java中通过反射判断类中的属性是否为空

水深无声 2022-12-20 02:09 151阅读 0赞

public class ReflesStudyTest { 
    
        public static void main(String[] args) throws Exception { 
    
            ReflesStudy rs = new ReflesStudy();
            rs.setName("zhangsan");
            rs.setSex("nan");
    
            Class cs = rs.getClass();
            boolean isFlag = false;
            for(Field f : cs.getDeclaredFields()){ 
                f.setAccessible(true);//关闭java反射对象的安全检查
                System.out.println(f.getName()+":"+f.get(rs));
                if(null != f.get(rs)){ 
                    isFlag = true;
                }else{ 
                    isFlag = false;
                    break;
                }
            }
    
            if(isFlag){ 
                System.out.println("不为空");
            }else{ 
                System.out.println("为空");
            }
    
        }
    }

package reflex;
    
    public class ReflesStudy { 
    
        private String name;
        private Integer age;
        private String sex;
    
        public ReflesStudy() { 
        }
    
        public ReflesStudy(String name, Integer age, String sex) { 
            this.name = name;
            this.age = age;
            this.sex = sex;
        }
    
        public String getName() { 
            return name;
        }
    
        public Integer getAge() { 
            return age;
        }
    
        public String getSex() { 
            return sex;
        }
    
        public void setName(String name) { 
            this.name = name;
        }
    
        public void setAge(Integer age) { 
            this.age = age;
        }
    
        public void setSex(String sex) { 
            this.sex = sex;
        }
    
        @Override
        public String toString() { 
            return "reflesStudy{" +
                    "name='" + name + '\'' +
                    ", age='" + age + '\'' +
                    ", sex='" + sex + '\'' +
                    '}';
        }
    }

name:zhangsan
    age:null
    为空