protected void injectGetByIndex(
ClassWriter classWriter, String targetClassName, List<Field> fields) {
MethodVisitor methodVisitor =
classWriter.visitMethod(
ACC_PUBLIC,
"get",
"(Ljava/lang/Object;I)Ljava/lang/Object;",
null,
new String[] {getInternalName(ILLEGAL_ACCESS_EXCEPTION.getCanonicalName())});
Boxer boxer = new Boxer(methodVisitor);
methodVisitor.visitCode();
methodVisitor.visitVarInsn(ILOAD, 2);
int maxStack = 6;
Label[] labels = new Label[fields.size()];
Label errorLabel = new Label();
for (int i = 0; i < fields.size(); i++) {
labels[i] = new Label();
}
methodVisitor.visitTableSwitchInsn(0, labels.length - 1, errorLabel, labels);
if (!fields.isEmpty()) {
maxStack--;
for (int i = 0; i < fields.size(); i++) {
Field field = fields.get(i);
Class<?> type = field.getType();
String fieldDescriptor = Type.getDescriptor(type);
methodVisitor.visitLabel(labels[i]);
if (i == 0) methodVisitor.visitFrame(F_APPEND, 1, new Object[] {targetClassName}, 0, null);
else methodVisitor.visitFrame(F_SAME, 0, null, 0, null);
if (isPublic(field)) {
methodVisitor.visitVarInsn(ALOAD, 1);
methodVisitor.visitTypeInsn(CHECKCAST, targetClassName);
methodVisitor.visitFieldInsn(GETFIELD, targetClassName, field.getName(), fieldDescriptor);
boxer.box(Type.getType(type));
} else {
injectReflectiveGetter(methodVisitor);
}
methodVisitor.visitInsn(ARETURN);
}
methodVisitor.visitLabel(errorLabel);
methodVisitor.visitFrame(F_SAME, 0, null, 0, null);
}
injectException(methodVisitor, IllegalAccessException.class);
methodVisitor.visitMaxs(maxStack, 3);
methodVisitor.visitEnd();
}
protected void injectException(
MethodVisitor methodVisitor, Class<? extends Throwable> throwable) {
methodVisitor.visitTypeInsn(NEW, getInternalName(throwable.getCanonicalName()));
methodVisitor.visitInsn(DUP);
methodVisitor.visitTypeInsn(NEW, "java/lang/StringBuilder");
methodVisitor.visitInsn(DUP);
methodVisitor.visitLdcInsn("Invalid index: ");
methodVisitor.visitMethodInsn(
INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V");
methodVisitor.visitVarInsn(ILOAD, 2);
methodVisitor.visitMethodInsn(
INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;");
methodVisitor.visitMethodInsn(
INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
methodVisitor.visitMethodInsn(
INVOKESPECIAL,
getInternalName(throwable.getCanonicalName()),
"<init>",
"(Ljava/lang/String;)V");
methodVisitor.visitInsn(ATHROW);
}
protected static String toSafeName(Class<?> clazz) {
return clazz.getCanonicalName().replace("[]", "Array").replace(".", "_");
}
