InvokerCache.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.exception.UncheckedException;
import org.jfaster.mango.util.local.CacheLoader;
import org.jfaster.mango.util.local.DoubleCheckCache;
import org.jfaster.mango.util.local.LoadingCache;

import javax.annotation.Nullable;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.*;

/**
 * @author ash
 */
public class InvokerCache {

  @Nullable
  public static GetterInvoker getNullableGetterInvoker(Class<?> clazz, String propertyName) {
    return cache.get(clazz).getGetterInvoker(propertyName);
  }

  public static GetterInvoker getGetterInvoker(Class<?> clazz, String propertyName) {
    GetterInvoker invoker = getNullableGetterInvoker(clazz, propertyName);
    if (invoker == null) {
      throw new UnreachablePropertyException("There is no getter for property named '" + propertyName + "' in '" + clazz + "'");
    }
    return invoker;
  }

  public static List<GetterInvoker> getGetterInvokers(Class<?> clazz) {
    return cache.get(clazz).getGetterInvokers();
  }

  @Nullable
  public static SetterInvoker getNullableSetterInvoker(Class<?> clazz, String propertyName) {
    return cache.get(clazz).getSetterInvoker(propertyName);
  }

  public static SetterInvoker getSetterInvoker(Class<?> clazz, String propertyName) {
    SetterInvoker invoker = cache.get(clazz).getSetterInvoker(propertyName);
    if (invoker == null) {
      throw new UnreachablePropertyException("There is no setter for property named '" + propertyName + "' in '" + clazz + "'");
    }
    return invoker;
  }

  public static List<SetterInvoker> getSetterInvokers(Class<?> clazz) {
    return cache.get(clazz).getSetterInvokers();
  }

  private final static LoadingCache<Class<?>, BeanInfo> cache = new DoubleCheckCache<Class<?>, BeanInfo>(
      new CacheLoader<Class<?>, BeanInfo>() {
        public BeanInfo load(Class<?> clazz) {
          try {
            return new BeanInfo(clazz);
          } catch (Exception e) {
            throw new UncheckedException(e.getMessage(), e);
          }
        }
      });

  private static class BeanInfo {

    private final Map<String, GetterInvoker> getterInvokerMap;
    private final Map<String, SetterInvoker> setterInvokerMap;
    private final List<GetterInvoker> getterInvokers;
    private final List<SetterInvoker> setterInvokers;

    public BeanInfo(Class<?> clazz) throws Exception {
      Map<String, GetterInvoker> gim = new HashMap<String, GetterInvoker>();
      Map<String, SetterInvoker> sim = new HashMap<String, SetterInvoker>();
      List<GetterInvoker> gis = new ArrayList<GetterInvoker>();
      List<SetterInvoker> sis = new ArrayList<SetterInvoker>();

      java.beans.BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
      for (PropertyDescriptor pd : beanInfo.getPropertyDescriptors()) {
        if (!Class.class.equals(pd.getPropertyType())) {
          String name = pd.getName();
          String bname = isBoolean(pd.getPropertyType()) ?
              "is" + Character.toUpperCase(name.charAt(0)) + name.substring(1, name.length()) :
              null;
          Method readMethod = pd.getReadMethod();

          if (readMethod != null) {
            FunctionalGetterInvoker fgi = FunctionalGetterInvoker.create(name, readMethod);
            gim.put(name, fgi);
            gis.add(fgi);
            if (bname != null) { // 特殊处理boolean类型
              FunctionalGetterInvoker bfgi = FunctionalGetterInvoker.create(bname, readMethod);
              gim.put(bname, bfgi);
              gis.add(bfgi);
            }
          }
          Method writeMethod = pd.getWriteMethod();
          if (writeMethod != null) { // 特殊处理boolean类型
            FunctionalSetterInvoker fsi = FunctionalSetterInvoker.create(name, writeMethod);
            sim.put(name, fsi);
            sis.add(fsi);
            if (bname != null) {
              FunctionalSetterInvoker bfsi = FunctionalSetterInvoker.create(bname, writeMethod);
              sim.put(bname, bfsi);
              sis.add(bfsi);
            }
          }
        }
      }

      getterInvokerMap = Collections.unmodifiableMap(gim);
      setterInvokerMap = Collections.unmodifiableMap(sim);
      getterInvokers = Collections.unmodifiableList(gis);
      setterInvokers = Collections.unmodifiableList(sis);
    }

    GetterInvoker getGetterInvoker(String propertyName) {
      return getterInvokerMap.get(propertyName);
    }

    SetterInvoker getSetterInvoker(String propertyName) {
      return setterInvokerMap.get(propertyName);
    }

    private List<GetterInvoker> getGetterInvokers() {
      return getterInvokers;
    }

    private List<SetterInvoker> getSetterInvokers() {
      return setterInvokers;
    }

    private static boolean isBoolean(Class<?> clazz) {
      return boolean.class.equals(clazz) || Boolean.class.equals(clazz);
    }

  }

}