Package nonapi.io.github.classgraph.reflection

Class ReflectionUtils

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

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Class<?> classForNameOrNull​(java.lang.String className)
      Call Class.forName(className), but return null if any exception is thrown.
      <T> T doPrivileged​(java.util.concurrent.Callable<T> callable)
      Call a method in the AccessController.doPrivileged(PrivilegedAction) context, using reflection, if possible (AccessController is deprecated in JDK 17).
      java.lang.Object getFieldVal​(boolean throwException, java.lang.Object obj, java.lang.reflect.Field field)
      Get the value of the field in the class of the given object or any of its superclasses.
      java.lang.Object getFieldVal​(boolean throwException, java.lang.Object obj, java.lang.String fieldName)
      Get the value of the named field in the class of the given object or any of its superclasses.
      java.lang.Object getStaticFieldVal​(boolean throwException, java.lang.Class<?> cls, java.lang.String fieldName)
      Get the value of the named field in the given class or any of its superclasses.
      java.lang.Object invokeMethod​(boolean throwException, java.lang.Object obj, java.lang.String methodName)
      Invoke the named method in the given object or its superclasses.
      java.lang.Object invokeMethod​(boolean throwException, java.lang.Object obj, java.lang.String methodName, java.lang.Class<?> argType, java.lang.Object param)
      Invoke the named method in the given object or its superclasses.
      java.lang.Object invokeStaticMethod​(boolean throwException, java.lang.Class<?> cls, java.lang.String methodName)
      Invoke the named method.
      java.lang.Object invokeStaticMethod​(boolean throwException, java.lang.Class<?> cls, java.lang.String methodName, java.lang.Class<?> argType, java.lang.Object param)
      Invoke the named method.
      java.lang.reflect.Method staticMethodForNameOrNull​(java.lang.String className, java.lang.String staticMethodName)
      Get a method by name, but return null if any exception is thrown.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • reflectionDriver

        public ReflectionDriver reflectionDriver
        The reflection driver to use.

      • accessControllerClass

        private java.lang.Class<?> accessControllerClass

      • privilegedActionClass

        private java.lang.Class<?> privilegedActionClass

      • accessControllerDoPrivileged

        private java.lang.reflect.Method accessControllerDoPrivileged

    • Method Detail

      • getFieldVal

        public java.lang.Object getFieldVal​(boolean throwException,
                                    java.lang.Object obj,
                                    java.lang.reflect.Field field)
                             throws java.lang.IllegalArgumentException
        Get the value of the 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:
        throwException - If true, throw an exception if the field value could not be read.
        obj - The object.
        field - The field.
        Returns:
        The field value.
        Throws:
        java.lang.IllegalArgumentException - If the field value could not be read.

      • getFieldVal

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

      • getStaticFieldVal

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

      • invokeMethod

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

      • invokeMethod

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

      • invokeStaticMethod

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

      • invokeStaticMethod

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

      • classForNameOrNull

        public java.lang.Class<?> classForNameOrNull​(java.lang.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.

      • staticMethodForNameOrNull

        public java.lang.reflect.Method staticMethodForNameOrNull​(java.lang.String className,
                                                          java.lang.String staticMethodName)
        Get a method by name, 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.

      • doPrivileged

        public <T> T doPrivileged​(java.util.concurrent.Callable<T> callable)
                   throws java.lang.Throwable
        Call a method in the AccessController.doPrivileged(PrivilegedAction) context, using reflection, if possible (AccessController is deprecated in JDK 17).
        Throws:
        java.lang.Throwable