package com.ljq.util;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Map工具类
*
* @author jqlin
*/
public class MapUtils {
/**
* 从map集合中获取属性值
*
* @param <E>
* @param map
* map集合
* @param key
* 键对
* @param defaultValue
* 默认值
* @return
* @author jiqinlin
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public final static <E> E get(Map map, Object key, E defaultValue) {
Object o = map.get(key);
if (o == null)
return defaultValue;
return (E) o;
}
/**
* Map集合对象转化成 JavaBean集合对象
*
* @param javaBean JavaBean实例对象
* @param mapList Map数据集对象
* @return
* @author jqlin
*/
@SuppressWarnings({ "rawtypes" })
public static <T> List<T> map2Java(T javaBean, List<Map> mapList) {
if(mapList == null || mapList.isEmpty()){
return null;
}
List<T> objectList = new ArrayList<T>();
T object = null;
for(Map map : mapList){
if(map != null){
object = map2Java(javaBean, map);
objectList.add(object);
}
}
return objectList;
}
/**
* Map对象转化成 JavaBean对象
*
* @param javaBean JavaBean实例对象
* @param map Map对象
* @return
* @author jqlin
*/
@SuppressWarnings({ "rawtypes","unchecked", "hiding" })
public static <T> T map2Java(T javaBean, Map map) {
try {
// 获取javaBean属性
BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());
// 创建 JavaBean 对象
Object obj = javaBean.getClass().newInstance();
PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
if (propertyDescriptors != null && propertyDescriptors.length > 0) {
String propertyName = null; // javaBean属性名
Object propertyValue = null; // javaBean属性值
for (PropertyDescriptor pd : propertyDescriptors) {
propertyName = pd.getName();
if (map.containsKey(propertyName)) {
propertyValue = map.get(propertyName);
pd.getWriteMethod().invoke(obj, new Object[] { propertyValue });
}
}
return (T) obj;
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* JavaBean对象转化成Map对象
*
* @param javaBean
* @return
* @author jqlin
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public static Map java2Map(Object javaBean) {
Map map = new HashMap();
try {
// 获取javaBean属性
BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());
PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
if (propertyDescriptors != null && propertyDescriptors.length > 0) {
String propertyName = null; // javaBean属性名
Object propertyValue = null; // javaBean属性值
for (PropertyDescriptor pd : propertyDescriptors) {
propertyName = pd.getName();
if (!propertyName.equals("class")) {
Method readMethod = pd.getReadMethod();
propertyValue = readMethod.invoke(javaBean, new Object[0]);
map.put(propertyName, propertyValue);
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return map;
}
}