{"id":207070,"date":"2025-07-08T08:26:09","date_gmt":"2025-07-08T00:26:09","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207070\/"},"modified":"2025-07-08T08:26:09","modified_gmt":"2025-07-08T00:26:09","slug":"io-reader-%e5%8f%af%e4%bb%a5%e6%8e%a5%e5%8f%97%e6%96%87%e4%bb%b6%e6%8f%8f%e8%bf%b0%e7%ac%a6%e5%90%97%ef%bc%9f-json-%e8%be%93%e5%85%a5%e6%84%8f%e5%a4%96%e7%bb%93%e6%9d%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207070\/","title":{"rendered":"io.Reader \u53ef\u4ee5\u63a5\u53d7\u6587\u4ef6\u63cf\u8ff0\u7b26\u5417\uff1f \u201cJSON \u8f93\u5165\u610f\u5916\u7ed3\u675f\u201d"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> io.Reader \u53ef\u4ee5\u63a5\u53d7\u6587\u4ef6\u63cf\u8ff0\u7b26\u5417\uff1f \u201cJSON \u8f93\u5165\u610f\u5916\u7ed3\u675f\u201d<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-19 20:36:34<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

Golang<\/span>\u4e0d\u77e5\u9053\u5927\u5bb6\u662f\u5426\u719f\u6089\uff1f\u4eca\u5929\u6211\u5c06\u7ed9\u5927\u5bb6\u4ecb\u7ecd\u300aio.Reader \u53ef\u4ee5\u63a5\u53d7\u6587\u4ef6\u63cf\u8ff0\u7b26\u5417\uff1f \u201cJSON \u8f93\u5165\u610f\u5916\u7ed3\u675f\u201d\u300b<\/span>\uff0c\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u4f1a\u8bb2\u5230<\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u5728\u770b\u5b8c\u672c\u7bc7\u6587\u7ae0\u540e\uff0c\u6709\u66f4\u597d\u7684\u5efa\u8bae\u6216\u8005\u53d1\u73b0\u54ea\u91cc\u6709\u95ee\u9898\uff0c\u5e0c\u671b\u5927\u5bb6\u90fd\u80fd\u79ef\u6781\u8bc4\u8bba\u6307\u51fa\uff0c\u8c22\u8c22\uff01\u5e0c\u671b\u6211\u4eec\u80fd\u4e00\u8d77\u52a0\u6cb9\u8fdb\u6b65\uff01<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u5728\u5c06\u6253\u5f00\u6587\u4ef6\u63cf\u8ff0\u7b26\u4ece os.create() \u4f20\u9012\u5230\u63a5\u53d7\u7c7b\u578b io.reader \u7684\u51fd\u6570\u5e76\u8fd0\u884c io.copy(b.bytes(), reader) \u540e\uff0c\u6709\u6548 json \u7684 json.unmarshal<\/code> \u5931\u8d25<\/p>\n

\u4ee5\u4e0b\u4ee3\u7801\u5757\u4e2d\u7684 read()<\/code> \u65b9\u6cd5\u662f\u5426\u6b63\u786e\u5b9e\u73b0\uff1f io.reader<\/code> \u5305\u88c5\u4e86 read<\/code> \u65b9\u6cd5\uff0c\u4f46\u5c06\u5411\u5176\u4f20\u9012\u4e00\u4e2a\u6253\u5f00\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u8bfb\u53d6<\/em>\u6587\u4ef6\u4e3a\u5b57\u8282\uff0c\u5141\u8bb8 io.copy(b.bytes(), reader) \u5c06\u6570\u636e\u590d\u5236\u5230 var\u4e59\uff1f <\/p>\n

\u662f\u5426\u6709\u66f4\u597d\u7684\u65b9\u6cd5\u5728\u4e0d\u4f7f\u7528 ioutil.readall<\/code> \u7684\u60c5\u51b5\u4e0b\u6267\u884c\u6b64\u64cd\u4f5c\uff1f<\/p>\n

    \n
  1. \u5df2\u9a8c\u8bc1 json \u5b8c\u5168\u6709\u6548\u3002\u4f7f\u7528 jq \u548c 3 \u4e2a\u5728\u7ebf json \u9a8c\u8bc1\u5668\u8fdb\u884c\u9a8c\u8bc1\u3002<\/li>\n
  2. \u9a8c\u8bc1\u6570\u636e\u5b9e\u9645\u4e0a\u5df2\u901a\u8fc7\u53e6\u4e00\u4e2a\u5b9e\u73b0 io.write \u7684\u51fd\u6570\u6210\u529f\u5199\u5165\u6587\u4ef6\u3002<\/li>\n
  3. \u5df2\u9a8c\u8bc1 ioutil.readall<\/code> \u53ef\u4ee5\u5c06 json \u8bfb\u53d6\u4e3a\u5b57\u8282\uff0c\u56e0\u6b64\u6211\u8ba4\u4e3a\u6240\u4f7f\u7528\u7684\u65b9\u6cd5\u5b9e\u65bd\u4e0d\u6b63\u786e\u3002 <\/li>\n<\/ol>\n

    ** \u8fd9\u4e0d\u662f\u6211\u7684\u4ee3\u7801\uff0c\u6211\u6b63\u5728\u5bf9\u5176\u4ed6\u4eba\u7f16\u5199\u7684\u4ee3\u7801\u8fdb\u884c\u6545\u969c\u6392\u9664\uff0c\u4f46\u8be5\u4eba\u65e0\u6cd5\u56de\u7b54\u4efb\u4f55\u95ee\u9898 **<\/p>\n

    \u6211\u6709\u4e00\u4e2a json \u6587\u4ef6 collected_data.json<\/code>\u3002<\/p>\n

    \u8be5\u6587\u4ef6\u662f\u4f7f\u7528 os.create \u521b\u5efa\u7684 <\/p>\n

    file, err := os.create(\"\/var\/log\/collected_data.json\")\n<\/pre>\n
    \u914d\u7f6e\u4e86\u4e00\u4e2a\u7ed3\u6784\u4f53\uff0c\u5b83\u5c06 file<\/code> \u8bbe\u7f6e\u4e3a datastore<\/code>\uff1a<\/p>\n
    profiler := &collectors.systemprofiler{\n  datastore:         file,\n  networkinterfaces: interfaces,\n  apiurl:            *apiurl,\n  runonce:           *runonce,\n  systag:            *systag,\n}\n<\/pre>\n
    \u7136\u540e\u6211\u4eec\u8fd0\u884c gather()<\/code> \u65b9\u6cd5\u3002<\/p>\n
    err = profiler.send(output)\nif err != nil {\n  log.error(err)\n}\n<\/pre>\n
    send()<\/code> \u65b9\u6cd5\u5b9e\u73b0 systemprofiler \u7ed3\u6784\uff1a<\/p>\n
    func (s *systemprofiler) send(profile *systemprofile) error {...}\n<\/pre>\n
    \u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u4e00\u5207\u6b63\u5e38\uff0c\u76f4\u5230\u6211\u4eec\u5c1d\u8bd5\u4ece \/var\/log\/collected_data.json<\/code> \u8bfb\u53d6\u548c\u89e3\u7ec4\u6570\u636e\u7684\u4ee3\u7801\u90e8\u5206\u4e3a\u6b62\u3002<\/p>\n
    \u5728\u8fd9\u4e2a send()<\/code> \u65b9\u6cd5\u4e2d\uff0c\u6211\u4eec\u5c1d\u8bd5\u5728\u4e24\u79cd\u60c5\u51b5\u4e0b\u8bfb\u53d6\u6587\u4ef6 \/var\/log\/collected_data.json<\/code>\u3002<\/p>\n
    \u7b2c\u4e00\uff0c\u5982\u679c\u6587\u4ef6\u4e0d\u4e3a\u7a7a\uff0c\u6211\u4eec\u8bfb\u53d6\u8be5\u6587\u4ef6\uff0c\u5e76\u7528\u5b83\u505a\u4e00\u4e9b\u4e8b\u60c5\uff08\u6b64\u5904\u672a\u663e\u793a\uff09\u3002<\/p>\n
    data, err := store.read(s.datastore)\nif err != nil {\n  log.print(\"i couldn't read the datastore\")\n  return err\n}\n<\/pre>\n
    \u7b2c\u4e8c\uff0c\u5982\u679c\u6587\u4ef6\u4e0d\u662f<\/em>\u4e3a\u7a7a\uff0c\u6211\u4eec\u5c06\u6570\u636e\u5199\u5165\u6587\u4ef6\uff0c\u7136\u540e\u7acb\u5373\u5c06\u5176\u8bfb\u56de\u5e76\u89e3\u7ec4\u4ee5\u6ee1\u8db3\u7a0d\u540e\u5728\u6bd4\u8f83\u7684\u6570\u636e\u4e4b\u95f4\u6267\u884c reflect.deepequal<\/code> \u7684\u51fd\u6570\u4ee5\u53ca\u5199\u5165\u6587\u4ef6\u7684\u6570\u636e\u3002 <\/p>\n
    \u5728\u8fd9\u4e24\u79cd\u60c5\u51b5\u4e0b\uff0cread()<\/code> \u65b9\u6cd5\u90fd\u4f1a\u8fd4\u56de\u201cjson \u8f93\u5165\u610f\u5916\u7ed3\u675f\u201d\uff0c\u6587\u4ef6 \/var\/log\/collected_data.json<\/code> \u4e2d\u5305\u542b\u6709\u6548\u7684 json\u3002\u7528\u4e8e\u5199\u5165\u6570\u636e\u7684\u65b9\u6cd5\u5de5\u4f5c\u5f97\u5f88\u597d\u3002<\/p>\n
    {\"level\":\"info\",\"msg\":\"i couldn't read the datastore\",\"time\":\"2019-08-02t02:26:42-04:00\"}\n{\"level\":\"error\",\"msg\":\"unexpected end of json input\",\"time\":\"2019-08-02t02:26:42-04:00\"}<\/pre>\n
    read()<\/code> \u65b9\u6cd5\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
    \/\/ read reads json data from an io.reader\nfunc read(reader io.reader) (interface{}, error) {\n  var data interface{}\n  var b bytes.buffer\n  io.copy(&b, reader)\n\n  err := json.unmarshal(b.bytes(), &data)\n    if err != nil {\n      return nil, err\n    }\n  return data, nil\n}\n<\/pre>\n
    \u9884\u671f\u7ed3\u679c\uff1a<\/p>\n
    \u6709\u6548\u7684 json \u4ece io.reader \u7c7b\u578b\u7684 reader \u590d\u5236\u5230 bytes.buffer \u7c7b\u578b\u7684 b\uff0c\u6210\u529f\u89e3\u7ec4\u5e76\u8fd4\u56de\u3002 <\/p>\n
    \u5b9e\u9645\u7ed3\u679c\uff1a {“level”:”error”,”msg”:”json \u8f93\u5165\u610f\u5916\u7ed3\u675f”,”time”:”2019-08-02t02:26:42-04:00″}<\/p>\n
    \u4e3a\u4e86\u56de\u7b54\u8bc4\u8bba\u4e2d\u63d0\u51fa\u7684\u95ee\u9898\uff0c\u4ee5\u4e0b\u662f send()<\/code> \u51fd\u6570\u5185\u7684\u4ee3\u7801\u5757\uff1a<\/p>\n
    var storedProfile SystemProfile\n\n    check := store.IsEmpty(s.DataStore)\n\n    if check == false {\n        log.Print(\"Data Store Exists\") \n        \/\/ If there is data stored, read it\n        data, err := store.Read(s.DataStore)\n        if err != nil {\n            return err\n        }\n        \/\/var tmp SystemProfile\n        err = mapstructure.Decode(data, &storedProfile)\n        if err != nil {\n            return err\n        }\n    } else {\n        log.Print(\"Data Store Doesn't Exist\")\n        \/\/ If the data store is empty, write to it\n        err := store.Write(s.DataStore, profile)\n        if err != nil {\n            return err\n        }\n        data, err := store.Read(s.DataStore)\n        if err != nil {\n            log.Print(\"I couldn't read the datastore\")\n            return err\n        }\n        err = mapstructure.Decode(data, &storedProfile)\n        if err != nil {\n            log.Print(\"I couldn't decode the json to a map\")\n            return err\n        }\n\n        body, err := json.Marshal(profile)\n        if err != nil {\n            return err\n        }\n        _, err = client.Post(s.ApiURL, \"application\/json\", bytes.NewBuffer(body)) \/\/ TODO: Handle response from API here\n        log.Print(client.LogString())\n    }\n\nif !reflect.DeepEqual(storedProfile, profile ) {\n        \/\/ If what's in the data store and what has been collected are different,\n        \/\/ write the recently collected data to the data store and send it out to the API\n        store.Write(s.DataStore, profile)\n        body, err := json.Marshal(profile)\n        if err != nil {\n            return err\n        }\n        _, err = client.Post(s.ApiURL, \"application\/json\", bytes.NewBuffer(body)) \/\/ TODO: Handle response from API here\n        if err != nil {\n            return err\n        }\n        log.Print(client.LogString())\n    }\n<\/pre>\n
     <\/p>\n
    \u89e3\u51b3\u65b9\u6848<\/h2>\n
     <\/p>\n
    \u8fd9\u4e2a\u95ee\u9898\u7684\u7b54\u6848\u662f\u80af\u5b9a\u7684\u3002 *os.file<\/code> \u53ef\u4ee5\u7528\u4f5c io.reader<\/code>\u3002<\/p>\n
    \u95ee\u9898\u5728\u4e8e\u5e94\u7528\u7a0b\u5e8f\u5c06\u6570\u636e\u5199\u5165\u6587\u4ef6\uff0c\u7136\u540e\u5c1d\u8bd5\u4ece\u6587\u4ef6\u4e2d\u8bfb\u53d6\u76f8\u540c\u7684\u6570\u636e\uff0c\u800c\u4e0d\u67e5\u627e\u6570\u636e\u5199\u5165\u7684\u4f4d\u7f6e\u3002<\/p>\n
    \u901a\u8fc7\u5728\u8c03\u7528 store.write \u4e4b\u540e\u3001\u8c03\u7528 store.read \u4e4b\u524d\u6dfb\u52a0\u4ee5\u4e0b\u4ee3\u7801\u6765\u4fee\u590d\u8be5\u95ee\u9898\u3002<\/p>\n
    if _, err := s.DataStore.Seek(io.SeekStart, 0); err != nil {\n     return err\n }<\/pre>\n
    \u4eca\u5929\u5173\u4e8e\u300aio.Reader \u53ef\u4ee5\u63a5\u53d7\u6587\u4ef6\u63cf\u8ff0\u7b26\u5417\uff1f \u201cJSON \u8f93\u5165\u610f\u5916\u7ed3\u675f\u201d\u300b\u7684\u5185\u5bb9\u5c31\u4ecb\u7ecd\u5230\u8fd9\u91cc\u4e86\uff0c\u662f\u4e0d\u662f\u5b66\u8d77\u6765\u4e00\u76ee\u4e86\u7136\uff01\u60f3\u8981\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u5185\u5bb9\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207070","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=207070"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207070\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}