JCH
Java Community | Help. Code. Learn.•5d ago
asdru

optimize code for getting methodmodel of methods with @Select annotation

public static byte[] getClassBytes(Class<?> clazz) throws IOException {
    String classPath = clazz.getSimpleName() + ".class"; // Uses simple name for same package
    try (InputStream inputStream = clazz.getResourceAsStream(classPath)) {
        if (inputStream == null) {
            throw new IOException("Class file not found: " + classPath);
        }
        return inputStream.readAllBytes();
    }
}


public static List<Method> getMethodsAnnotatedWith(Class<?> clazz, Class<?> annotation) {
    List<Method> selectedMethods = new ArrayList<>();
    for (Method method : clazz.getDeclaredMethods()) {
        if (method.isAnnotationPresent(annotation.asSubclass(java.lang.annotation.Annotation.class))) {
            selectedMethods.add(method);
        }
    }
    return selectedMethods;
}

void main() throws IOException {
    byte[] bytes = getClassBytes(Test.class);
    ClassModel cm = ClassFile.of().parse(bytes);
    getMethodsAnnotatedWith(Test.class, Select.class).forEach(m -> cm.methods().forEach(mm -> {
        if (Objects.equals(mm.methodName().stringValue(), m.getName())) {
            mm.code().get().elementList().forEach(System.out::println);
        }
    }));
}
public static byte[] getClassBytes(Class<?> clazz) throws IOException {
    String classPath = clazz.getSimpleName() + ".class"; // Uses simple name for same package
    try (InputStream inputStream = clazz.getResourceAsStream(classPath)) {
        if (inputStream == null) {
            throw new IOException("Class file not found: " + classPath);
        }
        return inputStream.readAllBytes();
    }
}


public static List<Method> getMethodsAnnotatedWith(Class<?> clazz, Class<?> annotation) {
    List<Method> selectedMethods = new ArrayList<>();
    for (Method method : clazz.getDeclaredMethods()) {
        if (method.isAnnotationPresent(annotation.asSubclass(java.lang.annotation.Annotation.class))) {
            selectedMethods.add(method);
        }
    }
    return selectedMethods;
}

void main() throws IOException {
    byte[] bytes = getClassBytes(Test.class);
    ClassModel cm = ClassFile.of().parse(bytes);
    getMethodsAnnotatedWith(Test.class, Select.class).forEach(m -> cm.methods().forEach(mm -> {
        if (Objects.equals(mm.methodName().stringValue(), m.getName())) {
            mm.code().get().elementList().forEach(System.out::println);
        }
    }));
}
Im using java24's classfile api to get the string rapresentation of functions, and i want to select only the ones with the @Select annotation. my current implementation uses two loops, one to get the annotated methods and another to check if the name of the method matches with the method model. this O^2 implementation kinda sucks and i couldnt find in the classfile docs a better way to do this
java.lang.classfile (Java SE 24 & JDK 24 [build 35])
declaration: module: java.base, package: java.lang.classfile
1 Reply
JavaBot
JavaBot•5d ago
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