版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/xiaobao5214/article/details/88425313
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class BeanUtil {
private static Logger logger = LoggerFactory.getLogger(BeanUtil.class);
/**
* bean对象转化成 Map<String, Object>
*
* @param t
* @param <T>
* @return
*/
public static <T> Map<String, Object> beanToMap(T t) {
if (t == null) {
return null;
}
Map<String, Object> map = new HashMap<String, Object>();
Field[] declaredFields = t.getClass().getDeclaredFields();
try {
for (Field field : declaredFields) {
field.setAccessible(true);
if ("serialVersionUID".equals(field.getName())) {
continue;
}
map.put(field.getName(), field.get(t));
}
} catch (IllegalAccessException e) {
logger.error("beanToMap error t:{} ", t, e);
}
return map;
}
/**
* 把一个对象转化为Map，如果这个对象中有日期类型，则把
* 这个日期类型转化为string类型
* @param t
* @param <T>
* @return
*/
public static <T> Map<String, Object> beanWithDateToMap(T t) {
DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
if (t == null) {
return null;
}
Map<String, Object> map = new HashMap<String, Object>();
Field[] declaredFields = t.getClass().getDeclaredFields();
Object fieldValue = null;
try {
for (Field field : declaredFields) {
field.setAccessible(true);
if ("serialVersionUID".equals(field.getName())) {
continue;
}
if (field.get(t) == null) {
fieldValue = "";
} else {
if ("java.util.Date".equals(field.getType().getName())) {
fieldValue = sdf.format((Date) field.get(t));
} else {
fieldValue = field.get(t);
}
}
map.put(field.getName(), fieldValue);
}
} catch (IllegalAccessException e) {
logger.error("beanToMap error t:{} ", t, e);
}
return map;
}
/**
* bean对象转化成 Map<String, String>
*
* @param t
* @param <T>
* @return
*/
public static <T> Map<String, String> beanToMapStr(T t) {
DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
if (t == null) {
return null;
}
Map<String, String> map = new HashMap<String, String>();
Field[] declaredFields = t.getClass().getDeclaredFields();
String fieldValue = null;
try {
for (Field field : declaredFields) {
field.setAccessible(true);
if ("serialVersionUID".equals(field.getName())) {
continue;
}
if (field.get(t) == null) {
fieldValue = "";
} else {
if ("java.util.Date".equals(field.getType().getName())) {
fieldValue = sdf.format((Date) field.get(t));
} else {
fieldValue = field.get(t).toString();
}
}
map.put(field.getName(), fieldValue);
}
} catch (IllegalAccessException e) {
logger.error("beanToMapStr error t:{} ", t, e);
}
return map;
}
/**
* bean对象集合转化成 List<Map<String, Object>>
*
* @param list
* @param <T>
* @return
*/
public static <T> List<Map<String, Object>> beanToMapList(List<T> list) {
List<Map<String, Object>> mapList = new ArrayList<>();
if (list != null && list.size() > 0){
for (T t : list) {
mapList.add(beanToMap(t));
}
}
return mapList;
}
/**
* bean对象集合转化成 List<Map<String, String>>
*
* @param list
* @param <T>
* @return
*/
public static <T> List<Map<String, String>> beanToMapStrList(List<T> list) {
List<Map<String, String>> mapList = new ArrayList<>();
if (list != null && list.size() > 0) {
for (T t : list) {
mapList.add(beanToMapStr(t));
}
}
return mapList;
}
/**
* 获取实体集合的某个字段的集合
* @param list 实体集合
* @param fieldName 字段名
* @param fieldClass 字段类型
* @param <T> 泛型实体类型
* @param <E> 泛型的字段类型
* @return
*/
public static <T,E> List<E> getFileldValueList(List<T> list,String fieldName,Class<E> fieldClass){
List<E> fieldList = new ArrayList<>();
try {
if (list != null && list.size() > 0) {
Field field = null;
for (T t : list) {
E value = null;
if (t instanceof Map){
Map map = (Map) t;
value = (E) map.get(fieldName);
} else {
field = t.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
value = (E) field.get(t);
}
fieldList.add(value);
}
}
} catch (Exception e) {
logger.error("getFileldList error list:{}, fieldName:{}, fieldClass:{}", list, fieldName, fieldClass, e);
}
return fieldList;
}
/**
* 获取实体集合以实体的某个字段为key，该实体为value的Map
* @param list 实体集合
* @param fieldName 字段名
* @param fieldClass 字段类型
* @param <T> 泛型实体类型
* @param <E> 泛型的字段类型
* @return
*/
public static <T, E> Map<E, T> getFileldBeanMap(List<T> list, String fieldName, Class<E> fieldClass) {
Map<E, T> resultMap = new HashMap<>();
try {
if (list != null && list.size() > 0){
Field field = null;
for (T t : list) {
field = t.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
E fieldValue = (E) field.get(t);
resultMap.put(fieldValue, t);
}
}
} catch (Exception e) {
logger.error("getFileldBeanMap error list:{}, fieldName:{}, fieldClass:{}", list, fieldName, fieldClass, e);
}
return resultMap;
}
/**
* 获取实体集合的某个字段的set集合 除去非空
* @param list 实体集合
* @param fieldName 字段名
* @param fieldClass 字段类型
* @param <T> 泛型实体类型
* @param <E> 泛型的字段类型
* @return
*/
public static <T,E> Set<E> getFileldValueSet(List<T> list,String fieldName,Class<E> fieldClass){
Set<E> fieldSet = new HashSet<>();
try {
if (list != null && list.size() > 0){
Field field = null;
for (T t : list) {
field = t.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
E value = (E) field.get(t);
if (value != null){
fieldSet.add(value);
}
}
}
} catch (Exception e) {
logger.error("getFileldList error list:{}, fieldName:{}, fieldClass:{}", list, fieldName, fieldClass, e);
}
return fieldSet;
}
public static <T,E extends Comparable> T getMatchValueInList(List<T> list,String fieldName,E matchKey){
try {
if (CheckObjUtil.isEmpty(list) || matchKey == null){
return null;
}
Field field = null;
for (T t : list) {
field = t.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
E value = (E) field.get(t);
if (value != null && value.compareTo(matchKey) == 0){
return t;
}
}
} catch (Exception e) {
logger.error("getMatchValueInList error list:{}, fieldName:{}, matchKey:{}", list, fieldName, matchKey, e);
}
return null;
}
/**
* 数字型的集合数据转换类型
* @param list 待转换的数字集合，(可以为String,Long,Integer,Short,Byte)
* @param targetClass 目标类型 (可以为String,Long,Integer,Short,Byte)
* @param <E>
* @param <T>
* @return
*/
public static <E,T> List<E> convertNumberList(List<T> list,Class<E> targetClass){
List<E> targetList = new ArrayList<>();
if (list != null && list.size() > 0){
for (T t : list){
E e = convertNumber(t,targetClass);
targetList.add(e);
}
}
return targetList;
}
/**
* 数字型的数据转换类型
* @param t 待转换的数字，(可以为String,Long,Integer,Short,Byte)
* @param targetClass 目标类型 (可以为String,Long,Integer,Short,Byte)
* @param <E>
* @param <T>
* @return
*/
public static <E, T> E convertNumber(T t, Class<E> targetClass) {
E e = null;
try{
if (t != null) {
Class<?> aClass = t.getClass();
System.out.println(aClass.getName());
String className = targetClass.getSimpleName();
String value = t.toString();
if (String.class.getSimpleName().equals(className)) {
e = (E) value;
} else if (Long.class.getSimpleName().equals(className)) {
e = (E) Long.valueOf(value);
} else if (Integer.class.getSimpleName().equals(className)) {
e = (E) Integer.valueOf(value);
} else if (Short.class.getSimpleName().equals(className)) {
e = (E) Short.valueOf(value);
} else if (Byte.class.getSimpleName().equals(className)) {
e = (E) Byte.valueOf(value);
}
}
}catch (Exception ex){
logger.error("convertNumber error t:{}, targetClass:{}", t, targetClass, ex);
}
return e;
}
}