java中对象和Map互相转换的几种方式

在Java中，可以使用反射机制将对象转换为Map，同时也可以将Map转换为对象。以下是几种常见的方法：

1. 使用Apache Commons BeanUtils库

import org.apache.commons.beanutils.BeanUtils;
 
// 将对象转换为Map
public Map<String, Object> objectToMap(Object obj) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
    Map<String, Object> map = new HashMap<>();
    BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
    PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
    for (PropertyDescriptor pd : propertyDescriptors) {
        String propertyName = pd.getName();
        if (!"class".equals(propertyName)) {
            Method readMethod = pd.getReadMethod();
            Object result = readMethod.invoke(obj);
            map.put(propertyName, result);
        }
    }
    return map;
}
 
// 将Map转换为对象
public Object mapToObject(Map<String, Object> map, Class<?> objClass) throws IllegalAccessException, InstantiationException, InvocationTargetException {
    Object obj = objClass.newInstance();
    BeanUtils.populate(obj, map);
    return obj;
}

2. 使用Java Reflection API

import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
 
// 将对象转换为Map
public Map<String, Object> objectToMap(Object obj) throws IllegalAccessException {
    Map<String, Object> map = new HashMap<>();
    Class<?> clazz = obj.getClass();
    for (Field field : clazz.getDeclaredFields()) {
        field.setAccessible(true);
        map.put(field.getName(), field.get(obj));
    }
    return map;
}
 
// 将Map转换为对象
public Object mapToObject(Map<String, Object> map, Class<?> objClass) throws IllegalAccessException, InstantiationException {
    Object obj = objClass.newInstance();
    for (Map.Entry<String, Object> entry : map.entrySet()) {
        Field field = objClass.getDeclaredField(entry.getKey());
        field.setAccessible(true);
        field.set(obj, entry.getValue());
    }
    return obj;
}

3. 使用Jackson库

import com.fasterxml.jackson.databind.ObjectMapper;
 
// 将对象转换为Map
public Map<String, Object> objectToMap(Object obj) throws IOException {
    ObjectMapper objectMap