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1
21
22 package org.apache.derby.impl.services.reflect;
23
24 import org.apache.derby.iapi.services.loader.GeneratedMethod;
25 import org.apache.derby.iapi.services.loader.GeneratedByteCode;
26 import org.apache.derby.iapi.services.loader.ClassFactory;
27
28 import org.apache.derby.iapi.error.StandardException;
29 import org.apache.derby.iapi.reference.SQLState;
30
31 import org.apache.derby.iapi.services.context.Context;
32
33 import java.lang.reflect.Method  ;
34 import java.util.Hashtable ;
35
36 public final class ReflectGeneratedClass extends LoadedGeneratedClass {
37
38 private final Hashtable methodCache;
39 private static final GeneratedMethod[] directs;
40
41
42 private final Class factoryClass;
43 private GCInstanceFactory factory;
44
45 static {
46 directs = new GeneratedMethod[10];
47 for (int i = 0; i < directs.length; i++) {
48 directs[i] = new DirectCall(i);
49 }
50 }
51
52 public ReflectGeneratedClass(ClassFactory cf, Class jvmClass, Class factoryClass) {
53 super(cf, jvmClass);
54 methodCache = new Hashtable ();
55 this.factoryClass = factoryClass;
56 }
57
58 public Object newInstance(Context context) throws StandardException {
59 if (factoryClass == null) {
60 return super.newInstance(context);
61 }
62
63 if (factory == null) {
64
65 Throwable t;
66 try {
67 factory = (GCInstanceFactory) factoryClass.newInstance();
68 t = null;
69 } catch (InstantiationException ie) {
70 t = ie;
71 } catch (IllegalAccessException iae) {
72 t = iae;
73 } catch (LinkageError le) {
74 t = le;
75 }
76
77 if (t != null)
78 throw StandardException.newException(SQLState.GENERATED_CLASS_INSTANCE_ERROR, t, getName());
79 }
80
81 GeneratedByteCode ni = factory.getNewInstance();
82 ni.initFromContext(context);
83 ni.setGC(this);
84 ni.postConstructor();
85 return ni;
86
87 }
88
89 public GeneratedMethod getMethod(String simpleName)
90 throws StandardException {
91
92 GeneratedMethod rm = (GeneratedMethod) methodCache.get(simpleName);
93 if (rm != null)
94 return rm;
95
96 try {
98 if ((simpleName.length() == 2) && simpleName.startsWith("e")) {
99
100 int id = ((int) simpleName.charAt(1)) - '0';
101
102 rm = directs[id];
103
104
105 }
106 else
107 {
108 Method m = getJVMClass().getMethod(simpleName, (Class []) null);
109
110 rm = new ReflectMethod(m);
111 }
112 methodCache.put(simpleName, rm);
113 return rm;
114
115 } catch (NoSuchMethodException nsme) {
116 throw StandardException.newException(SQLState.GENERATED_CLASS_NO_SUCH_METHOD,
117 nsme, getName(), simpleName);
118 }
119 }
120 }
121
122 class DirectCall implements GeneratedMethod {
123
124 private final int which;
125
126 DirectCall(int which) {
127
128 this.which = which;
129 }
130
131 public Object invoke(Object ref)
132 throws StandardException {
133
134 try {
135
136 GeneratedByteCode gref = (GeneratedByteCode) ref;
137 switch (which) {
138 case 0:
139 return gref.e0();
140 case 1:
141 return gref.e1();
142 case 2:
143 return gref.e2();
144 case 3:
145 return gref.e3();
146 case 4:
147 return gref.e4();
148 case 5:
149 return gref.e5();
150 case 6:
151 return gref.e6();
152 case 7:
153 return gref.e7();
154 case 8:
155 return gref.e8();
156 case 9:
157 return gref.e9();
158 }
159 return null;
160 } catch (StandardException se) {
161 throw se;
162 }
163 catch (Throwable t) {
164 throw StandardException.unexpectedUserException(t);
165 }
166 }
167 }
168 |
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