public static FieldAccessor generate(
String fieldName, Class<?> cls, CodeLoader loader, boolean isStatic)
throws NoSuchFieldException, InstantiationException, IOException, IllegalAccessException {
String tempClassName = "_" + (loader.nextCount() & 0x7fffffff);
ClassFile cf =
new ClassFile(
tempClassName,
"dynamicinvoke.impl.FieldAccessor",
null,
(short) (Constants.ACC_PUBLIC | Constants.ACC_FINAL));
Field field = cls.getField(fieldName);
Class<?> type = field.getType();
String param = makeSignature(type);
cf.openMethod("<init>", "()V", Constants.ACC_PUBLIC);
cf.add(Opcode.ALOAD_0);
cf.add(Opcode.INVOKESPECIAL, "dynamicinvoke.impl.FieldAccessor", "<init>", "()", "V");
cf.add(Opcode.RETURN);
cf.closeMethod();
cf.openMethod("get", "(Ljava/lang/Object;)Ljava/lang/Object;", Constants.ACC_PUBLIC);
if (type.isPrimitive()) {
cf.add(Opcode.NEW, DynamicProxyFactory.wrapperClass(type));
cf.add(Opcode.DUP);
if (isStatic) {
cf.add(Opcode.GETSTATIC, cls.getName(), fieldName, param);
} else {
cf.add(Opcode.ALOAD_1);
if (!cls.equals(Object.class)) {
cf.add(Opcode.CHECKCAST, cls.getName());
}
cf.add(Opcode.GETFIELD, cls.getName(), fieldName, param);
}
cf.add(
Opcode.INVOKESPECIAL,
DynamicProxyFactory.wrapperClass(type),
"<init>",
"(" + ClassFile.signature(type) + ")",
"V");
} else {
if (isStatic) {
cf.add(Opcode.GETSTATIC, cls.getName(), fieldName, param);
} else {
cf.add(Opcode.ALOAD_1);
if (!cls.equals(Object.class)) {
cf.add(Opcode.CHECKCAST, cls.getName());
}
cf.add(Opcode.GETFIELD, cls.getName(), fieldName, param);
}
}
cf.add(Opcode.ARETURN);
cf.closeMethod();
cf.openMethod("set", "(Ljava/lang/Object;Ljava/lang/Object;)V", Constants.ACC_PUBLIC);
if (isStatic) {
cf.add(Opcode.ALOAD_1);
if (type.isPrimitive()) {
DynamicProxyFactory.castParam(cf, type);
} else {
cf.add(Opcode.CHECKCAST, type.getName());
}
cf.add(Opcode.PUTSTATIC, cls.getName(), fieldName, param);
} else {
cf.add(Opcode.ALOAD_1);
if (!cls.equals(Object.class)) {
cf.add(Opcode.CHECKCAST, cls.getName());
}
cf.add(Opcode.ALOAD_2);
if (type.isPrimitive()) {
DynamicProxyFactory.castParam(cf, type);
} else {
cf.add(Opcode.CHECKCAST, type.getName());
}
cf.add(Opcode.PUTFIELD, cls.getName(), fieldName, param);
}
cf.add(Opcode.RETURN);
cf.closeMethod();
ByteArrayOutputStream bout = new ByteArrayOutputStream();
DataOutputStream dout = new DataOutputStream(bout);
cf.write(dout);
/* debug(cf); */
Class<?> clazz = loader.define(tempClassName, bout.toByteArray(), 0, bout.size());
loader.resolve(clazz);
return (FieldAccessor) clazz.newInstance();
}
