|
1
16 package net.sf.cglib.reflect;
17
18 import java.lang.reflect.*;
19 import net.sf.cglib.core.*;
20 import org.objectweb.asm.ClassVisitor;
21 import org.objectweb.asm.Type;
22
23
27 abstract public class ConstructorDelegate {
28 private static final ConstructorKey KEY_FACTORY =
29 (ConstructorKey)KeyFactory.create(ConstructorKey.class, KeyFactory.CLASS_BY_NAME);
30
31 interface ConstructorKey {
32 public Object  newInstance(String declaring, String iface);
33 }
34
35 protected ConstructorDelegate() {
36 }
37
38 public static ConstructorDelegate create(Class targetClass, Class iface) {
39 Generator gen = new Generator();
40 gen.setTargetClass(targetClass);
41 gen.setInterface(iface);
42 return gen.create();
43 }
44
45 public static class Generator extends AbstractClassGenerator {
46 private static final Source SOURCE = new Source(ConstructorDelegate.class.getName());
47 private static final Type CONSTRUCTOR_DELEGATE =
48 TypeUtils.parseType("net.sf.cglib.reflect.ConstructorDelegate");
49
50 private Class iface;
51 private Class targetClass;
52
53 public Generator() {
54 super(SOURCE);
55 }
56
57 public void setInterface(Class iface) {
58 this.iface = iface;
59 }
60
61 public void setTargetClass(Class targetClass) {
62 this.targetClass = targetClass;
63 }
64
65 public ConstructorDelegate create() {
66 setNamePrefix(targetClass.getName());
67 Object key = KEY_FACTORY.newInstance(iface.getName(), targetClass.getName());
68 return (ConstructorDelegate)super.create(key);
69 }
70
71 protected ClassLoader getDefaultClassLoader() {
72 return targetClass.getClassLoader();
73 }
74
75 public void generateClass(ClassVisitor v) {
76 setNamePrefix(targetClass.getName());
77
78 final Method newInstance = ReflectUtils.findNewInstance(iface);
79 if (!newInstance.getReturnType().isAssignableFrom(targetClass)) {
80 throw new IllegalArgumentException ("incompatible return type");
81 }
82 final Constructor constructor;
83 try {
84 constructor = targetClass.getDeclaredConstructor(newInstance.getParameterTypes());
85 } catch (NoSuchMethodException e) {
86 throw new IllegalArgumentException ("interface does not match any known constructor");
87 }
88
89 ClassEmitter ce = new ClassEmitter(v);
90 ce.begin_class(Constants.V1_2,
91 Constants.ACC_PUBLIC,
92 getClassName(),
93 CONSTRUCTOR_DELEGATE,
94 new Type[]{ Type.getType(iface) },
95 Constants.SOURCE_FILE);
96 Type declaring = Type.getType(constructor.getDeclaringClass());
97 EmitUtils.null_constructor(ce);
98 CodeEmitter e = ce.begin_method(Constants.ACC_PUBLIC,
99 ReflectUtils.getSignature(newInstance),
100 ReflectUtils.getExceptionTypes(newInstance));
101 e.new_instance(declaring);
102 e.dup();
103 e.load_args();
104 e.invoke_constructor(declaring, ReflectUtils.getSignature(constructor));
105 e.return_value();
106 e.end_method();
107 ce.end_class();
108 }
109
110 protected Object firstInstance(Class type) {
111 return ReflectUtils.newInstance(type);
112 }
113
114 protected Object nextInstance(Object instance) {
115 return instance;
116 }
117 }
118 }
119 |
Popular Tags |
Java API By Example, From Geeks To Geeks.