proxybuilder.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-@year@ by SMB GmbH. All rights reserved.
//
// $Id$
package org.ozoneDB.tools.OPP.srcgen.builder;

import org.ozoneDB.tools.OPP.OPPHelper;
import org.ozoneDB.tools.OPP.srcgen.ClassBuilder;
import org.ozoneDB.tools.OPP.srcgen.BuilderException;
import org.ozoneDB.tools.OPP.srcgen.streamfactory.OutputStreamFactory;
import org.ozoneDB.tools.OPP.message.MessageWriter;
import org.ozoneDB.OzoneRemote;
import org.ozoneDB.core.helper.ReflectionHelper;
import org.ozoneDB.core.Lock;

import java.io.*;
import java.util.*;
import java.lang.reflect.Method;

/**
 * Builds an ozone Proxy. The code is lifted out of the proxy generator
 * and adapted to the builder director pattern.
 *
 * A lot oof code changes has to do with the absence of reflection dependency in the implementation of the builder
 * director pattern implementation. The proxy builder still depends heavily on reflection, something that could
 * probably be dealt with. The changes we have now is a lot of String lookup functionality for classes.
 *
 * We'd like to support static inner classes as OzoneObjects, but where should the proxy classes be defined?
 * Within the the proxy class of the enclosing class? If so, what if the enclosing class is not OzoneCompatible?
 *
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @author <a href="http://www.medium.net/">Medium.net</a>
 * @author Per Nyfelt
 * @author Joakim Ohlrogge
 */
public class ProxyBuilder implements ClassBuilder {
    private PrintWriter out;
    private OutputStreamFactory osFactory;
    private String postfix;
    private Collection remoteInterfaces = new HashSet();
    private boolean printStackTrace;
    private boolean cache;
    private MessageWriter msgWriter;
    private String className;
    private String proxyClassName;
    private Class implementationClass;
    private Method sortedMethods[];

    private int getMethodIndex(String method, ClassBuilder.Parameter parameters[]) throws ClassNotFoundException, NoSuchMethodException {
        Method m = implementationClass.getMethod(method, parametersToClasses(parameters));
        return ReflectionHelper.methodArrayIndex(sortedMethods, m);
    }

    private Class[] parametersToClasses(ClassBuilder.Parameter parameters[]) throws ClassNotFoundException {
        Class params[] = new Class[parameters.length];
        for (int i = 0; i < parameters.length; i++) {
            ClassBuilder.Parameter parameter = parameters[i];
            params[i] = getClassForType(parameter.getOrigTypeName());
        }
        return params;
    }

    private Class getClassForType(String type) throws ClassNotFoundException {
        Class clType = OPPHelper.classForPrimitive(type);
        if (clType == null) {
            Class cl = Class.forName(type);
            return cl;
        } else
            return clType;
    }

    public ProxyBuilder(OutputStreamFactory osFactory, String postfix, boolean printStackTrace, boolean cache, MessageWriter listener) {
        this.osFactory = osFactory;
        this.postfix = postfix;
        this.printStackTrace = printStackTrace;
        this.cache = cache;
        this.msgWriter = listener;
    }

    private String[] getTypes(ClassBuilder.Parameter parameters[]) {
        String types[] = new String[parameters.length];
        for (int i = 0; i < parameters.length; i++) {
            ClassBuilder.Parameter parameter = parameters[i];
            types[i] = parameter.getType();
        }
        return types;
    }

    private void makeCtrs() {
        out.print("\n");
        out.print("   public " + OPPHelper.simpleClassName(proxyClassName) + "() {\n");
        out.print("      super();\n");

        //       out.print ("      System.out.println (\"Ctor...\");\n");

        //       out.print ("      new Exception().fillInStackTrace().printStackTrace();\n");

        out.print("   }\n");
        out.print("\n\n");



        // create default ctor that is responsible to create a pure proxy

        // without interacting with any database

        out.print("   public " + OPPHelper.simpleClassName(proxyClassName) + " (ObjectID oid,OzoneInterface link) {\n");
        out.print("      super(oid,link);\n");
        out.print("   }\n");
    }

    private void makeGlobalHeader(String implementationClass) {
        out.print("// Proxy class generated by ozone's OPP ($Revision$).\n");
        out.print("// DO NOT EDIT!\n");
        out.print("\n");
        if (!OPPHelper.packageName(implementationClass).equals("")) {
            out.print("package " + OPPHelper.packageName(implementationClass) + ";\n");
            out.print("\n");
        }
        out.print("import org.ozoneDB.*;\n");
        out.print("import org.ozoneDB.core.ObjectID;\n");
        out.print("import org.ozoneDB.core.Lock;\n");
        out.print("import org.ozoneDB.core.ResultConverter;\n");
    }

    private void makeLocalHeader(String proxyClassName) {
        out.print("\n");
        out.print("/**\n");
        out.print(" * This class was automatically generated by ozone's OPP.\n");
        out.print(" * Do not instantiate or use this class directly.\n");
        out.print(" */\n");
        out.print("public final class " + OPPHelper.simpleClassName(proxyClassName) + " extends OzoneProxy");
        boolean first = true;
        for (Iterator iter = remoteInterfaces.iterator(); iter.hasNext();) {
            // filter methods that are not inherited from a OzoneRemote
            // interface
            if (first) {
                first = false;
                out.print(" implements ");
            } else {
                out.print(", ");
            }
            out.print(((Class) iter.next()).getName());
        }
        out.print(" {\n");
        out.print("\n   static final long	serialVersionUID = 1L;\n");
    }

    private void makeCstr(ClassBuilder.Parameter[] parameters, String[] exceptions) {
        // string buffer to build the signatur of this method

        StringBuffer signaturBuf = new StringBuffer("");
        signaturBuf.append("   public " + OPPHelper.simpleClassName(proxyClassName) + " (");

        // write the arguments in the declaration

        // skip default ctor
        if (parameters.length == 0) {
            return;
        }
        for (int i = 0; i < parameters.length; i++) {
            if (i != 0) {
                signaturBuf.append(", ");
            }
            signaturBuf.append(parameters[i].getType() + " " + parameters[i].getName());
        }
        signaturBuf.append(")");
        out.print("\n\n");
        out.print(signaturBuf.toString());



        //Write the exceptions in the declaration
        for (int i = 0; i < exceptions.length; i++) {
            out.print(i == 0 ? " throws " : ", ");
            out.print(exceptions[i]);
        }
        out.print(" {\n");



        // the actual code of the method
        out.print("      try {\n");
        out.print("         link = ExternalDatabase.forThread (Thread.currentThread());\n");
        out.print("         if (link == null)\n");
        out.print("            throw new TransactionException (\"Thread has not yet joined a transaction.\");\n");
        out.print("         \n");



        //array of arguments
        out.print("         Object[] args = {");
        for (int i = 0; i < parameters.length; i++) {
            out.print(i > 0 ? ", " : "");
            if (OPPHelper.isPrimitive(parameters[i].getType())) {
                out.print("new " + OPPHelper.wrappercodeForPrimitive(parameters[i].getType()) + "(arg" + i + ")");
            } else {
                out.print("arg" + i);
            }
        }
        out.print("};\n");
        String sig = ReflectionHelper.signature(getTypes(parameters));
        out.print("         OzoneProxy proxy = link.createObject (\"" + className
                + "_Impl\", OzoneInterface.Public, null, " + sig + ", args);\n");
        out.print("         remoteID = proxy.remoteID();\n");
        out.print("         }\n");


        //exceptions
        boolean alreadyCatched = false;
        for (int i = 0; i < exceptions.length; i++) {
            out.print("      catch (" + exceptions[i] + " e) {\n");
            out.print("         e.fillInStackTrace();\n");
            out.print("         throw e; }\n");

            // out.print ("         throw (" + excs[i].getName() + ")e.fillInStackTrace(); }\n");

            if (exceptions[i].equals("build.lang.Exception")) {
                alreadyCatched = true;
            }
        }
        if (!alreadyCatched) {
            out.print("      catch (Exception e) {\n");
            if (printStackTrace) {
                out.print("         e.printStackTrace (System.out);\n");
            }
            out.print("         e.fillInStackTrace();\n");
            out.print("         throw new UnexpectedException(e.toString()); }\n");
        }
        out.print("   }\n");
    }

    private void makeCreateMethod(ClassBuilder.Parameter[] parameters, String[] exceptions) {
        // string buffer to build the signature of this method

        StringBuffer signaturBuf = new StringBuffer("");
        signaturBuf.append("   public static ");
        Class firstItf = (Class) remoteInterfaces.iterator().next();
        String proxyInterface = firstItf.getName();
        signaturBuf.append(proxyInterface);
        signaturBuf.append(" createObject(");

        // argumente in declaration schreiben

        for (int i = 0; i < parameters.length; i++) {
            if (i != 0) {
                signaturBuf.append(", ");
            }
            signaturBuf.append(parameters[i].getType() + " " + parameters[i].getName());
        }
        if (parameters.length != 0) {
            signaturBuf.append(",");
        }
        signaturBuf.append("OzoneInterface link)");
        out.print("\n\n");
        out.print(signaturBuf.toString());



        //exceptions in declaration schreiben


        for (int i = 0; i < exceptions.length; i++) {
            out.print(i == 0 ? " throws " : ", ");
            out.print(exceptions[i]);
        }
        out.print(" {\n");



        // the actual code of the method

        out.print("      try {\n");
        out.print("         /*\n");
        out.print("            if (link == null)\n");
        out.print("               throw new TransactionException (\"Thread has not yet joined a transaction.\");\n");
        out.print("         */\n");
        out.print("         \n");



        //array of arguments

        out.print("         Object[]   args  = {");
        for (int i = 0; i < parameters.length; i++) {
            out.print(i > 0 ? ", " : "");
            if (OPPHelper.isPrimitive(parameters[i].getType())) {
                out.print("new " + OPPHelper.wrappercodeForPrimitive(parameters[i].getType()) + "(arg" + i + ")");
            } else {
                out.print("arg" + i);
            }
        }
        out.print("};\n");
        String sig = ReflectionHelper.signature(getTypes(parameters));
        out.print("         OzoneProxy proxy = link.createObject (\"" + className
                + "\", OzoneInterface.Public, null, " + sig + ", args);\n");
        out.print("         \n");
        out.print("         return (" + proxyInterface + ") proxy;\n");



        //exceptions

        boolean catchedRuntimeException = false;
        boolean catchedOzoneRemoteException = false;
        if (false) {
            for (int i = 0; i < exceptions.length; i++) {
                out.print("      } catch (" + exceptions[i] + " e) {\n");
                out.print("         e.fillInStackTrace();\n");
                out.print("         throw e;\n");