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1
21
22 package org.armedbear.lisp;
23
24 import java.lang.reflect.InvocationHandler  ;
25 import java.lang.reflect.Method ;
26 import java.lang.reflect.Proxy ;
27 import java.util.HashMap ;
28 import java.util.Map ;
29 import java.util.WeakHashMap ;
30
31 public final class JProxy extends Lisp
32 {
33 private static final Map table = new WeakHashMap ();
34
35 private static final Primitive _JNEW_PROXY =
38 new Primitive("%jnew-proxy", PACKAGE_JAVA, false, "interface &rest method-names-and-defs")
39 {
40 public LispObject execute(LispObject[] args) throws ConditionThrowable
41 {
42 int length = args.length;
43 if (length < 3 || length % 2 != 1)
44 return signal(new WrongNumberOfArgumentsException(this));
45 Map lispDefinedMethods = new HashMap ();
46 for (int i = 1; i < length; i = i+2)
47 lispDefinedMethods.put(args[i].getStringValue(),(Function)args[i+1]);
48 Class iface = (Class ) args[0].javaInstance();
49 Object proxy =
50 Proxy.newProxyInstance(iface.getClassLoader(), new Class [] { iface }, new LispHandler(table));
51 table.put(proxy, new Entry(iface, lispDefinedMethods));
52 return new JavaObject(proxy);
53 }
54 };
55
56 private static class LispHandler implements InvocationHandler
57 {
58 Map table;
59
60 LispHandler (Map table)
61 {
62 this.table = table;
63 }
64
65 public Object invoke(Object proxy, Method method, Object [] args)
66 {
67 String methodName = method.getName();
68
69 if (methodName.equals("hashCode")) {
70 return new Integer (System.identityHashCode(proxy));
71 } else if (methodName.equals("equals")) {
72 return (proxy == args[0] ? Boolean.TRUE : Boolean.FALSE);
73 } else if (methodName.equals("toString")) {
74 return proxy.getClass().getName() + '@' + Integer.toHexString(proxy.hashCode());
75 }
76
77 if (table.containsKey(proxy)) {
78 Entry entry = (Entry)table.get(proxy);
79 Function f = entry.getLispMethod(methodName);
80 if (f != null) {
81 if (args == null) args = new Object [0];
83 LispObject[] lispArgs = new LispObject[args.length];
84 for (int i = 0 ; i< args.length; i++)
85 lispArgs[i] = new JavaObject(args[i]);
86 try {
87 LispObject result = f.execute(lispArgs);
88 return (method.getReturnType() == void.class ? null : result.javaInstance());
89 }
90 catch (ConditionThrowable t) {
91 t.printStackTrace();
92 }
93 }
94 }
95 return null;
96 }
97 }
98
99 private static class Entry
100 {
101 Class iface;
102 Map lispDefinedMethods;
103
104 public Entry (Class iface, Map lispDefinedMethods)
105 {
106 this.iface = iface;
107 this.lispDefinedMethods = lispDefinedMethods;
108 }
109
110 public Function getLispMethod(String methodName)
111 {
112 if (lispDefinedMethods.containsKey(methodName))
113 return (Function)lispDefinedMethods.get(methodName);
114 return null;
115 }
116 }
117 }
118 |
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