Package io.github.lukehutch.fastclasspathscanner.utils

Class ReflectionUtils

java.lang.Object

io.github.lukehutch.fastclasspathscanner.utils.ReflectionUtils

public class ReflectionUtils
extends Object

Reflection utility methods that can be used by ClassLoaderHandlers.

Field Summary

Fields

Modifier and Type	Field	Description
static String	JAVA_VERSION
static boolean	JAVA_VERSION_IS_8
static boolean	JAVA_VERSION_IS_9_PLUS

Constructor Summary

Constructors

Constructor	Description
ReflectionUtils()

Method Summary

Modifier and Type	Method	Description
static Class<?>	classForNameOrNull(String className)	Call Class.forName(className), but return null if any exception is thrown.
static Object	getFieldVal(Object obj, String fieldName, boolean throwException)	Get the value of the named field in the class of the given object or any of its superclasses.
static Object	getStaticFieldVal(Class<?> cls, String fieldName, boolean throwException)	Get the value of the named static field in the given class or any of its superclasses.
static Object	invokeDefaultMethod(Class<?> cls, String methodName, Class<?> returnType, ClassLoader classLoader, boolean throwException)	Invoke the named default interface method.
static Object	invokeMethod(Object obj, String methodName, boolean throwException)	Invoke the named method in the given object or its superclasses.
static Object	invokeMethod(Object obj, String methodName, Class<?> argType, Object arg, boolean throwException)	Invoke the named method in the given object or its superclasses.
static Object	invokeStaticMethod(Class<?> cls, String methodName, boolean throwException)	Invoke the named static method.
static Object	invokeStaticMethod(Class<?> cls, String methodName, Class<?> argType, Object arg, boolean throwException)	Invoke the named static method.

Methods inherited from class java.lang.Object

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

Field Detail

JAVA_VERSION

public static final String JAVA_VERSION

JAVA_VERSION_IS_8

public static final boolean JAVA_VERSION_IS_8

JAVA_VERSION_IS_9_PLUS

public static final boolean JAVA_VERSION_IS_9_PLUS

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

getFieldVal

public static Object getFieldVal(Object obj,
                                 String fieldName,
                                 boolean throwException)
                          throws IllegalArgumentException,
                                 NullPointerException

Get the value of the named field in the class of the given object or any of its superclasses. If an exception is thrown while trying to read the field, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null object, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

getStaticFieldVal

public static Object getStaticFieldVal(Class<?> cls,
                                       String fieldName,
                                       boolean throwException)
                                throws IllegalArgumentException,
                                       NullPointerException

Get the value of the named static field in the given class or any of its superclasses. If an exception is thrown while trying to read the field value, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null class reference, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

invokeMethod

public static Object invokeMethod(Object obj,
                                  String methodName,
                                  boolean throwException)
                           throws IllegalArgumentException,
                                  NullPointerException

Invoke the named method in the given object or its superclasses. If an exception is thrown while trying to call the method, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null object, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

invokeMethod

public static Object invokeMethod(Object obj,
                                  String methodName,
                                  Class<?> argType,
                                  Object arg,
                                  boolean throwException)
                           throws IllegalArgumentException,
                                  NullPointerException

Invoke the named method in the given object or its superclasses. If an exception is thrown while trying to call the method, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null object, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

invokeStaticMethod

public static Object invokeStaticMethod(Class<?> cls,
                                        String methodName,
                                        boolean throwException)
                                 throws IllegalArgumentException,
                                        NullPointerException

Invoke the named static method. If an exception is thrown while trying to call the method, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null class reference, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

invokeStaticMethod

public static Object invokeStaticMethod(Class<?> cls,
                                        String methodName,
                                        Class<?> argType,
                                        Object arg,
                                        boolean throwException)
                                 throws IllegalArgumentException,
                                        NullPointerException

Invoke the named static method. If an exception is thrown while trying to call the method, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null class reference, returns null unless throwException is true, then throws NullPointerException.

Throws:

IllegalArgumentException

NullPointerException

invokeDefaultMethod

public static Object invokeDefaultMethod(Class<?> cls,
                                         String methodName,
                                         Class<?> returnType,
                                         ClassLoader classLoader,
                                         boolean throwException)
                                  throws IllegalArgumentException,
                                         NullPointerException

Invoke the named default interface method. If an exception is thrown while trying to call the method, and throwException is true, then IllegalArgumentException is thrown wrapping the cause, otherwise this will return null. If passed a null class reference, returns null unless throwException is true, then throws NullPointerException. Uses the solution in https://stackoverflow.com/a/49532492/3950982 N.B. This is not completely tested...

Throws:

IllegalArgumentException

NullPointerException

classForNameOrNull

public static Class<?> classForNameOrNull(String className)

Call Class.forName(className), but return null if any exception is thrown.