枚举，注解 ，反射

package com.itep.mt.common.annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
@Retention(RetentionPolicy.RUNTIME)
public @interface ParamField{
  int    sort()   default 0;           //字段排序
  int    len()    default 0;           //报文长度
  LenType lenType() default LenType.FIXED; //长度类型
  Charset charset() default Charset.DYNAMIC;
  Encode encode() default Encode.ASC;  //编码格式
  public enum Encode{
    ASC,   //ASCII编码
    BCD,   //二进码十进数
    HEX    //十六进制码
  }
  public enum Charset{
    GBK("GBK"),   //GBK
    UTF_8("UTF-8"),   //UTF_8
    DYNAMIC("dynamic");   //动态编码
    private String charset;
    private Charset(String charset) {
      this.charset=charset;
    }
    public String value() {
      return this.charset;
    }
  }
  public enum LenType{
    FIXED,   //固定
    DYNAMIC    //动态
  }
}

package com.itep.mt.infoviewer.dto;
import com.itep.mt.common.annotation.ParamField;
import com.itep.mt.common.dto.BaseDTO;
/**
 * Created by xianghui on 2019/9/12.
 */
public class PDFSign2DTO extends BaseDTO {
    /**
     * pdf的签字页，从0开始
     */
    @ParamField(sort = 0, len = 1, encode = ParamField.Encode.BCD)
    private int page;
    /**
     * X：pdf的签字位置
     */
    @ParamField(sort = 1, len = 2, encode = ParamField.Encode.BCD)
    private int x;
    /**
     * Y：pdf的签字位置
     */
    @ParamField(sort = 2, len = 2, encode = ParamField.Encode.BCD)
    private int y;
    /**
     * W：pdf的签字区域宽度
     */
    @ParamField(sort = 3, len = 2, encode = ParamField.Encode.BCD)
    private int w;
    /**
     * H：pdf的签字区域高度
     */
    @ParamField(sort = 4, len = 2, encode = ParamField.Encode.BCD)
    private int h;
    /**
     * 超时时间
     */
    @ParamField(sort = 5, len = 1, encode = ParamField.Encode.BCD)
    private int timeOut;
    /**
     * 要播放的语音
     */
    @ParamField(sort = 6, len = 1, lenType = ParamField.LenType.DYNAMIC, encode = ParamField.Encode.ASC)
    private String voice;
    /**
     * 是否播放语音信息 0-表示不播放,1-表示播放默认,2-表示播放指定
     */
    @ParamField(sort = 7, len = 1, encode = ParamField.Encode.BCD)
    private int voiceType;
    /**
     * 界面上的提示信息
     */
    @ParamField(sort = 8, len = 1, lenType = ParamField.LenType.DYNAMIC, encode = ParamField.Encode.ASC)
    private String info;
    /**
     * 用户操作类型
     */
//    @ParamField(sort = 9, len = 1, encode = ParamField.Encode.BCD)
//    private int operateType;
    /**
     * 协议信息
     */
    @ParamField(sort = 9, len = 1, lenType = ParamField.LenType.DYNAMIC, encode = ParamField.Encode.ASC)
    private String pro;
    private int operateType;
    public int getPage() {
        return page;
    }
    public void setPage(int page) {
        this.page = page;
    }
    public int getX() {
        return x;
    }
    public void setX(int x) {
        this.x = x;
    }
    public int getY() {
        return y;
    }
    public void setY(int y) {
        this.y = y;
    }
    public int getW() {
        return w;
    }
    public void setW(int w) {
        this.w = w;
    }
    public int getH() {
        return h;
    }
    public void setH(int h) {
        this.h = h;
    }
    public int getTimeOut() {
        return timeOut;
    }
    public void setTimeOut(int timeOut) {
        this.timeOut = timeOut;
    }
    public String getVoice() {
        return voice;
    }
    public void setVoice(String voice) {
        this.voice = voice;
    }
    public int getVoiceType() {
        return voiceType;
    }
    public void setVoiceType(int voiceType) {
        this.voiceType = voiceType;
    }
    public String getInfo() {
        return info;
    }
    public void setInfo(String info) {
        this.info = info;
    }
    public int getOperateType() {
        return operateType;
    }
    public void setOperateType(int operateType) {
        this.operateType = operateType;
    }
    public String getPro() {
        return pro;
    }
    public void setPro(String pro) {
        this.pro = pro;
    }
    @Override
    public String toString() {
        return "PDFSign2DTO{" +
                "page=" + page +
                ", x=" + x +
                ", y=" + y +
                ", w=" + w +
                ", h=" + h +
                ", timeOut=" + timeOut +
                ", voice='" + voice + ''' +
                ", voiceType=" + voiceType +
                ", info='" + info + ''' +
//                ", operateType=" + operateType +
                ", pro='" + pro + ''' +
                '}';
    }
}