Java反射机制如何解决数据传值为空的问题

@Override
    public Map<String, Object> setnodeParamItems(DispatchInfoItem dispatchInfoItem) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
        Map<String, Object> map = new HashMap<>();
        DispatchInfo dispatchInfo = new DispatchInfo();
        if (null != dispatchInfoItem) {
            BeanUtils.copyProperties(dispatchInfoItem, dispatchInfo);
        }
        Method[] methods = dispatchInfo.getClass().getDeclaredMethods();
        if (methods != null) {
            for (Method method : methods) {
                String methodName = method.getName();
                if (methodName.startsWith("get")) {
                    Column column = dispatchInfo.getClass().getDeclaredMethod(methodName).getAnnotation(Column.class);
                    Object value = method.invoke(dispatchInfo);
                    if (null != column && StringUtils.isNotBlank(StringHelper.getString(value))) {
                        map.put(column.name(), value);
                    }
                }
            }
        }
        return map;
    }

public void getMethods(DispatchInfo dispatchInfo, Map<String, Object> map) throws Exception {
        //获取方法上的注解值
        Method[] methods = dispatchInfo.getClass().getDeclaredMethods();
        if (methods != null) {
            for (Method method : methods) {
                String methodName = method.getName();
                if (methodName.startsWith("get")) {
                    Column column = dispatchInfo.getClass().getDeclaredMethod(methodName).getAnnotation(Column.class);
                    if (column != null) {
                        String setMethodName = methodName.replaceFirst("(get)", "set");
                        Method setMethod = dispatchInfo.getClass().getMethod(setMethodName, method.getReturnType());
                        ;
                        if (null != map.get(column.name())) {
                            setMethod.invoke(dispatchInfo, map.get(column.name()));
                        }
                    }
                }
            }
        }
    }

package org.zkdg.utils.spring.annotations.impl;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.sql.SQLException;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;
import org.zkdg.utils.entity.ajaxEntity;
import org.zkdg.utils.spring.annotations.NNull;
@Aspect
@Component

public class AjaxEntityHandler {
    // @Pointcut("@annotation(org.zkdg.utils.annotations.AfterHandler)")
    @Pointcut("@annotation(org.zkdg.utils.spring.annotations.NullValidate)")
    // @Pointcut("execution(* org.dcexam.*.service.*.*(..))")
    public void beforeCall() {
        // service方法调用之前，检测参数，仅限第一个参数， 不能为空值
    }
    
    @Pointcut("execution(* org.dcexam.*.service.*.*(..))")
    public void afterThrowEx() {
        System.out.println("************\n\n\n\n\n\n\n\n\n\n\n\n*******");
    }
    @Around(value = "beforeCall()")
    public AjaxEntity doBefore(ProceedingJoinPoint point) throws Throwable {
        // TODO Auto-generated method stub
        // 判断不能为空
        Object[] args = point.getArgs();
        if (args == null || args[0] == null) {
            return new AjaxEntity("warning", "未选择任何数据。。。");
        }
        // 获取代理对象类方法参数
        MethodSignature target = (MethodSignature) point.getSignature();
        Annotation[][] annotations = target.getMethod().getParameterAnnotations();
        int argsIndex = 0;
        StringBuilder sb = new StringBuilder();
        for (Annotation[] annotation : annotations) {
            NNull nn = (NNull) annotation[0];
            String[] descs = nn.desc();
            String[] fields = nn.field();
            if (fields.length > 0 && fields.length > 0 && descs.length == fields.length) {
                for (int i = 0; i < fields.length; i++) {
                    Field field = args[argsIndex].getClass().getDeclaredField(fields[i]);
                    // 允许访问
                    field.setAccessible(true);
                    Object object = field.get(args[argsIndex]);
                    if (object == null) {
                        sb.append(descs[i]).append("不能为空。。。<br>");
                    }
                    if (object instanceof String) {
                        String string = (String) object;
                        if (string.trim().length() == 0)
                            sb.append(descs[i]).append("不能为空。。。<br>");
                        else if (string.trim().equals("0"))
                            sb.append("未选择" + descs[i] + "。。。<br>");
                    } else if (object instanceof Number) {
                        Integer integer = (Integer) object;
                        if (integer == 0)
                            sb.append("未选择" + descs[i] + "。。。<br>");
                    }
                }
                if (sb.length() > 0)
                    return AjaxEntity.ERROR(sb.toString());
            }
            argsIndex++;
        }
        // 加上@Nullvalidate 注解，不允许出现空 值
        for (Object obj : args) {
            if (obj == null) {
                return AjaxEntity.WARNING("出现了不允许的空值");
            } else if (obj instanceof String) {
                if (((String) obj).length() == 0) {
                    return AjaxEntity.WARNING("出现了不允许的空值");
                }
            }
        }
        AjaxEntity ajax = (AjaxEntity) point.proceed(args);
        return ajax == null ? AjaxEntity.ERROR("操作失败") : ajax;
    }
    
    @AfterThrowing(value = "afterThrowEx()", throwing = "ex")
    public void doAfterThrowEx(JoinPoint joinPoint, Exception ex) {
        AjaxEntity ajax = new AjaxEntity();
        if (ex.getCause() instanceof SQLException) {
            // 数据库操作异常
            ajax = AjaxEntity.ERROR("操作数据库时出现异常");
        }
    }
}