libjava/classpath/gnu/classpath/jdwp/util/Signature.java

   1 /* Signature.java -- utility class to compute class and method signatures
   2    Copyright (C) 2005 Free Software Foundation
   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 terms of your choice, provided that you also meet, for each linked
  32 independent module, the terms and conditions of the license of that
  33 module.  An independent module is a module which is not derived from
  34 or based on this library.  If you modify this library, you may extend
  35 this exception to your version of the library, but you are not
  36 obligated to do so.  If you do not wish to do so, delete this
  37 exception statement from your version. */
  38
  39
  40 package gnu.classpath.jdwp.util;
  41
  42 import java.lang.reflect.Field;
  43 import java.lang.reflect.Method;
  44
  45 /**
  46  * A class to compute class and method signatures.
  47  *
  48  * @author Tom Tromey  (tromey@redhat.com)
  49  * @author Keith Seitz  (keiths@redhat.com)
  50  */
  51 public class Signature
  52 {
  53   /**
  54    * Computes the class signature, i.e., java.lang.String.class
  55    * returns "Ljava/lang/String;".
  56    *
  57    * @param theClass  the class for which to compute the signature
  58    * @return          the class's type signature
  59    */
  60   public static String computeClassSignature (Class theClass)
  61   {
  62     StringBuffer sb = new StringBuffer ();
  63     _addToSignature (sb, theClass);
  64     return sb.toString ();
  65   }
  66
  67   /**
  68    * Computes the field signature which is just the class signature of the
  69    * field's type, ie a Field of type java.lang.String this will return
  70    * "Ljava/lang/String;".
  71    *
  72    * @param field  the field for which to compute the signature
  73    * @return       the field's type signature
  74    */
  75   public static String computeFieldSignature (Field field)
  76   {
  77     return computeClassSignature (field.getType());
  78   }
  79
  80   /**
  81    * Computes the method signature, i.e., java.lang.String.split (String, int)
  82    * returns "(Ljava/lang/String;I)[Ljava/lang/String;"
  83    *
  84    * @param method  the method for which to compute the signature
  85    * @return        the method's type signature
  86    */
  87   public static String computeMethodSignature (Method method)
  88   {
  89     return _computeSignature (method.getReturnType (),
  90                               method.getParameterTypes ());
  91   }
  92
  93   private static String _computeSignature (Class returnType,
  94                                            Class[] paramTypes)
  95   {
  96     StringBuffer sb = new StringBuffer ("(");
  97     if (paramTypes != null)
  98       {
  99         for (int i = 0; i < paramTypes.length; ++i)
 100           _addToSignature (sb, paramTypes[i]);
 101       }
 102     sb.append (")");
 103     _addToSignature (sb, returnType);
 104     return sb.toString();
 105   }
 106
 107   private static void _addToSignature (StringBuffer sb, Class k)
 108   {
 109     // For some reason there's no easy way to get the signature of a
 110     // class.
 111     if (k.isPrimitive ())
 112       {
 113         if (k == void.class)
 114           sb.append('V');
 115         else if (k == boolean.class)
 116           sb.append('Z');
 117         else if (k == byte.class)
 118           sb.append('B');
 119         else if (k == char.class)
 120           sb.append('C');
 121         else if (k == short.class)
 122           sb.append('S');
 123         else if (k == int.class)
 124           sb.append('I');
 125         else if (k == float.class)
 126           sb.append('F');
 127         else if (k == double.class)
 128           sb.append('D');
 129         else if (k == long.class)
 130           sb.append('J');
 131         return;
 132       }
 133
 134     String name = k.getName ();
 135     int len = name.length ();
 136     sb.ensureCapacity (len);
 137     if (! k.isArray ())
 138       sb.append('L');
 139     for (int i = 0; i < len; ++i)
 140       {
 141         char c = name.charAt (i);
 142         if (c == '.')
 143           c = '/';
 144         sb.append (c);
 145       }
 146     if (! k.isArray ())
 147       sb.append(';');
 148   }
 149 }