Class ConstructorUtil

java.lang.Object
cloud.opencode.base.core.reflect.ConstructorUtil
public final class ConstructorUtil extends Object
Constructor Utility Class - Constructor reflection operations 构造器工具类 - 构造器反射操作

Provides utilities for constructor discovery, filtering, and instance creation.

提供构造器发现、过滤和实例创建操作工具。

Features | 主要功能:

  • Get all/public/default constructors - 获取全部/公共/默认构造器
  • Get by parameter types or annotation - 按参数类型或注解获取
  • Get min/max args constructors - 获取最少/最多参数构造器
  • Instance creation with type-safe API - 类型安全的实例创建

Usage Examples | 使用示例:

// Get default constructor - 获取默认构造器
Optional<Constructor<User>> ctor = ConstructorUtil.getDefaultConstructor(User.class);

// Create instance - 创建实例
User user = ConstructorUtil.newInstance(User.class);

// Get constructor by param types - 按参数类型获取
Optional<Constructor<User>> ctor = ConstructorUtil.getConstructor(User.class, String.class);

Security | 安全性:

  • Thread-safe: Yes (stateless) - 线程安全: 是 (无状态)
  • Null-safe: Returns Optional - 空值安全: 返回 Optional

Performance | 性能特性:

  • Time complexity: O(n) where n = declared constructors - O(n), n为声明的构造器数
  • Space complexity: O(1) per invocation - 每次调用 O(1)
Since:
JDK 25, opencode-base-core V1.0.0
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Method Details

    • getAllConstructors

      public static <T> List<Constructor<T>> getAllConstructors(Class<T> clazz)
      Gets all constructors 获取所有构造器

    • getPublicConstructors

      public static <T> List<Constructor<T>> getPublicConstructors(Class<T> clazz)
      Gets public constructors 获取公共构造器

    • getDefaultConstructor

      public static <T> Optional<Constructor<T>> getDefaultConstructor(Class<T> clazz)
      Gets the default constructor (no-arg) 获取默认构造器（无参）

    • getConstructor

      public static <T> Optional<Constructor<T>> getConstructor(Class<T> clazz, Class<?>... paramTypes)
      Gets the constructor with specified parameter types 获取指定参数类型的构造器

    • getConstructorsWithAnnotation

      public static <T> List<Constructor<T>> getConstructorsWithAnnotation(Class<T> clazz, Class<? extends Annotation> annotation)
      Gets constructors with the specified annotation 获取带有指定注解的构造器

    • getMinArgsConstructor

      public static <T> Optional<Constructor<T>> getMinArgsConstructor(Class<T> clazz)
      Gets the constructor with the fewest parameters 获取参数数量最少的构造器

    • getMaxArgsConstructor

      public static <T> Optional<Constructor<T>> getMaxArgsConstructor(Class<T> clazz)
      Gets the constructor with the most parameters 获取参数数量最多的构造器

    • hasDefaultConstructor

      public static boolean hasDefaultConstructor(Class<?> clazz)
      Checks if a default constructor exists 检查是否有默认构造器

    • isPublic

      public static boolean isPublic(Constructor<?> constructor)
      Checks if the constructor is public 检查构造器是否为 public

    • isPrivate

      public static boolean isPrivate(Constructor<?> constructor)
      Checks if the constructor is private 检查构造器是否为 private

    • newInstance

      public static <T> T newInstance(Constructor<T> constructor, Object... args)
      Creates an instance 创建实例

    • newInstance

      public static <T> T newInstance(Class<T> clazz)
      Creates an instance using the default constructor 使用默认构造器创建实例

    • getParameterNames

      public static String[] getParameterNames(Constructor<?> constructor)
      Gets constructor parameter names (requires -parameters compile flag) 获取构造器参数名称（需要编译时 -parameters 参数）