public class TestClass {public static void main(String[] args) {	user user = new TestClass().new user();	user.setName(null);	user.setPassword(null);	System.out.println(user == null);}class user {	private String name;	private String password;	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public String getPassword() {		return password;	}	public void setPassword(String password) {		this.password = password;	}	}}

如果有需求需要判断对象内容为空，对象为空。可以写一个工具类

这个工具类还包括比较两个对象内属性，相同置为null,不同置为新对象的值。并返回比较后新生成的对象

import java.lang.reflect.Field;import java.util.HashMap;import java.util.Map;public class ClassUtils {	@SuppressWarnings("unchecked")	public static 
    
      T getDiffObject(T t1, T t2) {		Map
     
       map = getDiffField(t1, t2);		T result = null;		try {			if(map != null && map.size() > 0) {				Class
       clazz = Class.forName(t1.getClass().getName());				result = (T) clazz.newInstance();				for(Map.Entry
      
        me : map.entrySet()) {					Field field = clazz.getDeclaredField(me.getKey());					field.setAccessible(true);					field.set(result, me.getValue());				}			}		} catch (Exception e) {			e.printStackTrace();		}		return result;	}		public static 
       
         Map
        
          getDiffField(T t1, T t2) {		Map
         
           resultMap = new HashMap
          
           (); Class
            clazz1 = t1.getClass(); Class
            clazz2 = t2.getClass(); Field[] fields1 = clazz1.getDeclaredFields(); Field[] fields2 = clazz2.getDeclaredFields(); for(int i = 0; i < fields1.length; i++) { try { fields1[i].setAccessible(true); fields2[i].setAccessible(true); Object obj1 = fields1[i].get(t1); Object obj2 = fields2[i].get(t2); if((obj1 != null && !obj1.equals(obj2)) || (obj2 != null && !obj2.equals(obj1))) { resultMap.put(fields2[i].getName(), obj2); } } catch (IllegalArgumentException | IllegalAccessException e) { e.printStackTrace(); } } return resultMap; } public static boolean isNull(Object obj) { boolean result = true; if(obj != null) { Class
            clazz = obj.getClass(); Field[] fields = clazz.getDeclaredFields(); if(fields != null && fields.length > 0) { for(Field field : fields) { try { field.setAccessible(true); Object value = field.get(obj); if(value != null) { result = false; break; } } catch (IllegalArgumentException | IllegalAccessException e) { e.printStackTrace(); } } } } return result; }}