content: /*
   * Copyright (C) 2021 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package androidx.test.internal.platform.reflect;
  
  import androidx.annotation.NonNull;
  import androidx.annotation.RestrictTo;
  import androidx.annotation.RestrictTo.Scope;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  /**
   * Helper class for making more performant reflection method invocations.
   *
   * <p>Lazy initializes and caches Method object to attempt to reduce reflection overhead.
   *
   * @hide
   */
  @RestrictTo(Scope.LIBRARY_GROUP)
  public class ReflectiveMethod<T> {
    private final String className;
    private final String methodName;
    private final Class<?>[] paramTypes;
    private final Class<?> clazz;
  
    // lazy init
    private boolean initialized = false;
    private Method method;
  
    /**
     * Creates a ReflectiveMethod.
     *
     * @param className the fully qualified class name that defines the method
     * @param methodName the method name to call
     * @param paramTypes the list of types of the method parameters, in order.
     */
    public ReflectiveMethod(String className, String methodName, Class<?>... paramTypes) {
      this.className = className;
      this.clazz = null;
      this.paramTypes = paramTypes;
      this.methodName = methodName;
    }
  
    public ReflectiveMethod(Class<?> clazz, String methodName, Class<?>... paramTypes) {
      this.className = null;
      this.clazz = clazz;
      this.paramTypes = paramTypes;
      this.methodName = methodName;
    }
  
    /**
     * Invoke the instance method.
     *
     * <p>See {@link java.lang.reflect.Method#invoke(Object, Object...)}
     *
     * @param object the object the underlying method is invoked from
     * @param paramValues the arguments used for the method call
     * @return the return value of the method
     * @throws ReflectionException if call could not be completed
     */
    public T invoke(Object object, Object... paramValues) throws ReflectionException {
      try {
        initIfNecessary();
        return (T) method.invoke(object, paramValues);
      } catch (ClassNotFoundException e) {
        throw new ReflectionException(e);
      } catch (InvocationTargetException e) {
        throw new ReflectionException(e);
      } catch (NoSuchMethodException e) {
        throw new ReflectionException(e);
      } catch (IllegalAccessException e) {
        throw new ReflectionException(e);
      }
    }
  
    /**
     * Invoke th static method.
     *
     * <p>See {@link java.lang.reflect.Method#invoke(Object, Object...)}
     *
     * @param paramValues the arguments used for the method call
     * @return the return value of the method
     * @throws ReflectionException if call could not be completed
     */
    public T invokeStatic(Object... paramValues) throws ReflectionException {
      return invoke(null, paramValues);
    }
  
    private synchronized void initIfNecessary() throws ClassNotFoundException, NoSuchMethodException {
      if (initialized) {
        return;
      }
      method = getClazz().getDeclaredMethod(methodName, paramTypes);
      method.setAccessible(true);
      initialized = true;
    }
  
    @NonNull
    private Class<?> getClazz() throws ClassNotFoundException {
      if (clazz == null) {
        return Class.forName(className);
      } else {
        return clazz;
      }
    }
  }
  