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/*
* Copyright 2016 the original author or authors.
*
* 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 com.github.drinkjava2.jdialects;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import com.github.drinkjava2.jdialects.springsrc.utils.ReflectionUtils;
/**
* ClassCacheUtils is utility class to cache some info of classes read and write
* method
*
* @author Yong Zhu ([email protected])
* @since 1.0.0
*/
public abstract class ClassCacheUtils {// NOSONAR
// To check if a class exist, if exist, cache it to avoid check again
protected static ConcurrentHashMap> classExistCache = new ConcurrentHashMap>();
protected static Map, Map> uniqueMethodCache = new ConcurrentHashMap, Map>();
protected static Map, Map> classReadMethods = new ConcurrentHashMap, Map>();
protected static Map, Map> classWriteMethods = new ConcurrentHashMap, Map>();
/** * Check class if exist, if exit return it, otherwise return null */
public static Class checkClassExist(String className) {
Class result = classExistCache.get(className);
if (result != null) {
if (Object.class.equals(result))
return null;
else
return result;
}
try {
result = Class.forName(className);
if (result != null)
classExistCache.put(className, result);
else
classExistCache.put(className, Object.class);
return result;
} catch (Exception e) {
DialectException.eatException(e);
classExistCache.put(className, Object.class);
return null;
}
}
public static void registerClass(Class clazz) {
classExistCache.put(clazz.getName(), clazz);
}
/**
* Check if a unique method name exists in class, if exist return the method,
* otherwise return null
*/
public static Method checkMethodExist(Class clazz, String uniqueMethodName) {
if (clazz == null || StrUtils.isEmpty(uniqueMethodName))
return null;
Map methodMap = uniqueMethodCache.get(clazz);
if (methodMap != null && !methodMap.isEmpty()) {
Object result = methodMap.get(uniqueMethodName);
if (result != null) {
if (Object.class.equals(result))
return null;
else
return (Method) result;
}
}
if (methodMap == null) {
methodMap = new HashMap();
uniqueMethodCache.put(clazz, methodMap);
}
Method[] methods = clazz.getMethods();
for (Method method : methods)
if (uniqueMethodName != null && uniqueMethodName.equals(method.getName())) {
methodMap.put(uniqueMethodName, method);
return method;
}
methodMap.put(uniqueMethodName, Object.class);
return null;
}
private static LinkedHashMap sortMap(Map map) {
List> list = new ArrayList>(map.entrySet());
Collections.sort(list, new Comparator>() {
public int compare(Entry o1, Entry o2) {
return o1.getKey().compareTo(o2.getKey());
}
});
LinkedHashMap result = new LinkedHashMap();
for (Entry entry : list) {
result.put(entry.getKey(), entry.getValue());
}
return result;
}
public static synchronized void cacheReadWriteMethodsAndBoxField(Class clazz) {
BeanInfo beanInfo = null;
PropertyDescriptor[] pds = null;
try {
beanInfo = Introspector.getBeanInfo(clazz);
pds = beanInfo.getPropertyDescriptors();
} catch (Exception e) {
DialectException.throwEX("Class '" + clazz + "' can not get bean info", e);
}
Map readMethods = new HashMap();
Map writeMethods = new HashMap();
for (PropertyDescriptor pd : pds) {
String fieldName = pd.getName();
if ("class".equals(fieldName) || "simpleName".equals(fieldName) || "canonicalName".equals(fieldName)
|| "box".equals(fieldName))
continue;
Method readMtd = pd.getReadMethod();
readMethods.put(fieldName, readMtd);
Method writeMtd = pd.getWriteMethod();
if (writeMtd == null) {
writeMtd = ReflectionUtils.findMethod(clazz, "set" + StrUtils.toUpperCaseFirstOne(fieldName),
readMtd.getReturnType());
}
writeMethods.put(fieldName, writeMtd);
}
classReadMethods.put(clazz, sortMap(readMethods));
classWriteMethods.put(clazz, sortMap(writeMethods));
}
/** Return cached class read methods to avoid each time use reflect */
public static Map getClassReadMethods(Class clazz) {
Map readMethods = classReadMethods.get(clazz);
if (readMethods == null) {
cacheReadWriteMethodsAndBoxField(clazz);
return classReadMethods.get(clazz);
} else
return readMethods;
}
/** Return cached class field read method to avoid each time use reflect */
public static Method getClassFieldReadMethod(Class clazz, String fieldName) {
return getClassReadMethods(clazz).get(fieldName);
}
/** Return cached class write methods to avoid each time use reflect */
public static Map getClassWriteMethods(Class clazz) {
Map writeMethods = classWriteMethods.get(clazz);
if (writeMethods == null) {
cacheReadWriteMethodsAndBoxField(clazz);
return classWriteMethods.get(clazz);
} else
return writeMethods;
}
/** Return cached class field write method to avoid each time use reflect */
public static Method getClassFieldWriteMethod(Class clazz, String fieldName) {
return getClassWriteMethods(clazz).get(fieldName);
}
/** Read value from entityBean field */
public static Object readValueFromBeanField(Object entityBean, String fieldName) {
Method readMethod = ClassCacheUtils.getClassFieldReadMethod(entityBean.getClass(), fieldName);
if (readMethod == null) {
throw new DialectException(
"No mapping found for field '" + fieldName + "' in '" + entityBean.getClass() + "'");
} else
try {
return readMethod.invoke(entityBean);
} catch (Exception e) {
throw new DialectException(e);
}
}
/** write value to entityBean field */
public static void writeValueToBeanField(Object entityBean, String fieldName, Object value) {
Method writeMethod = ClassCacheUtils.getClassFieldWriteMethod(entityBean.getClass(), fieldName);
if (writeMethod == null) {
throw new DialectException("Can not find Java bean read method '" + fieldName + "'");
} else
try {
writeMethod.invoke(entityBean, value);
} catch (Exception e) {
throw new DialectException("FieldName '" + fieldName + "' can not write with value '" + value + "'", e);
}
}
/**
* Create a new Object by given entityClass, if any exception happen, throw
* {@link DialectException}
*/
public static Object createNewEntity(Class entityClass) {
try {
return entityClass.newInstance();
} catch (Exception e) {
throw new DialectException(e);
}
}
}