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

/**

  *

  * @author 王海明

  * @createData 2017年7月13日 上午8:36:23

  * @说明 :出了一些空值。。。

  */

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

     }

     /**

      * service发生异常时调用

      */

     @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;

     }

     /**

      *

      * @param joinPoint

      *            连接点

      * @param ex

      *            异常

      * @return AjaxEntity 异常信息

      */

     @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" );

         }

     }

}