Java对象与字节工具类简单实现
以下代码主要实现功能：对象Object与字节数组相转换；根据源对象创建实例、复制对象值；把字符串转换为基本类型对象（String、Integer、Short、Double、Float）；利用反射实现对象之间属性复制 ； 对象属性值复制，仅复制指定名称的属性值 。
package com.xiu.util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeanUtils;
/**
*对象和字节工具类
*
* @author xiu
* @version 2017年8月9日 下午2:38:01
*/
public class ObjectUtil {
private static final Logger log = LoggerFactory.getLogger(ObjectUtil.class);
private ObjectUtil() {
}
/**
* 对象转换成字节数组
*
* @param obj
* 对象
* @return byte[]
*/
public static byte[] objectToByteArray(Object obj){
if (obj == null) {
return null;
}
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
(new ObjectOutputStream(bos)).writeObject(obj);
return bos.toByteArray();
} catch (IOException e) {
log.error("对象转换成字节数组出错 ", e);
return null;
}
}
/**
* 字节数组转换成对象
*
* @param buffer
* @return Object
*/
public static Object byteArrayToObject(byte[] buffer) {
if (buffer == null || buffer.length == 0) {
return null;
}
try {
ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
ObjectInputStream ois = new ObjectInputStream(bais);
return ois.readObject();
} catch (Exception e) {
log.error("字节数组转换成对象出错", e);
return null;
}
}
/**
* 根据源对象创建实例
*
* @param type
* @param value
* @return
*/
public static T createObject(Class type, V value) {
T typeInstance;
try {
typeInstance = type.newInstance();
BeanUtils.copyProperties(typeInstance, value);
} catch (Exception e) {
typeInstance = null;
}
return typeInstance;
}
/**
* 复制对象值
*
* @param dest
* 目标对象
* @param src
* 源对象
*/
@SuppressWarnings("unused")
private static void copyObjectValue(Object dest, Object src) {
BeanUtils.copyProperties(dest, src);
}
/**
* 把Number转换为基本类型对象
*
* @param str
* @param c
* @return
*/
@SuppressWarnings("unchecked")
public static T numberToBasicType(Number num, Class clazz) {
if (Integer.class == clazz || int.class == clazz) {
return (T) Integer.valueOf(num.intValue());
}else if (Long.class == clazz || long.class == clazz) {
return (T) Long.valueOf(num.longValue());
}else if (Double.class == clazz || double.class == clazz) {
return (T) Double.valueOf(num.doubleValue());
}else if (Float.class == clazz || float.class == clazz) {
return (T) Float.valueOf(num.floatValue());
}else if (Short.class == clazz || short.class == clazz) {
return (T) Short.valueOf(num.shortValue());
} else{
throw new IllegalArgumentException("无效的类型： " + clazz.getSimpleName());
}
}
/**
* 把字符串转换为基本类型对象（String、Integer、Short、Double、Float） 前提条件：字符串是数字
*
* @param str
* @param c
* @return
*/
@SuppressWarnings("unchecked")
public static T stringNumber2BasicTypes(String str, Class c) {
if (String.class.equals(c)) {
return (T) str;
} else if (Integer.class.equals(c)|| int.class == c) {
return (T) Integer.valueOf(str);
} else if (Long.class.equals(c)|| long.class == c) {
return (T) Long.valueOf(str);
} else if (Double.class.equals(c)|| double.class == c) {
return (T) Double.valueOf(str);
} else if (Float.class.equals(c)|| float.class == c) {
return (T) Float.valueOf(str);
} else if (Short.class.equals(c)|| short.class == c) {
return (T) Short.valueOf(str);
} else {
return null;
}
}
/**
* 利用反射实现对象之间属性复制
* @param from
* @param to
*/
public static void copyProperties(Object from, Object to) {
try {
copyPropertiesExclude(from, to, null);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 复制对象属性
* @param from
* @param to
* @param excludsArray 排除属性列表
* @throws Exception
*/
@SuppressWarnings("rawtypes")
private static void copyPropertiesExclude(Object from, Object to, String[] excludsArray) throws Exception {
List excludesList = null;
if (excludsArray != null && excludsArray.length > 0) {
excludesList = Arrays.asList(excludsArray);//构造列表对象
}
//getDeclaredMethods()方法返回一个数组，包括 public, protected, default (package) 访问和private方法的Method对象，但不包括继承的方法
Method[] fromMethods = from.getClass().getDeclaredMethods();
Method[] toMethods = to.getClass().getDeclaredMethods();
Method fromMethod = null, toMethod = null;
String fromMethodName = null, toMethodName = null;
for (int i = 0; i < fromMethods.length; i++) {//遍历源对象中的所有属性
fromMethod = fromMethods[i];
fromMethodName = fromMethod.getName();
if (!fromMethodName.contains("get")) {
continue;
}
//排除列表检测
if(excludesList != null && excludesList.contains(fromMethodName.substring(3).toLowerCase())) {
continue;
}
toMethodName = "set" + fromMethodName.substring(3);
toMethod = findMethodByName(toMethods, toMethodName);
if (toMethod == null)
continue;
Object value = fromMethod.invoke(from, new Object[0]);
if(value == null)
continue;
//集合类判空处理
if(value instanceof Collection) {
Collection newValue = (Collection)value;
if(newValue.size() <= 0)
continue;
}
toMethod.setAccessible(true);
toMethod.invoke(to, new Object[] {value});
}
}
/**
* 从方法数组中获取指定名称的方法
*
* @param methods
* @param name
* @return
*/
public static Method findMethodByName(Method[] methods, String name) {
for (int j = 0; j < methods.length; j++) {
if (methods[j].getName().equals(name))
return methods[j];
}
return null;
}
/**
* 对象属性值复制，仅复制指定名称的属性值
* @param from
* @param to
* @param includsArray 排除属性列表
* @throws Exception
*/
@SuppressWarnings("rawtypes")
public static void copyPropertiesInclude(Object from, Object to, String[] includsArray) throws Exception {
List includesList = null;
if(includsArray != null && includsArray.length > 0) {
includesList = Arrays.asList(includsArray); //构造列表对象
} else {
return;
}
Method[] fromMethods = from.getClass().getDeclaredMethods();
Method[] toMethods = to.getClass().getDeclaredMethods();
Method fromMethod = null, toMethod = null;
String fromMethodName = null, toMethodName = null;
for (int i = 0; i < fromMethods.length; i++) {
fromMethod = fromMethods[i];
fromMethodName = fromMethod.getName();
if (!fromMethodName.contains("get")) {
continue;
}
//排除列表检测
String str = fromMethodName.substring(3);
if(!includesList.contains(str.substring(0,1).toLowerCase() + str.substring(1))) {
continue;
}
toMethodName = "set" + fromMethodName.substring(3);
toMethod = findMethodByName(toMethods, toMethodName);
if (toMethod == null)
continue;
Object value = fromMethod.invoke(from, new Object[0]);
if(value == null)
continue;
//集合类判空处理
if(value instanceof Collection) {
Collection newValue = (Collection)value;
if(newValue.size() <= 0)
continue;
}
toMethod.invoke(to, new Object[] {value});
}
}
}