org.apache.hudi.common.util

Class ReflectionUtils

java.lang.Object

org.apache.hudi.common.util.ReflectionUtils

public class ReflectionUtils
extends Object

A utility class for reflection.

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
static Class<?>	getClass(String clazzName)
static Option<Method>	getMethod(Class<?> clazz, String methodName, Class<?>... parametersType) Gets a method based on the method name and type of parameters through reflection.
static Stream<String>	getTopLevelClassesInClasspath(Class<?> clazz) Scans all classes accessible from the context class loader which belong to the given package and subpackages.
static boolean	hasConstructor(String clazz, Class<?>[] constructorArgTypes) Check if the clazz has the target constructor or not, without throwing warn-level log.
static boolean	hasConstructor(String clazz, Class<?>[] constructorArgTypes, boolean silenceWarning) Check if the clazz has the target constructor or not.
static Object	invokeStaticMethod(String clazz, String methodName, Object[] args, Class<?>... parametersType) Invoke a static method of a class.
static boolean	isSubClass(String aClazzName, Class<?> superClazz) Checks if the given class with the name is a subclass of another class.
static <T> T	loadClass(String className)
static Object	loadClass(String clazz, Class<?>[] constructorArgTypes, Object... constructorArgs) Creates an instance of the given class.
static Object	loadClass(String clazz, Object... constructorArgs) Creates an instance of the given class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

getClass

public static Class<?> getClass(String clazzName)

loadClass

public static <T> T loadClass(String className)

loadClass

public static Object loadClass(String clazz,
                               Class<?>[] constructorArgTypes,
                               Object... constructorArgs)

Creates an instance of the given class. Use this version when dealing with interface types as constructor args.

hasConstructor

public static boolean hasConstructor(String clazz,
                                     Class<?>[] constructorArgTypes)

Check if the clazz has the target constructor or not, without throwing warn-level log.

Parameters:

clazz - Class name.

constructorArgTypes - Argument types of the constructor.

Returns:

hasConstructor

public static boolean hasConstructor(String clazz,
                                     Class<?>[] constructorArgTypes,
                                     boolean silenceWarning)

Check if the clazz has the target constructor or not.

When catch HoodieException from loadClass(java.lang.String), it's inconvenient to say if the exception was thrown due to the instantiation's own logic or missing constructor.

TODO: ReflectionUtils should throw a specific exception to indicate Reflection problem.

Parameters:

clazz - Class name.

constructorArgTypes - Argument types of the constructor.

silenceWarning - true to use debug-level logging; otherwise, use warn-level logging.

Returns:

true if the constructor exists; false otherwise.

loadClass

public static Object loadClass(String clazz,
                               Object... constructorArgs)

Creates an instance of the given class. Constructor arg types are inferred.

getTopLevelClassesInClasspath

public static Stream<String> getTopLevelClassesInClasspath(Class<?> clazz)

Scans all classes accessible from the context class loader which belong to the given package and subpackages.

Parameters:

clazz - class

Returns:

Stream of Class names in package

invokeStaticMethod

public static Object invokeStaticMethod(String clazz,
                                        String methodName,
                                        Object[] args,
                                        Class<?>... parametersType)

Invoke a static method of a class.

Parameters:

clazz -

methodName -

args -

parametersType -

Returns:

the return value of the method

getMethod

public static Option<Method> getMethod(Class<?> clazz,
                                       String methodName,
                                       Class<?>... parametersType)

Gets a method based on the method name and type of parameters through reflection.

Parameters:

clazz - Class object

methodName - method name

parametersType - type of parameters

Returns:

Option of the method if found; Option.empty() if not found or error out

isSubClass

public static boolean isSubClass(String aClazzName,
                                 Class<?> superClazz)

Checks if the given class with the name is a subclass of another class.

Parameters:

aClazzName - Class name.

superClazz - Super class to check.

Returns:

true if aClazzName is a subclass of superClazz; false otherwise.