FunctionalSetterInvoker.java

/*
 * Copyright 2014 mango.jfaster.org
 *
 * The Mango Project licenses this file to you 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 org.jfaster.mango.invoker;

import org.jfaster.mango.annotation.Setter;
import org.jfaster.mango.exception.UncheckedException;
import org.jfaster.mango.util.reflect.Reflection;
import org.jfaster.mango.util.reflect.TokenTuple;
import org.jfaster.mango.util.reflect.TypeToken;
import org.jfaster.mango.util.reflect.Types;

import javax.annotation.Nullable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

/**
 * @author ash
 */
public class FunctionalSetterInvoker extends MethodNamedObject implements SetterInvoker {

  private FunctionAdapter functionAdapter;
  private Type parameterType;
  private Class<?> parameterRawType;

  private Type runtimeOutputType;
  private Class<?> runtimeOutputRawType;

  private FunctionalSetterInvoker(String name, Method method) {
    super(name, method);
    TypeToken<?> parameterToken = TypeToken.of(method.getGenericParameterTypes()[0]);
    runtimeOutputType = parameterToken.getType();
    runtimeOutputRawType = parameterToken.getRawType();

    Setter setterAnno = method.getAnnotation(Setter.class);

    if (setterAnno != null) { // 启用函数式调用功能
      Class<? extends DummySetterFunction<?, ?>> funcClass = setterAnno.value();
      if (SetterFunction.class.isAssignableFrom(funcClass)) {
        functionAdapter = new SetterFunctionAdapter((SetterFunction) Reflection.instantiateClass(funcClass));
      } else if (RuntimeSetterFunction.class.isAssignableFrom(funcClass)) {
        functionAdapter = new RuntimeSetterFunctionAdapter((RuntimeSetterFunction) Reflection.instantiateClass(funcClass));
      } else {
        throw new IllegalArgumentException("error func class '" + funcClass + "'");
      }

      TokenTuple tokenTuple = TypeToken.of(funcClass).resolveFatherClassTuple(DummySetterFunction.class);
      TypeToken<?> inputToken = tokenTuple.getFirst();
      TypeToken<?> outputToken = tokenTuple.getSecond();

      TypeToken<?> wrapParameterToken = parameterToken.wrap();
      if (functionAdapter instanceof RuntimeSetterFunctionAdapter) { // 针对继承RuntimeSetterFunction的
        if (!outputToken.isAssignableFrom(wrapParameterToken)) {
          throw new ClassCastException("function[" + functionAdapter.getFunction().getClass() + "] " +
              "on method[" + method + "] error, function's outputType[" + outputToken.getType() + "] " +
              "must be assignable from method's parameterType[" + parameterToken.getType() + "]");
        }
      } else { // 针对继承LiteSetterFunction的
        if (!wrapParameterToken.isAssignableFrom(outputToken)) {
          throw new ClassCastException("function[" + functionAdapter.getFunction().getClass() + "] " +
              "on method[" + method + "] error, method's parameterType[" + parameterToken.getType() + "] " +
              "must be assignable from function's outputType[" + outputToken.getType() + "]");
        }
      }
      parameterToken = inputToken;
    }
    parameterType = parameterToken.getType();
    parameterRawType = parameterToken.getRawType();
  }

  public static FunctionalSetterInvoker create(String name, Method method) {
    return new FunctionalSetterInvoker(name, method);
  }

  @Override
  public void invoke(Object object, @Nullable Object parameter) {
    try {
      if (functionAdapter != null) {
        parameter = functionAdapter.apply(parameter, runtimeOutputType);
      }
      if (parameter == null && runtimeOutputRawType.isPrimitive()) {
        throw new NullPointerException("property " + getName() + " of " +
            object.getClass() + " is primitive, can not be assigned to null");
      }
      if (parameter != null && !Types.isAssignable(runtimeOutputRawType, parameter.getClass())) {
        throw new ClassCastException("cannot convert value of type [" + parameter.getClass().getName() +
            "] to required type [" + runtimeOutputRawType.getName() + "] " +
            "for property '" + getName() + "' of " + object.getClass());
      }
      method.invoke(object, parameter);
    } catch (IllegalAccessException e) {
      throw new UncheckedException(e.getMessage(), e.getCause());
    } catch (InvocationTargetException e) {
      throw new UncheckedException(e.getMessage(), e.getCause());
    }
  }

  @Override
  public Type getParameterType() {
    return parameterType;
  }

  @Override
  public Class<?> getParameterRawType() {
    return parameterRawType;
  }

  interface FunctionAdapter {

    @Nullable
    public Object apply(@Nullable Object input, Type runtimeOutputType);

    public DummySetterFunction getFunction();

  }

  static class SetterFunctionAdapter implements FunctionAdapter {

    private final SetterFunction function;

    SetterFunctionAdapter(SetterFunction function) {
      this.function = function;
    }

    @SuppressWarnings("unchecked")
    @Nullable
    @Override
    public Object apply(@Nullable Object input, Type runtimeOutputType) {
      return function.apply(input);
    }

    @Override
    public DummySetterFunction getFunction() {
      return function;
    }

  }

  static class RuntimeSetterFunctionAdapter implements FunctionAdapter {

    private final RuntimeSetterFunction function;

    RuntimeSetterFunctionAdapter(RuntimeSetterFunction function) {
      this.function = function;
    }

    @SuppressWarnings("unchecked")
    @Nullable
    @Override
    public Object apply(@Nullable Object input, Type runtimeOutputType) {
      return function.apply(input, runtimeOutputType);
    }

    @Override
    public DummySetterFunction getFunction() {
      return function;
    }

  }

}