alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (ValueType.java)

This example Java source code file (ValueType.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

batchenvironment, classdeclaration, classdefinition, classnotfound, contextstack, custom, hashtable, memberdefinition, objectstreamclass, string, tm_class, type, util, valuetype, vector

The ValueType.java Java example source code

/*
 * Copyright (c) 1998, 2007, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
/*
 * Licensed Materials - Property of IBM
 * RMI-IIOP v1.0
 * Copyright IBM Corp. 1998 1999  All Rights Reserved
 *
 */

package sun.rmi.rmic.iiop;

import java.util.Vector;
import sun.tools.java.ClassNotFound;
import sun.tools.java.ClassDeclaration;
import sun.tools.java.ClassDefinition;
import sun.tools.java.MemberDefinition;
import java.util.Hashtable;
import java.io.ObjectStreamClass;
import java.io.ObjectStreamField;


/**
 * ValueType represents any non-special class which does inherit from
 * java.io.Serializable and does not inherit from java.rmi.Remote.
 * <p>
 * The static forValue(...) method must be used to obtain an instance, and
 * will return null if the ClassDefinition is non-conforming.
 *
 * @author      Bryan Atsatt
 */
public class ValueType extends ClassType {

    private boolean isCustom;

    //_____________________________________________________________________
    // Public Interfaces
    //_____________________________________________________________________

    /**
     * Create an ValueType object for the given class.
     *
     * If the class is not a properly formed or if some other error occurs, the
     * return value will be null, and errors will have been reported to the
     * supplied BatchEnvironment.
     */
    public static ValueType forValue(ClassDefinition classDef,
                                     ContextStack stack,
                                     boolean quiet) {

        if (stack.anyErrors()) return null;

        // Do we already have it?

        sun.tools.java.Type theType = classDef.getType();
        String typeKey = theType.toString();
        Type existing = getType(typeKey,stack);

        if (existing != null) {

            if (!(existing instanceof ValueType)) return null; // False hit.

            // Yep, so return it...

            return (ValueType) existing;
        }

        // Is this java.lang.Class?

        boolean javaLangClass = false;

        if (classDef.getClassDeclaration().getName() == idJavaLangClass) {

            // Yes, so replace classDef with one for
            // javax.rmi.CORBA.ClassDesc...

            javaLangClass = true;
            BatchEnvironment env = stack.getEnv();
            ClassDeclaration decl = env.getClassDeclaration(idClassDesc);
            ClassDefinition def = null;

            try {
                def = decl.getClassDefinition(env);
            } catch (ClassNotFound ex) {
                classNotFound(stack,ex);
                return null;
            }

            classDef = def;
        }

        // Could this be a value?

        if (couldBeValue(stack,classDef)) {

            // Yes, so check it...

            ValueType it = new ValueType(classDef,stack,javaLangClass);
            putType(typeKey,it,stack);
            stack.push(it);

            if (it.initialize(stack,quiet)) {
                stack.pop(true);
                return it;
            } else {
                removeType(typeKey,stack);
                stack.pop(false);
                return null;
            }
        } else {
            return null;
        }
    }


    /**
     * Return a string describing this type.
     */
    public String getTypeDescription () {
        String result = addExceptionDescription("Value");
        if (isCustom) {
            result = "Custom " + result;
        }
        if (isIDLEntity) {
            result = result + " [IDLEntity]";
        }
        return result;
    }

    /**
     * Return true if this type is a "custom" type (i.e.
     * it implements java.io.Externalizable or has a
     * method with the following signature:
     *
     *  private void writeObject(java.io.ObjectOutputStream out);
     *
     */
    public boolean isCustom () {
        return isCustom;
    }


    //_____________________________________________________________________
    // Subclass/Internal Interfaces
    //_____________________________________________________________________

    /**
     * Create a ValueType instance for the given class.  The resulting
     * object is not yet completely initialized.
     */
    private ValueType(ClassDefinition classDef,
                      ContextStack stack,
                      boolean isMappedJavaLangClass) {
        super(stack,classDef,TYPE_VALUE | TM_CLASS | TM_COMPOUND);
        isCustom = false;

        // If this is the mapped version of java.lang.Class,
        // set the non-IDL names back to java.lang.Class...

        if (isMappedJavaLangClass) {
            setNames(idJavaLangClass,IDL_CLASS_MODULE,IDL_CLASS);
        }
    }

    //_____________________________________________________________________
    // Internal Interfaces
    //_____________________________________________________________________

    /**
     * Initialize this instance.
     */

    private static boolean couldBeValue(ContextStack stack, ClassDefinition classDef) {

        boolean result = false;
        ClassDeclaration classDecl = classDef.getClassDeclaration();
        BatchEnvironment env = stack.getEnv();

        try {
            // Make sure it's not remote...

            if (env.defRemote.implementedBy(env, classDecl)) {
                failedConstraint(10,false,stack,classDef.getName());
            } else {

                // Make sure it's Serializable...

                if (!env.defSerializable.implementedBy(env, classDecl)) {
                    failedConstraint(11,false,stack,classDef.getName());
                } else {
                    result = true;
                }
            }
        } catch (ClassNotFound e) {
            classNotFound(stack,e);
        }

        return result;
    }

    /**
     * Initialize this instance.
     */
    private boolean initialize (ContextStack stack, boolean quiet) {

        ClassDefinition ourDef = getClassDefinition();
        ClassDeclaration ourDecl = getClassDeclaration();

        try {

            // Make sure our parentage is ok...

            if (!initParents(stack)) {
                failedConstraint(12,quiet,stack,getQualifiedName());
                return false;
            }


            // We're ok, so make up our collections...

            Vector directInterfaces = new Vector();
            Vector directMethods = new Vector();
            Vector directMembers = new Vector();

            // Get interfaces...

            if (addNonRemoteInterfaces(directInterfaces,stack) != null) {

                // Get methods...

                if (addAllMethods(ourDef,directMethods,false,false,stack) != null) {

                    // Update parent class methods
                    if (updateParentClassMethods(ourDef,directMethods,false,stack) != null) {

                    // Get constants and members...

                    if (addAllMembers(directMembers,false,false,stack)) {

                        // We're ok, so pass 'em up...

                        if (!initialize(directInterfaces,directMethods,directMembers,stack,quiet)) {
                            return false;
                        }

                        // Is this class Externalizable?

                        boolean externalizable = false;
                        if (!env.defExternalizable.implementedBy(env, ourDecl)) {

                            // No, so check to see if we have a serialPersistentField
                            // that will modify the members.

                            if (!checkPersistentFields(getClassInstance(),quiet)) {
                                return false;
                            }
                        } else {

                            // Yes.

                            externalizable = true;
                        }

                        // Should this class be considered "custom"? It is if
                        // it is Externalizable OR if it has a method with the
                        // following signature:
                        //
                        //  private void writeObject(java.io.ObjectOutputStream out);
                        //

                        if (externalizable) {
                            isCustom = true;
                        } else {
                            for (MemberDefinition member = ourDef.getFirstMember();
                                 member != null;
                                 member = member.getNextMember()) {

                                if (member.isMethod() &&
                                    !member.isInitializer() &&
                                    member.isPrivate() &&
                                    member.getName().toString().equals("writeObject")) {

                                    // Check return type, arguments and exceptions...

                                    sun.tools.java.Type methodType = member.getType();
                                    sun.tools.java.Type rtnType = methodType.getReturnType();

                                    if (rtnType == sun.tools.java.Type.tVoid) {

                                        // Return type is correct. How about arguments?

                                        sun.tools.java.Type[] args = methodType.getArgumentTypes();
                                        if (args.length == 1 &&
                                            args[0].getTypeSignature().equals("Ljava/io/ObjectOutputStream;")) {

                                            // Arguments are correct, so it is a custom
                                            // value type...

                                            isCustom = true;
                                        }
                                    }
                                }
                            }
                        }
                        }

                        return true;
                    }
                }
            }
        } catch (ClassNotFound e) {
            classNotFound(stack,e);
        }

        return false;
    }


    private boolean checkPersistentFields (Class clz, boolean quiet) {

        // Do we have a writeObject method?

        for (int i = 0; i < methods.length; i++) {
            if (methods[i].getName().equals("writeObject") &&
                methods[i].getArguments().length == 1) {

                Type returnType = methods[i].getReturnType();
                Type arg = methods[i].getArguments()[0];
                String id = arg.getQualifiedName();

                if (returnType.isType(TYPE_VOID) &&
                    id.equals("java.io.ObjectOutputStream")) {

                    // Got one, so there's nothing to do...

                    return true;
                }
            }
        }

        // Do we have a valid serialPersistentField array?

        MemberDefinition spfDef = null;

        for (int i = 0; i < members.length; i++) {
            if (members[i].getName().equals("serialPersistentFields")) {

                Member member = members[i];
                Type type = member.getType();
                Type elementType = type.getElementType();

                // We have a member with the correct name. Make sure
                // we have the correct signature...

                if (elementType != null &&
                    elementType.getQualifiedName().equals(
                                                          "java.io.ObjectStreamField")
                    ) {

                    if (member.isStatic() &&
                        member.isFinal() &&
                        member.isPrivate()) {

                        // We have the correct signature

                        spfDef = member.getMemberDefinition();

                    } else {

                        // Bad signature...

                        failedConstraint(4,quiet,stack,getQualifiedName());
                        return false;
                    }
                }
            }
        }

        // If we do not have a serialPersistentField,
        // there's nothing to do, so return with no error...

        if (spfDef == null) {
            return true;
        }

        // Ok, now we must examine the contents of the array -
        // then validate them...

        Hashtable fields = getPersistentFields(clz);
        boolean result = true;

        for (int i = 0; i < members.length; i++) {
            String fieldName = members[i].getName();
            String fieldType = members[i].getType().getSignature();

            // Is this field present in the array?

            String type = (String) fields.get(fieldName);

            if (type == null) {

                // No, so mark it transient...

                members[i].setTransient();

            } else {

                // Yes, does the type match?

                if (type.equals(fieldType)) {

                    // Yes, so remove it from the fields table...

                    fields.remove(fieldName);

                } else {

                    // No, so error...

                    result = false;
                    failedConstraint(2,quiet,stack,fieldName,getQualifiedName());
                }
            }
        }

        // Ok, we've checked all of our fields. Are there any left in the "array"?
        // If so, it's an error...

        if (result && fields.size() > 0) {

            result = false;
            failedConstraint(9,quiet,stack,getQualifiedName());
        }

        // Return result...

        return result;
    }

    /**
     * Get the names and types of all the persistent fields of a Class.
     */
    private Hashtable getPersistentFields (Class clz) {
        Hashtable result = new Hashtable();
        ObjectStreamClass osc = ObjectStreamClass.lookup(clz);
        if (osc != null) {
            ObjectStreamField[] fields = osc.getFields();
            for (int i = 0; i < fields.length; i++) {
                String typeSig;
                String typePrefix = String.valueOf(fields[i].getTypeCode());
                if (fields[i].isPrimitive()) {
                    typeSig = typePrefix;
                } else {
                    if (fields[i].getTypeCode() == '[') {
                        typePrefix = "";
                    }
                    typeSig = typePrefix + fields[i].getType().getName().replace('.','/');
                    if (typeSig.endsWith(";")) {
                        typeSig = typeSig.substring(0,typeSig.length()-1);
                    }
                }
                result.put(fields[i].getName(),typeSig);
            }
        }
        return result;
    }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java ValueType.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.