Implementation:Risingwavelabs Risingwave DynMethods

Knowledge Sources	RisingWave
Domains	Reflection, Iceberg, Utilities
Language	Java
Lines	522
Last Updated	2026-02-09 07:00 GMT

Overview

Utility class providing a builder pattern for dynamically locating and invoking Java methods by reflection, ported from the Apache Iceberg project (originally from parquet-common).

Description

DynMethods is a utility class (with a private constructor) that enables runtime method discovery and invocation through Java reflection. It is part of the Apache Iceberg common utilities included in the RisingWave Iceberg sink connector module. The class provides several nested types:

• UnboundMethod -- A wrapper around java.lang.reflect.Method that provides typed invocation via invoke(Object target, Object... args) and invokeChecked(Object target, Object... args) (which throws checked exceptions). Handles variable-argument methods by tracking argument length. Provides bind(Object receiver) to create a BoundMethod, asStatic() to create a StaticMethod, and isStatic() / isNoop() checks. Includes a singleton NOOP instance that performs no operation and returns null.

• BoundMethod -- Wraps an UnboundMethod bound to a specific receiver object. Provides invoke(Object... args) and invokeChecked(Object... args).

• StaticMethod -- Wraps an UnboundMethod for static method invocation (receiver is always null). Provides invoke(Object... args) and invokeChecked(Object... args).

• Builder -- Fluent builder that searches for methods across multiple candidate classes:
  • impl(String className, String methodName, Class<?>... argClasses) -- Looks up a public method by class name.
  • impl(String className, Class<?>... argClasses) -- Uses the builder's method name.
  • impl(Class<?> targetClass, String methodName, Class<?>... argClasses) -- Looks up a public method on a known class.
  • impl(Class<?> targetClass, Class<?>... argClasses) -- Uses the builder's method name.
  • hiddenImpl(...) -- Looks up private/protected methods, making them accessible via AccessController.doPrivileged.
  • ctorImpl(Class<?> targetClass, Class<?>... argClasses) -- Delegates to DynConstructors.Builder for constructor lookup.
  • ctorImpl(String className, Class<?>... argClasses) -- Constructor lookup by class name.
  • orNoop() -- Falls back to the NOOP method if no implementation is found.
  • build() / buildChecked() -- Returns the found UnboundMethod or throws.
  • build(Object receiver) / buildChecked(Object receiver) -- Returns a BoundMethod.
  • buildStatic() / buildStaticChecked() -- Returns a StaticMethod.

• MakeAccessible -- A PrivilegedAction that calls setAccessible(true) on hidden methods.

Usage

Used internally by the Iceberg sink connector for reflective method invocation required by Iceberg catalog operations, enabling dynamic method dispatch without compile-time coupling to specific Iceberg internal implementations.

Code Reference

Source Location

• Repository: risingwave
• File: java/connector-node/risingwave-sink-iceberg/src/main/java/org/apache/iceberg/common/DynMethods.java
• Lines: 1-522

Signature

public class DynMethods {

    private DynMethods() {}

    public static class UnboundMethod {
        public <R> R invokeChecked(Object target, Object... args) throws Exception;
        public <R> R invoke(Object target, Object... args);
        public BoundMethod bind(Object receiver);
        public boolean isStatic();
        public boolean isNoop();
        public StaticMethod asStatic();
    }

    public static class BoundMethod {
        public <R> R invokeChecked(Object... args) throws Exception;
        public <R> R invoke(Object... args);
    }

    public static class StaticMethod {
        public <R> R invokeChecked(Object... args) throws Exception;
        public <R> R invoke(Object... args);
    }

    public static Builder builder(String methodName);

    public static class Builder {
        public Builder(String methodName);
        public Builder loader(ClassLoader newLoader);
        public Builder orNoop();
        public Builder impl(String className, String methodName, Class<?>... argClasses);
        public Builder impl(String className, Class<?>... argClasses);
        public Builder impl(Class<?> targetClass, String methodName, Class<?>... argClasses);
        public Builder impl(Class<?> targetClass, Class<?>... argClasses);
        public Builder ctorImpl(Class<?> targetClass, Class<?>... argClasses);
        public Builder ctorImpl(String className, Class<?>... argClasses);
        public Builder hiddenImpl(String className, String methodName, Class<?>... argClasses);
        public Builder hiddenImpl(String className, Class<?>... argClasses);
        public Builder hiddenImpl(Class<?> targetClass, String methodName, Class<?>... argClasses);
        public Builder hiddenImpl(Class<?> targetClass, Class<?>... argClasses);
        public UnboundMethod build();
        public BoundMethod build(Object receiver);
        public UnboundMethod buildChecked() throws NoSuchMethodException;
        public BoundMethod buildChecked(Object receiver) throws NoSuchMethodException;
        public StaticMethod buildStatic();
        public StaticMethod buildStaticChecked() throws NoSuchMethodException;
    }
}

Import

import org.apache.iceberg.common.DynMethods;

I/O Contract

Inputs

Name	Type	Required	Description
methodName	String	Yes	Name of the method to locate (passed to builder constructor)
className	String	No	Fully qualified class name to search for the method (resolved via Class.forName)
targetClass	Class<?>	No	Class instance to search for the method
argClasses	Class<?>[]	Varies	Parameter types for method signature matching
receiver / target	Object	Varies	Object instance for method invocation (required for non-static methods)
args	Object[]	Varies	Arguments to pass to the invoked method

Outputs

Name	Type	Description
UnboundMethod	DynMethods.UnboundMethod	Reflective method invoker not bound to a specific receiver
BoundMethod	DynMethods.BoundMethod	Reflective method invoker bound to a specific receiver object
StaticMethod	DynMethods.StaticMethod	Reflective invoker for static methods
R (generic)	Object	Return value of the invoked method

Exceptions

Exception	Condition
NoSuchMethodException	No matching method found (from buildChecked methods)
RuntimeException	No matching method found (from build methods) or invocation error
Exception	Checked exceptions from the invoked method (from invokeChecked)
IllegalStateException	Attempting to bind a static method or call asStatic on a non-static method
IllegalArgumentException	Receiver class is incompatible with the method's declaring class

Usage Examples

Invoking a Hidden Method

// Find and invoke a private method "computeHash" on SomeClass
DynMethods.UnboundMethod method = DynMethods.builder("computeHash")
        .hiddenImpl(SomeClass.class, "computeHash", String.class)
        .build();

String result = method.invoke(someInstance, "inputData");

Static Method with Fallback to NOOP

// Try multiple candidate classes for a static "initialize" method
DynMethods.StaticMethod initMethod = DynMethods.builder("initialize")
        .impl("com.example.NewCatalog", "initialize", Configuration.class)
        .impl("com.example.LegacyCatalog", "initialize", Configuration.class)
        .orNoop()
        .buildStatic();

initMethod.invoke(config);  // No-op if neither class is found

Bound Method Invocation

DynMethods.BoundMethod getter = DynMethods.builder("getMetadata")
        .impl(CatalogTable.class, "getMetadata")
        .build(tableInstance);

TableMetadata metadata = getter.invoke();

Related Pages

Implements Principle

• Principle:Risingwavelabs_Risingwave_Iceberg_Sink_Integration

Requires Environment

• Environment:Risingwavelabs_Risingwave_Java_Connector_Environment