m.getReturnType() != int.class) {
                System.err.println("wrong return type for SAF: "+m.getName());
                return false;
            }
            Class paramTypes[] = m.getParameterTypes();
            if(paramTypes.length != 3) {
                System.err.println("wrong number of parameters for SAF: "+m.getName());
                return false;
            }
            if(paramTypes[0] != PBlock.class) {
                System.err.println("wrong method signature for SAF: "+m.getName());
                return false;
            }
            if(paramTypes[1] != Session.class) {
                System.err.println("wrong method signature for SAF: "+m.getName());
                return false;
            }
            if(paramTypes[2] != Request.class) {
                System.err.println("wrong method signature for SAF: "+m.getName());
                return false;
            }
            return true;
        }
        return false;
    }
    
    public int exec(int safIndex) {
        System.out.println("(Java) exec: "+safIndex);
        ServerFunction saf = registeredFunctions.get(safIndex);
        if(saf == null) {
            return -1;
        }
        Integer ret = new Integer(-1);
        try {
            ret = (Integer)saf.method.invoke(saf.module, null, null, null);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        return ret.intValue();
    }
}