java.lang.Object

cloud.opencode.base.reflect.FieldUtil

public final class FieldUtil extends Object

Field Utility Class 字段工具类

Provides low-level field operation utilities with caching.

提供带缓存的底层字段操作工具。

Features | 主要功能:

Field discovery with caching - 带缓存的字段发现
Inherited field resolution - 继承字段解析
Field filtering by type, modifier, annotation - 按类型、修饰符、注解过滤字段

Usage Examples | 使用示例:

List<Field> fields = FieldUtil.getAllFields(User.class);
Field field = FieldUtil.getField(User.class, "name");

Security | 安全性:

Thread-safe: Yes (uses ConcurrentHashMap for caching) - 线程安全: 是（使用ConcurrentHashMap缓存）
Null-safe: No (caller must ensure non-null arguments) - 空值安全: 否（调用方须确保非空参数）

Performance | 性能特性:

Time complexity: O(1) for cached lookups; O(f) for first access where f is the number of fields (including inherited) - 时间复杂度: 缓存命中时 O(1)；首次访问为 O(f)，f为字段数量（含继承）
Space complexity: O(f) for the cached fields per class - 空间复杂度: O(f)，每类缓存字段

Since:

JDK 25, opencode-base-reflect V1.0.0

Author:

Leon Soo www.LeonSoo.com

See Also:

Method Summary

Modifier and Type

Method

Description

static void

clearCache()

Clears field cache 清除字段缓存

static void

clearCache(Class<?> clazz)

Clears cache for specific class 清除特定类的缓存

static List<Field>

getAllFields(Class<?> clazz)

Gets all fields including inherited (cached) 获取所有字段包含继承（缓存）

static Field[]

getDeclaredFields(Class<?> clazz)

Gets all declared fields (no inheritance) 获取所有声明的字段（不含继承）

static Field

getField(Class<?> clazz, String fieldName)

Gets field by name (cached) 按名称获取字段（缓存）

static Field

getFieldOrThrow(Class<?> clazz, String fieldName)

Gets field or throws exception 获取字段或抛出异常

static List<Field>

getFields(Class<?> clazz, Predicate<Field> predicate)

Gets fields matching predicate 获取匹配条件的字段

static List<Field>

getFieldsOfType(Class<?> clazz, Class<?> fieldType)

Gets fields of specific type 获取特定类型的字段

static List<Field>

getFieldsWithAnnotation(Class<?> clazz, Class<? extends Annotation> annotationClass)

Gets fields with annotation 获取带注解的字段

static Object

getFieldValue(Object object, String fieldName)

Gets field value by name, with unified Record/Class support.

static Type

getGenericType(Field field)

Gets field generic type 获取字段泛型类型

static List<Field>

getInstanceFields(Class<?> clazz)

Gets non-static fields 获取非静态字段

static List<Field>

getStaticFields(Class<?> clazz)

Gets static fields 获取静态字段

static Object

getStaticValue(Field field)

Gets static field value 获取静态字段值

static Class<?>

getType(Field field)

Gets field type 获取字段类型

static Object

getValue(Field field, Object target)

Gets field value 获取字段值

static <T> T

getValue(Field field, Object target, Class<T> type)

Gets field value with type cast 获取字段值并转型

static boolean

isFinal(Field field)

Checks if field is final 检查字段是否为final

static boolean

isStatic(Field field)

Checks if field is static 检查字段是否为静态

static boolean

isTransient(Field field)

Checks if field is transient 检查字段是否为transient

static boolean

isVolatile(Field field)

Checks if field is volatile 检查字段是否为volatile

static void

setStaticValue(Field field, Object value)

Sets static field value 设置静态字段值

static void

setValue(Field field, Object target, Object value)

Sets field value 设置字段值

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- getDeclaredFields
  
  public static Field[] getDeclaredFields(Class<?> clazz)
  
  Gets all declared fields (no inheritance) 获取所有声明的字段（不含继承）
  
  Parameters:
  
  clazz - the class | 类
  
  Returns:
  
  array of fields | 字段数组
- getAllFields
  
  public static List<Field> getAllFields(Class<?> clazz)
  
  Gets all fields including inherited (cached) 获取所有字段包含继承（缓存）
  
  Parameters:
  
  clazz - the class | 类
  
  Returns:
  
  list of fields | 字段列表
- getField
  
  public static Field getField(Class<?> clazz, String fieldName)
  
  Gets field by name (cached) 按名称获取字段（缓存）
  
  Parameters:
  
  clazz - the class | 类
  
  fieldName - the field name | 字段名
  
  Returns:
  
  the field or null | 字段或null
- getFieldOrThrow
  
  public static Field getFieldOrThrow(Class<?> clazz, String fieldName)
  
  Gets field or throws exception 获取字段或抛出异常
  
  Parameters:
  
  clazz - the class | 类
  
  fieldName - the field name | 字段名
  
  Returns:
  
  the field | 字段
  
  Throws:
  
  OpenReflectException - if not found | 如果未找到
- getFields
  
  public static List<Field> getFields(Class<?> clazz, Predicate<Field> predicate)
  
  Gets fields matching predicate 获取匹配条件的字段
  
  Parameters:
  
  clazz - the class | 类
  
  predicate - the predicate | 谓词
  
  Returns:
  
  list of matching fields | 匹配的字段列表
- getFieldsWithAnnotation
  
  public static List<Field> getFieldsWithAnnotation(Class<?> clazz, Class<? extends Annotation> annotationClass)
  
  Gets fields with annotation 获取带注解的字段
  
  Parameters:
  
  clazz - the class | 类
  
  annotationClass - the annotation class | 注解类
  
  Returns:
  
  list of fields | 字段列表
- getFieldsOfType
  
  public static List<Field> getFieldsOfType(Class<?> clazz, Class<?> fieldType)
  
  Gets fields of specific type 获取特定类型的字段
  
  Parameters:
  
  clazz - the class | 类
  
  fieldType - the field type | 字段类型
  
  Returns:
  
  list of fields | 字段列表
- getInstanceFields
  
  public static List<Field> getInstanceFields(Class<?> clazz)
  
  Gets non-static fields 获取非静态字段
  
  Parameters:
  
  clazz - the class | 类
  
  Returns:
  
  list of fields | 字段列表
- getStaticFields
  
  public static List<Field> getStaticFields(Class<?> clazz)
  
  Gets static fields 获取静态字段
  
  Parameters:
  
  clazz - the class | 类
  
  Returns:
  
  list of fields | 字段列表
- getFieldValue
  
  public static Object getFieldValue(Object object, String fieldName)
  
  Gets field value by name, with unified Record/Class support. 按名称获取字段值，统一支持 Record 和普通类。
  For records, invokes the accessor method. For classes, uses field reflection.
  
  对于 Record，调用访问器方法。对于普通类，使用字段反射。
  
  Parameters:
  
  object - the target object | 目标对象
  
  fieldName - the field name | 字段名
  
  Returns:
  
  the field value | 字段值
  
  Throws:
  
  OpenReflectException - if field not found or access failed | 如果字段未找到或访问失败
- getValue
  
  public static Object getValue(Field field, Object target)
  
  Gets field value 获取字段值
  
  Parameters:
  
  field - the field | 字段
  
  target - the target object | 目标对象
  
  Returns:
  
  the value | 值
- getValue
  
  public static <T> T getValue(Field field, Object target, Class<T> type)
  
  Gets field value with type cast 获取字段值并转型
  
  Type Parameters:
  
  T - the type | 类型
  
  Parameters:
  
  field - the field | 字段
  
  target - the target object | 目标对象
  
  type - the expected type | 期望类型
  
  Returns:
  
  the value | 值
- setValue
  
  public static void setValue(Field field, Object target, Object value)
  
  Sets field value 设置字段值
  
  Parameters:
  
  field - the field | 字段
  
  target - the target object | 目标对象
  
  value - the value | 值
- getStaticValue
  
  public static Object getStaticValue(Field field)
  
  Gets static field value 获取静态字段值
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  the value | 值
- setStaticValue
  
  public static void setStaticValue(Field field, Object value)
  
  Sets static field value 设置静态字段值
  
  Parameters:
  
  field - the field | 字段
  
  value - the value | 值
- getType
  
  public static Class<?> getType(Field field)
  
  Gets field type 获取字段类型
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  the type | 类型
- getGenericType
  
  public static Type getGenericType(Field field)
  
  Gets field generic type 获取字段泛型类型
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  the generic type | 泛型类型
- isStatic
  
  public static boolean isStatic(Field field)
  
  Checks if field is static 检查字段是否为静态
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  true if static | 如果是静态返回true
- isFinal
  
  public static boolean isFinal(Field field)
  
  Checks if field is final 检查字段是否为final
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  true if final | 如果是final返回true
- isTransient
  
  public static boolean isTransient(Field field)
  
  Checks if field is transient 检查字段是否为transient
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  true if transient | 如果是transient返回true
- isVolatile
  
  public static boolean isVolatile(Field field)
  
  Checks if field is volatile 检查字段是否为volatile
  
  Parameters:
  
  field - the field | 字段
  
  Returns:
  
  true if volatile | 如果是volatile返回true
- clearCache
  
  public static void clearCache()
  
  Clears field cache 清除字段缓存
- clearCache
  
  public static void clearCache(Class<?> clazz)
  
  Clears cache for specific class 清除特定类的缓存
  
  Parameters:
  
  clazz - the class | 类

Class FieldUtil

Method Summary

Methods inherited from class Object

Method Details

getDeclaredFields

getAllFields

getField

getFieldOrThrow

getFields

getFieldsWithAnnotation

getFieldsOfType

getInstanceFields

getStaticFields

getFieldValue

getValue

getValue

setValue

getStaticValue

setStaticValue

getType

getGenericType

isStatic

isFinal

isTransient

isVolatile

clearCache

clearCache