source: java/net/deterlab/abac/CredentialFactory.java @ 3612811

package net.deterlab.abac;

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


/**
 * @author <a href="http://abac.deterlab.net">ISI ABAC team</a>
 * @version 1.3
 */
public class CredentialFactory {
    static List<Constructor<? extends Credential> > defCons = 
        new ArrayList<Constructor<? extends Credential> >();
    static List<Constructor<? extends Credential> > cons = 
        new ArrayList<Constructor<? extends Credential> >();
    static String defName = "net.deterlab.abac.GENICredential";
    public static final int maxSize = 50 * 1024;

    static void initDefaultConstructors() throws ABACException {
        try {
            Class c = Class.forName(defName);
            Constructor<?  extends Credential> con = c.getConstructor(
                    Class.forName("java.io.InputStream"),
                    Class.forName("java.util.Collection"));
            defCons.add(con);
        }
        catch (Exception e) {
            throw new ABACException("Could not initialize default " +
                    "credential parser.  Something is very wrong", e);
        }
    }

    static Credential[] newInstance(InputStream is, Set<Identity> ids) 
            throws ABACException {
        Credential rv = null;
        ABACException err = null;
        List<Constructor<? extends Credential> > useCons = 
            (cons.size()> 0 ) ? cons : defCons;

        if ( defCons.size() < 1 )  initDefaultConstructors();

        if (!is.markSupported() && useCons.size() > 1) 
            is = new BufferedInputStream(is, maxSize);
        is.mark(maxSize);

        for (Constructor<? extends Credential> c : useCons ) {
            try {
                rv = c.newInstance(is, ids);
            }
            catch (InvocationTargetException ie ) {
                Throwable th = ie.getCause();

                if ( th != null && th instanceof ABACException ) 
                    err = (ABACException) th;
                else
                    err = new ABACException("Constructor error " + 
                                "(this is weird) " + ie.getMessage(), ie);
                rv = null;
            }
            catch (Exception e ) {
                err = new ABACException("Constructor error " + 
                        e.getMessage(), e);
                rv = null;
            }
            if ( rv != null ) 
                break;

            try {
                if (useCons.size() > 1) is.reset(); 
            }
            catch (IOException ie) { 
                break;
            }
        }

        if ( rv != null ) 
            return new Credential[] { rv };
        else 
            throw (err != null) ? err :
                new ABACException("null exception and failed construction??");
    }


    static Credential[] newInstance(File f, Set<Identity> ids) 
        throws ABACException {
        try {
            return newInstance(new FileInputStream(f), ids);
        }
        catch (FileNotFoundException e) {
            throw new CertInvalidException(e.getMessage(), e);
        }
    }
    static Credential[] newInstance(String fn, Set<Identity> ids) 
        throws ABACException {
        return newInstance(new File(fn), ids);
    }

    static public void registerClass(String name)
        throws ClassNotFoundException, NoSuchMethodException, 
                          SecurityException {

        Class c = Class.forName(name);
        Constructor<?  extends Credential> con = c.getConstructor(
                Class.forName("java.io.InputStream"),
                Class.forName("java.util.Collection"));

        cons.add(con);
    }
}