org.snaker.engine.helper.ClassHelper Maven / Gradle / Ivy
/* Copyright 2013-2014 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 org.snaker.engine.helper;
import java.math.BigDecimal;
import java.math.BigInteger;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 类操作帮助类
* @author yuqs
* @version 1.0
*/
public class ClassHelper {
private static final Logger log = LoggerFactory.getLogger(ClassHelper.class);
/**
* 查询结果总记录数的类型转换
* @param count
* @return
*/
public static long castLong(Object count) {
if(count == null) return -1L;
if(count instanceof Long) {
return (Long)count;
} else if(count instanceof BigDecimal) {
return ((BigDecimal)count).longValue();
} else if(count instanceof Integer) {
return ((Integer)count).longValue();
} else if(count instanceof BigInteger) {
return ((BigInteger)count).longValue();
} else if(count instanceof Byte) {
return ((Byte)count).longValue();
} else if(count instanceof Short) {
return ((Short)count).longValue();
} else {
return -1L;
}
}
/**
* 根据指定的类名称加载类
* @param className
* @return
* @throws ClassNotFoundException
*/
public static Class loadClass(String className) throws ClassNotFoundException {
try {
return Thread.currentThread().getContextClassLoader().loadClass(className);
} catch (ClassNotFoundException e) {
try {
return Class.forName(className);
} catch (ClassNotFoundException ex) {
try {
return ClassLoader.class.getClassLoader().loadClass(className);
} catch (ClassNotFoundException exc) {
throw exc;
}
}
}
}
/**
* 实例化指定的类名称（全路径）
* @param clazzStr
* @return
* @throws Exception
*/
public static Object newInstance(String clazzStr) {
try {
log.debug("loading class:" + clazzStr);
Class clazz = loadClass(clazzStr);
return instantiate(clazz);
} catch (ClassNotFoundException e) {
log.error("Class not found.", e);
} catch (Exception ex) {
log.error("类型实例化失败[class=" + clazzStr + "]\n" + ex.getMessage());
}
return null;
}
/**
* 根据类的class实例化对象
* @param clazz
* @return
*/
public static T instantiate(Class clazz) {
if (clazz.isInterface()) {
log.error("所传递的class类型参数为接口，无法实例化");
return null;
}
try {
return clazz.newInstance();
} catch (Exception ex) {
log.error("检查传递的class类型参数是否为抽象类?", ex.getCause());
}
return null;
}
}