处理网关获取升级包的请求(二)

继续啃硬骨头，真香

由于要再写一个方法getOtaPackageCallbackByGateway()，这又是一个难题，写代码是不可能的，这辈子都不可能写代码，只有ctrl+c ctrl+v 这种办法，才能勉强生存。

首先复制getOtaPackageCallback()，改名为getOtaPackageCallbackByGateway()，变成下面这样：

private void getOtaPackageCallbackByGateway(ChannelHandlerContext ctx, MqttPublishMessage mqttMsg, int msgId, Matcher fwMatcher, OtaPackageType type) {
    String payload = mqttMsg.content().toString(UTF8);
    int chunkSize = StringUtils.isNotEmpty(payload) ? Integer.parseInt(payload) : 0;
    String requestId = fwMatcher.group("requestId");
    int chunk = Integer.parseInt(fwMatcher.group("chunk"));

    if (chunkSize > 0) {
        this.chunkSizes.put(requestId, chunkSize);
    } else {
        chunkSize = chunkSizes.getOrDefault(requestId, 0);
    }

    if (chunkSize > context.getMaxPayloadSize()) {
        sendOtaPackageError(ctx, PAYLOAD_TOO_LARGE);
        return;
    }

    String otaPackageId = otaPackSessions.get(requestId);

    if (otaPackageId != null) {
        sendOtaPackage(ctx, mqttMsg.variableHeader().packetId(), otaPackageId, requestId, chunkSize, chunk, type);
    } else {
        TransportProtos.SessionInfoProto sessionInfo = deviceSessionCtx.getSessionInfo();
        TransportProtos.GetOtaPackageRequestMsg getOtaPackageRequestMsg = TransportProtos.GetOtaPackageRequestMsg.newBuilder()
                .setDeviceIdMSB(sessionInfo.getDeviceIdMSB())
                .setDeviceIdLSB(sessionInfo.getDeviceIdLSB())
                .setTenantIdMSB(sessionInfo.getTenantIdMSB())
                .setTenantIdLSB(sessionInfo.getTenantIdLSB())
                .setType(type.name())
                .build();
        transportService.process(deviceSessionCtx.getSessionInfo(), getOtaPackageRequestMsg,
                new OtaPackageCallback(ctx, msgId, getOtaPackageRequestMsg, requestId, chunkSize, chunk));
    }
}

仔细观察，前面一大坨是在提取参数，我们需要的参数肯定跟它不一样，我们请求的参数有4个，分别是requestId、chunk、chunkSize、deviceName。我们先修改提取参数部分，我修改后如下：

@Data
private class GatewayOtaPackageRequestDTO {
    private String deviceName;
    private Integer chunkSize;
}

private void getOtaPackageCallbackByGateway(ChannelHandlerContext ctx, MqttPublishMessage mqttMsg, int msgId, Matcher fwMatcher, OtaPackageType type) {

    String requestId = fwMatcher.group("requestId");
    int chunk = Integer.parseInt(fwMatcher.group("chunk"));

    String payload = mqttMsg.content().toString(UTF8);
    Gson gson = new Gson();

    GatewayOtaPackageRequestDTO dto = null;
    try {
        dto = gson.fromJson(payload, GatewayOtaPackageRequestDTO.class);
    } catch (JsonSyntaxException e){
        sendOtaPackageErrorToGateway(ctx, msgId, requestId, "解析JSON出错，请求负载不合法，负载示例：{deviceName:"SN-001", chunkSize:512}", type);
        return;
    }

    if(dto == null) {
        sendOtaPackageErrorToGateway(ctx, msgId, requestId, "请求没有负载，负载示例：{deviceName:"SN-001", chunkSize:512}", type);
        return;
    }

    Integer chunkSize = dto.getChunkSize();
    String deviceName = dto.getDeviceName();

    if(chunkSize == null) {
        sendOtaPackageErrorToGateway(ctx, msgId, requestId, "请求负载缺少chunkSize，负载示例：{deviceName:"SN-001", chunkSize:512}", type);
        return;
    }

    if(deviceName == null) {
        sendOtaPackageErrorToGateway(ctx, msgId, requestId, "请求负载缺少deviceName，负载示例：{deviceName:"SN-001", chunkSize:512}", type);
        return;
    }

    if (chunkSize > 0) {
        this.chunkSizes.put(requestId, chunkSize);
    } else {
        chunkSize = chunkSizes.getOrDefault(requestId, 0);
    }

    if (chunkSize > context.getMaxPayloadSize()) {
        sendOtaPackageError(ctx, PAYLOAD_TOO_LARGE);
        return;
    }
    

    String otaPackageId = otaPackSessions.get(requestId);

    if (otaPackageId != null) {
        sendOtaPackage(ctx, mqttMsg.variableHeader().packetId(), otaPackageId, requestId, chunkSize, chunk, type);
    } else {
        TransportProtos.SessionInfoProto sessionInfo = deviceSessionCtx.getSessionInfo();
        TransportProtos.GetOtaPackageRequestMsg getOtaPackageRequestMsg = TransportProtos.GetOtaPackageRequestMsg.newBuilder()
                .setDeviceIdMSB(sessionInfo.getDeviceIdMSB())
                .setDeviceIdLSB(sessionInfo.getDeviceIdLSB())
                .setTenantIdMSB(sessionInfo.getTenantIdMSB())
                .setTenantIdLSB(sessionInfo.getTenantIdLSB())
                .setType(type.name())
                .build();
        transportService.process(deviceSessionCtx.getSessionInfo(), getOtaPackageRequestMsg,
                new OtaPackageCallback(ctx, msgId, getOtaPackageRequestMsg, requestId, chunkSize, chunk));
    }
}

sendOtaPackageErrorToGateway()方法暂时不用管，它的作用是向网关发送错误响应，虽然多了很多判断，搞得代码多出不少行，但也是没有办法，反正是复制粘贴而来，也不费什么工夫。

这篇文章字数感觉挺多了，下一篇继续。