ClassFile.java

/*
 *   
 *
 * Copyright  1990-2009 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 * 
 * This program 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.
 * 
 * This program 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 at /legal/license.txt).
 * 
 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 */

package util;

import components.*;

import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.IOException;
import java.io.PrintStream;
import java.io.InputStream;

import java.util.Enumeration;
import java.util.Hashtable;
import jcc.Const;

/*
 * Reading of class files.
 * Which is different from reading a class from a multi-class file.
 * But not much.
 * Much of the real work is done in components.ClassInfo.
 *
 * There would be stuff for writing class files here, too, but we've
 * never been called upon to do that operation.
 *
 * Also includes a small test program for reading and dumping
 * a class file.
 */

public
class ClassFile
{
    // Input file name
    public String 	fileName;
    public boolean 	didRead = false;
    public Exception 	failureMode; // only for didRead == false.
    public boolean	verbose = false;
    public ClassInfo	clas;
    PrintStream   	log = System.out;
    InputStream		istream;

    // Identifies the classfile format
    int			minorID,
			majorID;

    public ClassFile(String name, boolean v ) {
	fileName = name;
	verbose	 = v;
	clas     = new ClassInfo( v );
	istream  = null;
    }

    public ClassFile(String name, InputStream i, boolean v ) {
	fileName = name;
	verbose	 = v;
	clas     = new ClassInfo( v );
	istream  = i;
    }

    // Read in the entire class file
    public boolean
    readClassFile( ConstantPool t ) {
	DataInputStream in = null;
	failureMode = null;
    done:
	try {
	    int magic;
	    if ( istream == null ){
		istream = new java.io.BufferedInputStream( new java.io.FileInputStream( fileName ) );
	    }
	    in = new DataInputStream( istream );
	    if ((magic = in.readInt()) != Const.JAVA_MAGIC) {
		failureMode = new IOException(Localizer.getString("classfile.bad_magic.ioexception"));
		break done; // bad magic -- bail immediately.
	    }

	    minorID = in.readShort();
	    majorID = in.readShort();
	    //if (minorID != Const.JAVA_MINOR_VERSION) {
	    //	failureMode = new IOException(Localizer.getString("classfile.bad_minor_version_number.ioexception"));
	    //	break done; // bad magic -- bail immediately.
	    //}
            //
	    //if (majorID != Const.JAVA_VERSION) {
	    //	failureMode = new IOException(Localizer.getString("classfile.bad_major_version_number.ioexception"));
	    //	break done; // bad magic -- bail immediately.
	    //}
	    if(verbose){
		log.println(Localizer.getString("classfile._file", fileName)+
			    Localizer.getString("classfile._magic/major/minor",
		                                Integer.toHexString( magic ),
		                                Integer.toHexString( majorID ),
		                                Integer.toHexString( minorID )));
	    }
	    clas.read( in, true, t );
	    didRead = true;
	} catch ( Exception e ){
	    failureMode = e;
	}
	if ( in != null ){
	    try{
		in.close();
	    } catch ( IOException e ){
		if (didRead==true){
		    didRead=false;
		    failureMode=e;
		}
	    }
	}
	return didRead;
    }

    public void
    dump( PrintStream o ){
	o.println(Localizer.getString("classfile.file", fileName));
	if ( ! didRead ){
	    o.println(Localizer.getString(
			  "classfile.could_not_be_read_because_of", 
			  failureMode));
	    if ( failureMode != null ) // IMPL_NOTE: consider whether this
                                       // should be fixed 
		failureMode.printStackTrace( o );
	    return;
	}
	clas.dump( o );
    }

    /*
     * Simple test program.
     * Parameters: list of class files to read and process.
     */
    public static void main( String clist[] ){
	for( int i = 0; i < clist.length; i++ ){
	    ClassFile f = new ClassFile( clist[i], true );
	    if (f.readClassFile( null ) != true ){
		System.out.println(Localizer.getString(
				        "classfile.read_of",
				        clist[i]));
		f.dump( System.out );
		continue;
	    }
	    f.clas.countReferences( true );
	    f.dump( System.out );
	}
    }

}