Package io.github.classgraph.utils

Class ReflectionUtils

  • public class ReflectionUtils
extends Object
    Reflection utility methods that can be used by ClassLoaderHandlers.

    • Constructor Detail

      • ReflectionUtils

        public ReflectionUtils()

    • Method Detail

      • getFieldVal

        public static Object getFieldVal​(Object obj,
                                 String fieldName,
                                 boolean throwException)
                          throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        obj - The object.
        fieldName - The field name.
        throwException - If true, throw an exception if the field value could not be read.
        Returns:
        The field value.
        Throws:
        IllegalArgumentException - If the field value could not be read.

      • getStaticFieldVal

        public static Object getStaticFieldVal​(Class<?> cls,
                                       String fieldName,
                                       boolean throwException)
                                throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        cls - The class.
        fieldName - The field name.
        throwException - If true, throw an exception if the field value could not be read.
        Returns:
        The field value.
        Throws:
        IllegalArgumentException - If the field value could not be read.

      • invokeMethod

        public static Object invokeMethod​(Object obj,
                                  String methodName,
                                  boolean throwException)
                           throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        obj - The object.
        methodName - The method name.
        throwException - If true, throw an exception if the field value could not be read.
        Returns:
        The field value.
        Throws:
        IllegalArgumentException - If the field value could not be read.

      • invokeMethod

        public static Object invokeMethod​(Object obj,
                                  String methodName,
                                  Class<?> argType,
                                  Object arg,
                                  boolean throwException)
                           throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        obj - The object.
        methodName - The method name.
        argType - The type of the parameter.
        arg - The argument value.
        throwException - Whether to throw an exception on failure.
        Returns:
        The result of the method invocation.
        Throws:
        IllegalArgumentException - If the method could not be invoked.

      • invokeStaticMethod

        public static Object invokeStaticMethod​(Class<?> cls,
                                        String methodName,
                                        boolean throwException)
                                 throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        cls - The class.
        methodName - The method name.
        throwException - Whether to throw an exception on failure.
        Returns:
        The result of the method invocation.
        Throws:
        IllegalArgumentException - If the method could not be invoked.

      • invokeStaticMethod

        public static Object invokeStaticMethod​(Class<?> cls,
                                        String methodName,
                                        Class<?> argType,
                                        Object arg,
                                        boolean throwException)
                                 throws IllegalArgumentException
        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 IllegalArgumentException.
        Parameters:
        cls - The class.
        methodName - The method name.
        argType - The type of the parameter.
        arg - The argument value.
        throwException - Whether to throw an exception on failure.
        Returns:
        The result of the method invocation.
        Throws:
        IllegalArgumentException - If the method could not be invoked.

      • invokeDefaultMethod

        public static Object invokeDefaultMethod​(Class<?> cls,
                                         String methodName,
                                         Class<?> returnType,
                                         ClassLoader classLoader,
                                         boolean throwException)
                                  throws IllegalArgumentException
        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 IllegalArgumentException. Uses the solution in https://stackoverflow.com/a/49532492/3950982 TODO: This is not tested...
        Parameters:
        cls - The object.
        methodName - The method name.
        returnType - The return type of the method.
        classLoader - The ClassLoader.
        throwException - Whether to throw an exception on failure.
        Returns:
        The result of the method invokation.
        Throws:
        IllegalArgumentException - If the method could not be invoked.

      • classForNameOrNull

        public static Class<?> classForNameOrNull​(String className)
        Call Class.forName(className), but return null if any exception is thrown.
        Parameters:
        className - The class name to load.
        Returns:
        The class of the requested name, or null if an exception was thrown while trying to load the class.