1 /*
   2  * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.reflect;
  27 
  28 /** Assists in iterating down a method's signature */
  29 
  30 public class SignatureIterator {
  31     private String sig;
  32     private int idx;
  33 
  34     public SignatureIterator(String sig) {
  35         this.sig = sig;
  36         reset();
  37     }
  38 
  39     public void reset() {
  40         idx = 1;
  41     }
  42 
  43     public boolean atEnd() {
  44         return sig.charAt(idx) == ')';
  45     }
  46 
  47     public String next() {
  48         if (atEnd()) return null;
  49         char c = sig.charAt(idx);
  50         if (c != '[' && c != 'L') {
  51             ++idx;
  52             return new String(new char[] { c });
  53         }
  54         // Walk forward to end of entry
  55         int endIdx = idx;
  56         if (c == '[') {
  57             while ((c = sig.charAt(endIdx)) == '[') {
  58                 endIdx++;
  59             }
  60         }
  61 
  62         if (c == 'L') {
  63             while (sig.charAt(endIdx) != ';') {
  64                 endIdx++;
  65             }
  66         }
  67 
  68         int beginIdx = idx;
  69         idx = endIdx + 1;
  70         return sig.substring(beginIdx, idx);
  71     }
  72 
  73     /** Should only be called when atEnd() is true. Does not change
  74         state of iterator. */
  75     public String returnType() {
  76         if (!atEnd()) {
  77             throw new InternalError("Illegal use of SignatureIterator");
  78         }
  79         return sig.substring(idx + 1, sig.length());
  80     }
  81 }