com.github.xingshuangs.iot.protocol.s7.model.Datum Maven / Gradle / Ivy

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package com.github.xingshuangs.iot.protocol.s7.model;


import com.github.xingshuangs.iot.protocol.common.IObjectByteArray;
import com.github.xingshuangs.iot.protocol.s7.enums.EFunctionCode;
import com.github.xingshuangs.iot.protocol.s7.enums.EMessageType;
import com.github.xingshuangs.iot.protocol.common.buff.ByteWriteBuff;
import lombok.Data;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

/**
 * 数据
 *
 * @author xingshuang
 */
@Data
public class Datum implements IObjectByteArray {

    /**
     * 数据项
     */
    private List returnItems = new ArrayList<>();

    @Override
    public int byteArrayLength() {
        if (this.returnItems.isEmpty()) {
            return 0;
        }
        int sum = 0;
        for (ReturnItem returnItem : this.returnItems) {
            sum += returnItem.byteArrayLength();
        }
        return sum;
    }

    @Override
    public byte[] toByteArray() {
        if (this.returnItems.isEmpty()) {
            return new byte[0];
        }
        ByteWriteBuff buff = ByteWriteBuff.newInstance(this.byteArrayLength());
        for (ReturnItem returnItem : this.returnItems) {
            buff.putBytes(returnItem.toByteArray());
        }
        return buff.getData();
    }

    /**
     * 添加数据项
     *
     * @param item 项
     */
    public void addItem(ReturnItem item) {
        this.returnItems.add(item);
    }

    /**
     * 批量添加数据项
     *
     * @param items 数据项列表
     */
    public void addItem(Collection items) {
        this.returnItems.addAll(items);
    }

    /**
     * 根据消息类型和功能码，对字节数组数据进行解析
     *
     * @param data         字节数组数据
     * @param messageType  头部的消息类型
     * @param functionCode 参数部分的功能码
     * @return Datum
     */
    public static Datum fromBytes(final byte[] data, EMessageType messageType, EFunctionCode functionCode) {
        Datum datum = new Datum();
        if (data.length == 0) {
            return datum;
        }
        int offset = 0;
        byte[] remain = data;
        while (true) {
            ReturnItem dataItem;
            // 对写操作的响应结果进行特殊处理
            if (EMessageType.ACK_DATA == messageType && EFunctionCode.WRITE_VARIABLE == functionCode) {
                dataItem = ReturnItem.fromBytes(data);
            } else {
                dataItem = DataItem.fromBytes(remain);
            }

            datum.returnItems.add(dataItem);
            offset += dataItem.byteArrayLength();
            if (offset >= data.length) {
                break;
            }
            remain = Arrays.copyOfRange(data, offset, data.length);
        }
        return datum;
    }

    /**
     * 创建数据Datum
     *
     * @param dataItems 数据项
     * @return 数据对象Datum
     */
    public static Datum createDatum(Collection dataItems) {
        Datum datum = new Datum();
        datum.addItem(dataItems);
        return datum;
    }
}