Source for gnu.CORBA.CDR.IDLTypeHelper

   1: /* IDLTypeHelper.java --
   2:    Copyright (C) 2005 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.CORBA.CDR;
  40: 
  41: import gnu.CORBA.Minor;
  42: 
  43: import org.omg.CORBA.MARSHAL;
  44: import org.omg.CORBA.portable.BoxedValueHelper;
  45: import org.omg.CORBA.portable.InputStream;
  46: import org.omg.CORBA.portable.OutputStream;
  47: 
  48: import java.io.Serializable;
  49: import java.lang.reflect.Method;
  50: import java.lang.reflect.Modifier;
  51: 
  52: /**
  53:  * Handles case when the CORBA IDL type with the known helper is wrapped into
  54:  * Value type.
  55:  *
  56:  * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
  57:  */
  58: public class IDLTypeHelper
  59:   implements BoxedValueHelper
  60: {
  61:   /**
  62:    * A helper class.
  63:    */
  64:   protected Class helper;
  65: 
  66:   /**
  67:    * Argument values for Helper.id().
  68:    */
  69:   static final Object[] ARGS_ID_V = new Object[0];
  70: 
  71:   /**
  72:    * Argument types for Helper.id()).
  73:    */
  74:   static final Class[] ARGS_ID = new Class[0];
  75: 
  76:   /**
  77:    * Argument types for Helper.read.
  78:    */
  79:   static final Class[] ARGS_READ = new Class[] { org.omg.CORBA.portable.InputStream.class };
  80: 
  81:   /**
  82:    * Create an IDLTypeHelper that works via given helper class.
  83:    */
  84:   public IDLTypeHelper(Class a_helperClass)
  85:   {
  86:     helper = a_helperClass;
  87:   }
  88: 
  89:   /**
  90:    * Get the Id, returned by this helper (use reflection).
  91:    */
  92:   public String get_id()
  93:   {
  94:     try
  95:       {
  96:         Method m = helper.getMethod("id", ARGS_ID);
  97:         return (String) m.invoke(null, ARGS_ID_V);
  98:       }
  99:     catch (Exception ex)
 100:       {
 101:         MARSHAL m = new MARSHAL(msg() + " id()");
 102:         m.minor = Minor.Boxed;
 103:         m.initCause(ex);
 104:         throw m;
 105:       }
 106:   }
 107: 
 108:   /**
 109:    * Read an instance from the stream.
 110:    */
 111:   public Serializable read_value(InputStream input)
 112:   {
 113:     try
 114:       {
 115:         Method m = helper.getMethod("read", ARGS_READ);
 116:         return (Serializable) m.invoke(null, new Object[] { input });
 117:       }
 118:     catch (Exception ex)
 119:       {
 120:         MARSHAL m = new MARSHAL(msg() + " read(..)");
 121:         m.minor = Minor.Boxed;
 122:         m.initCause(ex);
 123:         throw m;
 124:       }
 125:   }
 126: 
 127:   /**
 128:    * Write the instance to the stream.
 129:    */
 130:   public void write_value(OutputStream output, Serializable value)
 131:   {
 132:     try
 133:       {
 134:         Method[] m = helper.getMethods();
 135: 
 136:         for (int i = 0; i < m.length; i++)
 137:           {
 138:             if (m[i].getName().equals("write")
 139:               && ((m[i].getModifiers() & Modifier.STATIC) != 0))
 140:               {
 141:                 Class[] p = m[i].getParameterTypes();
 142: 
 143:                 if (p.length == 2 && OutputStream.class.isAssignableFrom(p[0])
 144:                   && p[1].isAssignableFrom(value.getClass()))
 145:                   {
 146:                     m[i].invoke(null, new Object[] { output, value });
 147:                     return;
 148:                   }
 149:               }
 150:           }
 151:       }
 152:     catch (Exception ex)
 153:       {
 154:         MARSHAL m = new MARSHAL(msg() + " write(..)");
 155:         m.minor = Minor.Boxed;
 156:         m.initCause(ex);
 157:         throw m;
 158:       }
 159:   }
 160: 
 161:   /**
 162:    * Create the start of message for exceptions.
 163:    */
 164:   String msg()
 165:   {
 166:     return "Failed calling " + helper.getName() + " method: ";
 167:   }
 168: 
 169: }