java对象复制和属性值复制工具类[通俗易懂]

/**
* 实体类字段值相同的复制
*
* @author 隔壁老王 2017年8月18日
*/
public class CopyBeanUtil {
static Logger log = LoggerFactory.getLogger(CopyBeanUtil.class);
/**
* 复制sour里属性不为空的值到obje为空的属性
*
* @param obje    目标实体类
* @param sour    源实体类
* @param isCover 是否保留obje类里不为null的属性值(true为保留源值，属性为null则赋值)
* @return obje
*/
public static Object Copy(Object obje, Object sour, boolean isCover) {
Field[] fields = sour.getClass().getDeclaredFields();
for (int i = 0, j = fields.length; i < j; i++) {
String propertyName = fields[i].getName();
Object propertyValue = getProperty(sour, propertyName);
if (isCover) {
if (getProperty(obje, propertyName) == null && propertyValue != null) {
Object setProperty = setProperty(obje, propertyName, propertyValue);
}
} else {
Object setProperty = setProperty(obje, propertyName, propertyValue);
}
}
return obje;
}
/**
* 复制sour里属性不为空的值到obj里并相加
*
* @param obj     目标实体类
* @param sour    源实体类
* @param isCover
* @return obj
*/
public static Object CopyAndAdd(Object obj, Object sour, boolean isCover) {
Field[] fields = sour.getClass().getDeclaredFields();
for (int i = 0, j = fields.length; i < j; i++) {
String propertyName = fields[i].getName();
Object sourPropertyValue = getProperty(sour, propertyName);
Object objPropertyValue = getProperty(obj, propertyName);
if (isCover) {
if (objPropertyValue == null && sourPropertyValue != null) {
Object setProperty = setProperty(obj, propertyName, sourPropertyValue);
} else if (objPropertyValue != null && sourPropertyValue == null) {
Object setProperty = setProperty(obj, propertyName, objPropertyValue);
} else if (objPropertyValue != null && sourPropertyValue != null) {
Object setProperty = setProperty(obj, propertyName, ((int) sourPropertyValue) + (int) objPropertyValue);
}
}
}
return obj;
}
/**
* 得到值
*
* @param bean
* @param propertyName
* @return
*/
private static Object getProperty(Object bean, String propertyName) {
Class clazz = bean.getClass();
try {
Field field = clazz.getDeclaredField(propertyName);
Method method = clazz.getDeclaredMethod(getGetterName(field.getName(),field.getType()), new Class[]{});
return method.invoke(bean, new Object[]{});
} catch (Exception e) {
}
return null;
}
/**
* 给bean赋值
*
* @param bean
* @param propertyName
* @param value
* @return
*/
private static Object setProperty(Object bean, String propertyName, Object value) {
Class clazz = bean.getClass();
try {
Field field = clazz.getDeclaredField(propertyName);
Method method = clazz.getDeclaredMethod(getSetterName(field.getName()), new Class[]{field.getType()});
return method.invoke(bean, new Object[]{value});
} catch (Exception e) {
}
return null;
}
/**
* 根据变量名得到get方法
*
* @param propertyName
* @return
*/
private static String getGetterName(String propertyName) {
String method ;
if( propertyName.length()>1&& Character.isUpperCase(propertyName.charAt(1))){
method = "get" +propertyName;
}else{
method = "get" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
}
return method;
}
/**
* 根据变量名和类型获取getter方法
* @param propertyName
* @param type
* @return
*/
private static String getGetterName(String propertyName, Class<?> type) {
String method ;
if(type==Boolean.class|| type==boolean.class){
if("is".equalsIgnoreCase(propertyName.substring(0, 2))){
return propertyName;
}else{
return "is" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
}
}
if( propertyName.length()>1&& Character.isUpperCase(propertyName.charAt(1))){
method = "get" +propertyName;
}else{
method = "get" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
}
return method;
}
/**
* 得到setter方法
*
* @param propertyName 变量名
* @return
*/
private static String getSetterName(String propertyName) {
//        String method = "set" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
String method ;
if( propertyName.length()>1&& Character.isUpperCase(propertyName.charAt(1))){
method = "set" +propertyName;
}else{
method = "set" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
}
return method;
}
/**
* 父类集合转成子类集合集合通用方法(子类集合接收父类集合)
*
* @param list 父类集合
* @param <T>  子类
* @param <E>  父类
* @return
*/
public static <T, E> List<T> chang2ChildClassList(List<E> list) {
List<T> alist = new ArrayList<>();
for (E o : list) {
alist.add((T) o);
}
return alist;
}
/**
* 属性copy  复制sour里属性和obje里属性值忽略大小写相同的 ，不为空的值赋值到obje里
* 如果存在属性复杂类型并为有效值慎用或改进
*
* @param obje
* @param sour
* @param isCover 是否保留obje里面属性值不为空的字段值
* @return
*/
public static Object copyByIgnoreCase(Object obje, Object sour, boolean isCover) {
try {
Field[] objFields = obje.getClass().getDeclaredFields();
Field[] sourFields = sour.getClass().getDeclaredFields();
for (int i = 0; i < sourFields.length; i++) {
String sourPropertyName = sourFields[i].getName();
//获取来源对象的属性值
Object propertyValue = getSourPropertyValue(sour, sourPropertyName);
for (int j = 0; j < objFields.length; j++) {
try {
String objPropertyName = objFields[j].getName();
if (objPropertyName.equalsIgnoreCase(sourPropertyName)) {
if (isCover) {
if (getProperty(obje, objPropertyName) == null && propertyValue != null) {
setObjProperty(obje, objPropertyName, propertyValue);
}
} else {
setObjProperty(obje, objPropertyName, propertyValue);
}
break;
}
} catch (Exception e) {
log.error("给目标bean赋值出错,objPropertyName:{},value:{}",sourPropertyName,propertyValue,e);
e.printStackTrace();
}
}
}
} catch (SecurityException e) {
e.printStackTrace();
log.error("给目标bean赋值出错,obje:{},sour:{}", JSON.toJSONString(obje), JSON.toJSONString(sour),e);
}
return obje;
}
/**
* 根据属性名获取的值
*
* @param sourceBean
* @param sourcePropertyName
* @return
*/
private static Object getSourPropertyValue(Object sourceBean, String sourcePropertyName) {
Class clazz = sourceBean.getClass();
try {
Field field = clazz.getDeclaredField(sourcePropertyName);
Method method = clazz.getDeclaredMethod(getGetterName(field.getName(),field.getType()), new Class[]{});
return method.invoke(sourceBean, new Object[]{});
} catch (Exception e) {
log.error("获取属性名（不区分大小写）相似的值赋值出差", e);
}
return null;
}
/**
* 给目标bean赋值
*
* @param objBean
* @param sourcePropertyName
* @param value
* @return
*/
private static Object setObjPropertyBySourceProperty(Object objBean, String sourcePropertyName, Object value) {
Class clazz = objBean.getClass();
Field[] fields = clazz.getDeclaredFields();
try {
for (int i = 0, j = fields.length; i < j; i++) {
String propertyName = fields[i].getName();
if (sourcePropertyName.equalsIgnoreCase(propertyName)) {
Field field = clazz.getDeclaredField(propertyName);
if (field.getType() == BigDecimal.class) {
if (value instanceof String) {
value = new BigDecimal(String.valueOf(value));
} else if (value instanceof Integer || value instanceof Double) {
//							传double直接new BigDecimal，数会变大
value = BigDecimal.valueOf(Double.parseDouble(String.valueOf(value)));
}
}
if (field.getType() == Double.class || field.getType() == double.class) {
if (value instanceof BigDecimal) {
DecimalFormat df = new DecimalFormat("#.000000");
Double v = Double.parseDouble(String.valueOf(value));
value = df.format(v);
}
}
Method method = clazz.getDeclaredMethod(getSetterName(field.getName()), new Class[]{field.getType()});
return method.invoke(objBean, new Object[]{value});
}
}
} catch (Exception e) {
}
return null;
}
/**
* 给目标bean赋值
*
* @param objBean
* @param propertyName
* @param value
* @return
*/
private static Object setObjProperty(Object objBean, String propertyName, Object value) {
Class clazz = objBean.getClass();
try {
Field field = clazz.getDeclaredField(propertyName);
if (field.getType() == BigDecimal.class) {
if (value instanceof String) {
value = new BigDecimal(String.valueOf(value));
} else if (value instanceof Integer || value instanceof Double) {
//							传double直接new BigDecimal，数会变大
value = BigDecimal.valueOf(Double.parseDouble(String.valueOf(value)));
}
}
if (field.getType() == Double.class || field.getType() == double.class) {
if (value instanceof BigDecimal) {
DecimalFormat df = new DecimalFormat("#.000000");
Double v = Double.parseDouble(String.valueOf(value));
value =new BigDecimal(df.format(v));
}
}
if (field.getType() == Integer.class || field.getType() == int.class) {
if (value instanceof Float) {
value = Math.round(Float.parseFloat(String.valueOf(value)));
}
}
Method method = clazz.getDeclaredMethod(getSetterName(field.getName()), new Class[]{field.getType()});
log.info("给目标bean赋值,propertyName:{},value:{}",propertyName,value);
Object obj = method.invoke(objBean, new Object[]{value});
return obj;
} catch (Exception e) {
log.error("给目标bean赋值出错,propertyName:{},value:{}",propertyName,value,e);
}
return null;
}
public static void main(String[] args) {
//        ReAlarmResult re= new ReAlarmResult();
//        re.setAlarmContent("sdfsdfsd");
//        re.setBlat(2.234343);
//        re.setBlon(34.34324);
//        ReAlarmResult s = new ReAlarmResult();
//        s.setAlarmContent("222");
//        copyByIgnoreCase(s,re,true);
//        System.out.printf(JSON.toJSONString(s));
//        BeanUtils.copyProperties();
//BeanUtils.copyProperties();
}
}