利用反射和自定义注解优化参数处理

文章目录

自定义注解
类定义
反射和注解取值格式化参数
测试

自定义注解

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface PropertyAnnotation {
    //字段类型: STRING->0,Number 1,Decimal 2,DateTime 3, Date 4 ,int 5,Float 6,Double 7
    int type() default 0;
    //时间格式
    String dateformat() default "yyyy-MM-dd";
    //最大长度默认50
    int maxlen() default 50;
    //是否强制截取
    boolean truncate() default false;
    //填充符号 固定长度不满足长度填充字符，金额字段一般是0,一般是左填充
    String fillpadding() default "*";
    //默认值
    String value() default "";

}

类定义

/**
 * 支付的参数
 */
public class PayParamInfo {
    //支付标题
    @PropertyAnnotation(type = 0,maxlen = 20,truncate  = true,value = "支付订单",fillpadding = "#")
    private String payTitle;
    //支付日期时间
    @PropertyAnnotation(type =3,maxlen = 14,dateformat = "yyyy-MM-dd hh24:mi:ss")
    private LocalDateTime payDateTime;
    //支付数量
    @PropertyAnnotation(type = 5,maxlen = 8,fillpadding = "0")
    private int payNum;
    //支付金额 分
    @PropertyAnnotation(type = 2,maxlen = 18,fillpadding = "0")
    private BigDecimal payAmount;
   ///省略set  get
}

反射和注解取值格式化参数

 /**
     * 格式化参数
     * @param payParamInfo
     * @return
     * @throws IllegalAccessException
     */
    public String FormatParams(PayParamInfo payParamInfo) throws IllegalAccessException {
        StringBuilder sb = new StringBuilder();
        for (Field field : payParamInfo.getClass().getDeclaredFields()) {
            //获取字段对应的注解
            PropertyAnnotation p = field.getDeclaredAnnotation(PropertyAnnotation.class);
            if (p != null) {
                // 获取Field的值:
                Object value = field.get(payParamInfo);
                // 数字类型
                if (value instanceof BigDecimal) {
                    String s = value.toString();
                    if (s.contains(".")) {
                        s = s.replace(".", "");
                    }
                    int Length = p.maxlen();
                    String format = StringUtils.leftPad(s, Length, p.fillpadding());
                    sb.append(format);
                }else if (value instanceof LocalDateTime){
                    //日期时间格式
                    String format = LocalDateTimeUtil.format((LocalDateTime) value, DatePattern.NORM_DATETIME_PATTERN);
                    //format.replaceAll("-", "").replaceAll(" ","").replaceAll(":","");
                    format = StringUtils.replace(format, "-", "");
                    format = StringUtils.replace(format, " ", "");
                    format = StringUtils.replace(format, ":", "");
                    sb.append(format);
                }else{
                    String format = StringUtils.leftPad(value.toString(), p.maxlen(), p.fillpadding());
                    sb.append(format);
                }
            }
        }
        return sb.toString();
    }

测试

public class TestMain {
    public static void main(String[] args) throws IllegalAccessException {
        PayParamInfo payParamInfo=new PayParamInfo();
        payParamInfo.setPayAmount(new BigDecimal("10.01"));
        payParamInfo.setPayNum(1);
        payParamInfo.setPayDateTime(LocalDateTime.now());
        payParamInfo.setPayTitle("测试订单");
        //格式化参数
        System.out.println("拼接的参数:"+payParamInfo.FormatParams(payParamInfo));
    }
}