Question

我在我的节点应用程序中有几个json文件的文件夹（可能超过10个）我需要从验证方面读取它们并查找特定属性，如果此属性出现在多个json文件中则抛出错误，从绩效和效率方面

来做到这一点的最佳方式是什么？

例如我的文件夹名为plugins 并且所有json都构建如下

json1

{
  "action": [
    {
      "delete": {
        "path": "deleteFile",
         "providedAction":"Del" 
      },
    {
      "update": {
        "path": "updateFile",
         "providedAction":"UPD" 
      }

    }
  ]
}

这是有效的json ，因为 providedAction = add不存在在其他json **

json2

{
  "action": [
    {
      "add": {
        "path": "addFile",
         "providedAction":"Add" 
      }
    }
  ]
}

这是无效 json，因为 providedAction = UPD操作已经存在 JSON 3

{
      "action": [
        {
                  {
          "update": {
            "path": "updateFile",
             "providedAction":"UPD" 
          }
        }
      ]
    }

我需要验证只有这个json有动作“Del”，如果多个json有这个trow错误，它的建议是怎么做的？

Answer 1

好的，这是代码。如果你不明白的事情让我知道，我很乐意帮助你！

var glob = require("glob");
var fs = require("fs");

var _inArray = function(needle, haystack) {
  for(var k in haystack) {
    if(haystack[k] === needle) {
      return true;
    }
  }
  return false;
}

glob("json/*.json", function(err, files) { // read the folder or folders if you want: example json/**/*.json
  if(err) {
    console.log("cannot read the folder, something goes wrong with glob", err);
  }
  var matters = [];
  files.forEach(function(file) {
    fs.readFile(file, 'utf8', function (err, data) { // Read each file
      if(err) {
        console.log("cannot read the file, something goes wrong with the file", err);
      }
      var obj = JSON.parse(data);
      obj.action.forEach(function(crud) {
        for(var k in crud) {
          if(_inArray(crud[k].providedAction, matters)) {
            // do your magic HERE
            console.log("duplicate founded!");
            // you want to return here and cut the flow, there is no point in keep reading files.
            break;
          }
          matters.push(crud[k].providedAction);
        }
      })
    });
  });
});

JSON 1：

{"action": [
  {
    "delete": {
      "path": "deleteFile",
      "providedAction": "Del"
    }
  },
  {
    "update": {
      "path": "updateFile",
      "providedAction": "UPD"
    }
  }
]
}

JSON 2：

{
  "action": [
    {
      "add": {
        "path": "addFile",
        "providedAction": "Add"
      }
    }
  ]
}

JSON 3：

{
  "action": [
    {
      "update": {
        "path": "updateFile",
        "providedAction": "UPD"
      }
    }
  ]
}

Answer 2

不是我写过的最漂亮的代码，但现在是：

// Require the nodejs file system library
var fs = require('fs');
var path = '/usr/local/var/jsons';
var delCounter = 0;

// Readdir reads a path and gives an array of filenames
// to the callback handleFiles.
fs.readdir(path, handleFiles);

function handleFiles (err, files) {
    if (err) throw err;
    var i;
    var jsonFilePattern=/\.[json]+$/i;
    var fileName;
    var filePath;
    // Tells fs to read an utf-8 file.
    var fileReadOptions = {
        'encoding':'utf-8'
    };

    for (i = 0; i < files.length; ++i) {
        fileName = files[i];
        // Check if the file has a .json extension
        if (fileName.match(jsonFilePattern)) {
            filePath = path + '/' + fileName;
            // Open the file as utf-8 and call handleJsonFile back
            // when done reading.
            fs.readFile(filePath, fileReadOptions, handleJsonFile);
        }
    }
}

function handleJsonFile (err, data) {
    if (err) throw err;
    var dataObject = JSON.parse(data);
    var i;
    var action;
    // Loop through all possible action.
    for (i = 0; i < dataObject.action.length; ++i) {
        action = dataObject.action[i];
        if (action.delete &&
            action.delete.providedAction && 
            action.delete.providedAction === 'Del')
        {
            // If there is a 'Del', add it to the counter.
            ++delCounter;
        }
    }
    if (delCounter > 1) {
        throw new Exception('Jsons  not valid.');
    }
}

Answer 3

或许这样的事情，享受！ npm install glob

JSON 1

module.exports = {
  "action": [{
    "delete": {
      "path": "deleteFile",
      "action":"Del"
    }
  }]
}

CODE

(function() {
  var glob = require("glob");
  glob("path/to/*.js", function(er, files) {
    if(er) return;
    var x = 0;
    files.forEach(function(file) {
      require(file)['action'].forEach(function(act) {
        if(act.delete.action && act.delete.action == "Del") x++;
      });
    });
    if(x > 1) throw new Exception(""); // or something ja!
  });
})();

凌晨5点没有睡觉，抱歉如果我犯了错误，我只想告诉你的方式......不要复制粘贴！的xD。

Answer 4

使用现代语法，在这里减少和扩展可能会有很大帮助：

const files = readdirSync(path);
files.reduce((acc, curr) => {
  const file = JSON.parse(readFileSync(path.join(path, curr), 'utf8'));
  const merged = { ...acc, ...file };

  // Check for destructive merging.
  if (Object.keys(file).length + Object.keys(acc).length > Object.keys(merged).length) {
    throw Error('Destructive merge of JSON files.');
  }

  return merged;
}, {});

从节点文件夹中获取所有json文件，并在里面找到特定的attr

4 个答案: