1 /* RMIHashes.java -- 2 Copyright (c) 1996, 1997, 1998, 1999, 2004 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.java.rmi.server; 40 41 import gnu.java.lang.CPStringBuilder; 42 43 import gnu.java.lang.reflect.TypeSignature; 44 45 import java.io.ByteArrayOutputStream; 46 import java.io.DataOutputStream; 47 import java.lang.reflect.Method; 48 import java.security.MessageDigest; 49 50 public class RMIHashes 51 { 52 //There're other places using DigestOutputStream to generate hash in classpath, but I think the way I used 53 //here is more efficient, anyway, you can switch to DigestOutputStream by doing like "//or:" comments say. 54 55 //or:add this statement: private static final NullOutputStream nullOutputStream = new NullOutputStream (); getMethodHash(Method meth)56 public static long getMethodHash(Method meth) 57 { 58 //Object Serialization Spec 8.3 59 try 60 { 61 MessageDigest md = MessageDigest.getInstance ("SHA"); 62 //or:remove this statement: DigestOutputStream digest_out = new DigestOutputStream (nullOutputStream, md); 63 ByteArrayOutputStream digest_out = new ByteArrayOutputStream(); 64 DataOutputStream data_out = new DataOutputStream (digest_out); 65 66 CPStringBuilder sbuf = new CPStringBuilder(); 67 sbuf.append(meth.getName()); 68 sbuf.append('('); 69 Class params[] = meth.getParameterTypes(); 70 for(int i = 0; i < params.length; i++) 71 sbuf.append(TypeSignature.getEncodingOfClass(params[i])); 72 sbuf.append(')'); 73 Class rcls = meth.getReturnType(); 74 if(rcls != Void.TYPE) 75 sbuf.append(TypeSignature.getEncodingOfClass(rcls)); 76 else 77 sbuf.append('V'); 78 79 data_out.writeUTF (sbuf.toString()); 80 data_out.flush(); 81 data_out.close (); 82 83 md.update(digest_out.toByteArray()); //or:remove this statement 84 byte[] sha = md.digest (); 85 long result = 0; 86 int len = sha.length < 8 ? sha.length : 8; 87 for (int i=0; i < len; i++) 88 result += (long)(sha[i] & 0xFF) << (8 * i); 89 return result; 90 }catch(Exception _){ 91 return -1L; 92 } 93 } 94 95 public static long getInterfaceHash(Class clazz) 96 { 97 return clazz.hashCode (); 98 } 99 } 100