Protobuf 实例（java）

妖狐艹你老母 2022-10-12 04:24 202阅读 0赞

最近项目中需要使用Protobuf作为设备端到云端通信的数据压缩协议，特此记录便于日后查阅。

maven依赖如下：

<dependency>
        <groupId>com.google.protobuf</groupId>
        <artifactId>protobuf-java</artifactId>
        <version>3.15.8</version>
    </dependency>

protobuf文件名为 d\_cook\_records.proto，内容如下：

syntax = "proto3";
    import "google/protobuf/any.proto";
    // option java_package="com.galanz.iot.content.restapi.model.proto";
    option java_outer_classname="DCookRecordsProto";
    
    // DCookRecords
    message DCookRecords {
        repeated DCookRecord records = 1;
    }
    // DCookRecord
    message DCookRecord {
    	int32 record_type = 1;
    	string record_producer = 2;
        int64 record_start_time = 3;
        int64 record_end_time = 4;
        google.protobuf.Any record_value = 5;
    }
    // ProgramRecordValue record_type = 1 or 2
    message ProgramRecordValue {
        string content_code = 1;
        int32 content_version = 2;
        string dimension = 3;
        repeated TempRecord oven_temp_list = 4;
        repeated TempRecord probe_temp_list = 5;
    }
    // RecipeRecordValue record_type = 3
    message RecipeRecordValue {
    	int64 recipe_id = 1;
        string recipe_code = 2;
        string dimension = 3;
        repeated TempRecord oven_temp_list = 4;
        repeated TempRecord probe_temp_list = 5;
    }
    message TempRecord {
    	int32 temp = 1;
    	int64 timestamp = 2;
    }

**注：protobuf属性解释可以参照另一篇文章，传送门：[Protobuf 属性解释][Protobuf]**

在Java中的写法，代码如下：

@Override
    public Boolean insertRecord(String record) throws InvalidProtocolBufferException {
        //ProtoBuf组装
        DCookRecordsProto.ProgramRecordValue.Builder value1 = DCookRecordsProto.ProgramRecordValue.newBuilder();
        value1.setContentCode("xxx")
                .setContentVersion(1)
                .setDimension("xx#xx");
        for (int i = 0; i < 2; i++) {
            DCookRecordsProto.TempRecord.Builder tempRecord = DCookRecordsProto.TempRecord.newBuilder();
            tempRecord.setTemp(100 + i + 1).setTimestamp(System.currentTimeMillis());
            value1.addOvenTempList(tempRecord);
            value1.addProbeTempList(tempRecord);
        }
        DCookRecordsProto.DCookRecord.Builder cookRecord = DCookRecordsProto.DCookRecord.newBuilder();
        cookRecord.setRecordType(1)
                .setRecordProducer("d")
                .setRecordStartTime(System.currentTimeMillis())
                .setRecordEndTime(System.currentTimeMillis())
                .setRecordValue(Any.pack(value1.build()));
        DCookRecordsProto.DCookRecords.Builder cookRecords = DCookRecordsProto.DCookRecords.newBuilder();
        cookRecords.addRecords(cookRecord);
        byte[] bytes = cookRecords.build().toByteArray();
        //Base64 Encoded
        String encoded = Base64.getEncoder().encodeToString(bytes);
        System.out.println("---------encoded----------");
        System.out.println(encoded);
        //ProtoBuf反解析
        final String did = LoginUtils.getDid();
        List<RmCookRecordPo> recordPoList = Lists.newArrayList();
        byte[] decoded = Base64.getDecoder().decode(record);
        DCookRecordsProto.DCookRecords records = DCookRecordsProto.DCookRecords.parseFrom(decoded);
        if (!(ObjectUtils.isEmpty(records) || CollectionUtils.isEmpty(records.getRecordsList()))) {
            for (DCookRecordsProto.DCookRecord record1 : records.getRecordsList()) {
                RmCookRecordPo recordPo = new RmCookRecordPo();
                recordPo.setDid(did);
                if (record1.getRecordStartTime() > 0) {
                    Instant instant = Instant.ofEpochMilli(record1.getRecordStartTime());
                    recordPo.setRecordStartTime(LocalDateTime.ofInstant(instant, ZoneId.systemDefault()));
                }
                if (record1.getRecordEndTime() > 0) {
                    Instant instant = Instant.ofEpochMilli(record1.getRecordEndTime());
                    recordPo.setRecordEndTime(LocalDateTime.ofInstant(instant, ZoneId.systemDefault()));
                }
                recordPo.setRecordProducer(record1.getRecordProducer());
                recordPo.setRecordType(record1.getRecordType());
                if (record1.getRecordType() == 1 || record1.getRecordType() == 2) {
                    DCookRecordsProto.ProgramRecordValue recordValue = record1.getRecordValue()
                            .unpack(DCookRecordsProto.ProgramRecordValue.class);
                    ProgramRecordValue programRecordValue = new ProgramRecordValue();
                    programRecordValue.setContentCode(recordValue.getContentCode());
                    programRecordValue.setContentVersion(recordValue.getContentVersion());
                    programRecordValue.setDimension(recordValue.getDimension());
                    if (!CollectionUtils.isEmpty(recordValue.getOvenTempListList())) {
                        List<TempRecord> tempRecordList = Lists.newArrayList();
                        for (DCookRecordsProto.TempRecord ovenTemp : recordValue.getOvenTempListList()) {
                            TempRecord tempRecord = new TempRecord();
                            tempRecord.setTemp(ovenTemp.getTemp());
                            tempRecord.setTimestamp(ovenTemp.getTimestamp());
                            tempRecordList.add(tempRecord);
                        }
                        programRecordValue.setOvenTempListList(tempRecordList);
                    }
                    if (!CollectionUtils.isEmpty(recordValue.getProbeTempListList())) {
                        List<TempRecord> tempRecordList = Lists.newArrayList();
                        for (DCookRecordsProto.TempRecord protoTemp : recordValue.getProbeTempListList()) {
                            TempRecord tempRecord = new TempRecord();
                            tempRecord.setTemp(protoTemp.getTemp());
                            tempRecord.setTimestamp(protoTemp.getTimestamp());
                            tempRecordList.add(tempRecord);
                        }
                        programRecordValue.setProbeTempListList(tempRecordList);
                    }
                    recordPo.setRecordValue(JSONObject.toJSONString(programRecordValue));
                } else if (record1.getRecordType() == 2) {
                    DCookRecordsProto.RecipeRecordValue recordValue = record1.getRecordValue()
                            .unpack(DCookRecordsProto.RecipeRecordValue.class);
                    RecipeRecordValue recipeRecordValue = new RecipeRecordValue();
                    recipeRecordValue.setRecipeId(recordValue.getRecipeId());
                    recipeRecordValue.setRecipeCode(recordValue.getRecipeCode());
                    recipeRecordValue.setDimension(recordValue.getDimension());
                    if (!CollectionUtils.isEmpty(recordValue.getOvenTempListList())) {
                        List<TempRecord> tempRecordList = Lists.newArrayList();
                        for (DCookRecordsProto.TempRecord ovenTemp : recordValue.getOvenTempListList()) {
                            TempRecord tempRecord = new TempRecord();
                            tempRecord.setTemp(ovenTemp.getTemp());
                            tempRecord.setTimestamp(ovenTemp.getTimestamp());
                            tempRecordList.add(tempRecord);
                        }
                        recipeRecordValue.setOvenTempListList(tempRecordList);
                    }
                    if (!CollectionUtils.isEmpty(recordValue.getProbeTempListList())) {
                        List<TempRecord> tempRecordList = Lists.newArrayList();
                        for (DCookRecordsProto.TempRecord protoTemp : recordValue.getProbeTempListList()) {
                            TempRecord tempRecord = new TempRecord();
                            tempRecord.setTemp(protoTemp.getTemp());
                            tempRecord.setTimestamp(protoTemp.getTimestamp());
                            tempRecordList.add(tempRecord);
                        }
                        recipeRecordValue.setProbeTempListList(tempRecordList);
                    }
                    recordPo.setRecordValue(JSONObject.toJSONString(recipeRecordValue));
                }
                recordPoList.add(recordPo);
            }
        }
        //入库
        if (!CollectionUtils.isEmpty(recordPoList)) {
            baseMapper.batchInsertCookRecordList(recordPoList);
        }
        return true;
    }

到此 Protobuf 使用实例（java）介绍完成。

[Protobuf]: https://vegetable-chicken.blog.csdn.net/article/details/118442008