|
1
22 package org.jboss.aop.util;
23
24 import javassist.CtClass;
25 import javassist.CtConstructor;
26 import javassist.CtMethod;
27 import javassist.NotFoundException;
28
29
30 import java.io.ByteArrayOutputStream  ;
31 import java.io.DataOutputStream ;
32 import java.io.IOException ;
33 import java.security.DigestOutputStream ;
34 import java.security.MessageDigest ;
35 import java.security.NoSuchAlgorithmException ;
36 import java.util.HashMap ;
37
38
48 public class JavassistMethodHashing
49 {
50 public static long methodHash(CtMethod method)
51 {
52 try
53 {
54 CtClass[] parameterTypes = method.getParameterTypes();
55 String methodDesc = method.getName()+"(";
56 for(int j = 0; j < parameterTypes.length; j++)
57 {
58 methodDesc += getTypeString(parameterTypes[j]);
59 }
60 methodDesc += ")"+getTypeString(method.getReturnType());
61
62 long hash = 0;
63 ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream (512);
64 MessageDigest messagedigest = MessageDigest.getInstance("SHA");
65 DataOutputStream dataoutputstream = new DataOutputStream (new DigestOutputStream (bytearrayoutputstream, messagedigest));
66 dataoutputstream.writeUTF(methodDesc);
67 dataoutputstream.flush();
68 byte abyte0[] = messagedigest.digest();
69 for(int j = 0; j < Math.min(8, abyte0.length); j++)
70 hash += (long)(abyte0[j] & 0xff) << j * 8;
71 return hash;
72 }
73 catch (Exception e)
74 {
75 throw new RuntimeException (e);
76 }
77 }
78
79 public static long constructorHash(CtConstructor method)
80 {
81 try
82 {
83 CtClass[] parameterTypes = method.getParameterTypes();
84 String methodDesc = method.getDeclaringClass().getName()+"(";
85 for(int j = 0; j < parameterTypes.length; j++)
86 {
87 methodDesc += getTypeString(parameterTypes[j]);
88 }
89 methodDesc += ")";
90
91 long hash = 0;
92 ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream (512);
93 MessageDigest messagedigest = MessageDigest.getInstance("SHA");
94 DataOutputStream dataoutputstream = new DataOutputStream (new DigestOutputStream (bytearrayoutputstream, messagedigest));
95 dataoutputstream.writeUTF(methodDesc);
96 dataoutputstream.flush();
97 byte abyte0[] = messagedigest.digest();
98 for(int j = 0; j < Math.min(8, abyte0.length); j++)
99 hash += (long)(abyte0[j] & 0xff) << j * 8;
100 return hash;
101 }
102 catch (Exception e)
103 {
104 throw new RuntimeException (e);
105 }
106 }
107
108 static String getTypeString(CtClass cl)
109 throws Exception
110 {
111 if (cl.equals(CtClass.byteType))
112 {
113 return "B";
114 } else if (cl.equals(CtClass.charType))
115 {
116 return "C";
117 } else if (cl.equals(CtClass.doubleType))
118 {
119 return "D";
120 } else if (cl.equals(CtClass.floatType))
121 {
122 return "F";
123 } else if (cl.equals(CtClass.intType))
124 {
125 return "I";
126 } else if (cl.equals(CtClass.longType))
127 {
128 return "J";
129 } else if (cl.equals(CtClass.shortType))
130 {
131 return "S";
132 } else if (cl.equals(CtClass.booleanType))
133 {
134 return "Z";
135 } else if (cl.equals(CtClass.voidType))
136 {
137 return "V";
138 } else if (cl.isArray())
139 {
140 return "["+getTypeString(cl.getComponentType());
141 } else
142 {
143 return "L"+cl.getName().replace('.','/')+";";
144 }
145 }
146
147 private static void addDeclaredMethods(HashMap advised, CtClass superclass) throws Exception
148 {
149 CtMethod[] declaredMethods = superclass.getDeclaredMethods();
150 for (int i = 0; i < declaredMethods.length; i++)
151 {
152 if (superclass.isInterface() || Advisable.isAdvisable(declaredMethods[i]))
153 {
154 long hash = methodHash(declaredMethods[i]);
155 advised.put(new Long (hash), declaredMethods[i]);
156 }
157 }
158 }
159 private static void populateMethodTables(HashMap advised, CtClass superclass)
160 throws Exception
161 {
162 if (superclass == null) return;
163 if (superclass.getName().equals("java.lang.Object")) return;
164
165 populateMethodTables(advised, superclass.getSuperclass());
166 addDeclaredMethods(advised, superclass);
167 }
168
169 public static HashMap getMethodMap(CtClass clazz) throws Exception
170 {
171 HashMap map = new HashMap ();
172 populateMethodTables(map, clazz);
173 return map;
174 }
175
176 public static HashMap getDeclaredMethodMap(CtClass clazz) throws Exception
177 {
178 HashMap map = new HashMap ();
179 addDeclaredMethods(map, clazz);
180 return map;
181 }
182
183 }
184 |
Popular Tags |
Java API By Example, From Geeks To Geeks.