/**
* Copyright 2016 benjobs
* <p>
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* 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.opencron.server.dao;
import org.apache.commons.beanutils.ConvertUtils;
import org.opencron.common.utils.ExceptionHandler;
import org.hibernate.transform.BasicTransformerAdapter;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
@SuppressWarnings("unchecked")
public class BeanResultTransFormer<T> extends BasicTransformerAdapter implements Serializable {
private static final long serialVersionUID = 1483752531899989840L;
/**
* 已注册实例
*/
private final static Map<Class, BeanResultTransFormer> instanceRegistered = new ConcurrentHashMap<Class, BeanResultTransFormer>();
/**
* 属性名到setter方法映射
*/
private Map<String, List<Setter>> setters = new HashMap<String, List<Setter>>();
/**
* 实体类型
*/
private Class<T> beanClass;
/**
* 构造方法
*
* @param beanClass 实体类型
*/
protected BeanResultTransFormer(Class beanClass) {
this.register(this.beanClass = beanClass);
}
/**
* 注册实体类型
*
* @param beanClass
*/
protected void register(Class beanClass) {
Method[] methods = beanClass.getMethods();
//根据setter方法机获取属性名称
for (Method method : methods) {
if (filter(method)) {
String name = method.getName().toLowerCase().substring(3);
if (!setters.containsKey(name)) {
setters.put(name, new ArrayList<Setter>());
}
//同名的方法列表,不分大小写
setters.get(name).add(new Setter(method));
}
}
}
/**
* 选择Setter方法
*
* @param method
* @return
*/
boolean filter(Method method) {
if (method.getReturnType() == Void.TYPE && method.getParameterTypes().length == 1) {
String methodName = method.getName();
return methodName.startsWith("set") && methodName.length() > 3;
}
return false;
}
/**
* 或者指定类型的转换对象
*
* @param beanClass
* @return
*/
public static BeanResultTransFormer get(Class beanClass) {
synchronized (beanClass) {
if (!instanceRegistered.containsKey(beanClass)) {
instanceRegistered.put(beanClass, new BeanResultTransFormer(beanClass));
}
}
return instanceRegistered.get(beanClass);
}
/**
* 字段转换
* {@inheritDoc}
*/
public Object transformTuple(Object[] tuple, String[] aliases) {
try {
T data = beanClass.newInstance();
boolean isAllNull = true;
for (int i = 0; i < tuple.length; i++) {
String name = aliases[i];
Object value = tuple[i];
handle(data, name, value);
if (value != null && isAllNull) {
isAllNull = false;
}
}
if (isAllNull) {
return null;
}
return data;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public List transformList(List list) {
if (list.size() == 1) {
if (list.get(0) == null) {
list.remove(0);
}
}
return list;
}
/**
* 尽可能地调用最匹配的Setter方法进行赋值
*
* @param data
* @param name
* @param value
* @throws Exception
*/
protected void handle(T data, String name, Object value) throws Exception {
//忽略空值
if (value == null)
return;
List<Setter> setterList = setters.get(name.toLowerCase());
if (setterList == null || setterList.isEmpty())
return;
//唯一setter方法
if (setterList.size() == 1) {
Setter setter = setterList.get(0);
if (value != null && !setter.type.isInstance(value)) {
value = ConvertUtils.convert(value, setter.type);
}
setter.invoke(data, value);
return;
}
//参数兼容的方法列表
List<Setter> compatibleList = new ArrayList<Setter>();
//数字参数的方法列表
List<Setter> numericList = new ArrayList<Setter>();
for (Setter setter : setterList) {
Class<?> type = setter.type;
//参数类型一致
if (value != null && type == value.getClass()) {
setter.invoke(data, value);
}
//参数类型兼容
if (type.isInstance(value)) {
compatibleList.add(setter);
} else if (Number.class.isAssignableFrom(type)
&& value instanceof Number) {//数值型参数
numericList.add(setter);
}
}
if (compatibleList.size() == 1) {
compatibleList.get(0).invoke(data, value);
return;
}
if (compatibleList.isEmpty() && numericList.size() == 1) {
value = ConvertUtils.convert(value, numericList.get(0).type);
numericList.get(0).invoke(data, value);
return;
}
if (compatibleList.size() > 0 || numericList.size() > 0) {
throw new Exception("ambiguous setter methods to call");
}
}
class Setter {
Method method;
Class<?> type;
Setter(Method method) {
this.method = method;
this.type = wrapClass(method.getParameterTypes()[0]);
}
void invoke(Object object, Object arg) {
try {
if (type.isInstance(arg)) {
method.invoke(object, arg);
}
} catch (Exception e) {
ExceptionHandler.throwException(e);
}
}
Class<?> wrapClass(Class<?> clazz) {
if (clazz.equals(Boolean.TYPE)) {
return Boolean.class;
}
if (clazz.equals(Byte.TYPE)) {
return Byte.class;
}
if (clazz.equals(Short.TYPE)) {
return Short.class;
}
if (clazz.equals(Integer.TYPE)) {
return Integer.class;
}
if (clazz.equals(Long.TYPE)) {
return Long.class;
}
if (clazz.equals(Float.TYPE)) {
return Float.class;
}
if (clazz.equals(Double.TYPE)) {
return Double.class;
}
if (clazz.equals(Character.TYPE)) {
return Character.class;
}
return clazz;
}
}
}