如何遍历JSON文件？

Question

The JSON I have is mentioned below :-

{   head: {
    link: [],
    vars: [
      "CompanyName",
      "Company_Name",
      "Foundation_URI",
      "Foundation_Name",
      "Latitude",
      "Longitude"
    ]   },   results: {
    distinct: false,
    ordered: true,
    bindings: [
      {
        CompanyName: {
          type: "uri",
          value: "http://dbpedia.org/resource/United_Christian_Broadcasters"
        },
        Company_Name: {
          type: "literal",
          xml:lang: "en",
          value: "United Christian Broadcasters"
        },
        Foundation_URI: {
          type: "uri",
          value: "http://dbpedia.org/resource/Christchurch"
        },
        Foundation_Name: {
          type: "literal",
          xml:lang: "en",
          value: "Christchurch"
        },
        Latitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "-43.52999877929688"
        },
        Longitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "172.6202850341797"
        }
      },
      {
        CompanyName: {
          type: "uri",
          value: "http://dbpedia.org/resource/United_Christian_Broadcasters"
        },
        Company_Name: {
          type: "literal",
          xml:lang: "en",
          value: "UCB Media"
        },
        Foundation_URI: {
          type: "uri",
          value: "http://dbpedia.org/resource/Christchurch"
        },
        Foundation_Name: {
          type: "literal",
          xml:lang: "en",
          value: "Christchurch"
        },
        Latitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "-43.52999877929688"
        },
        Longitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "172.6202850341797"
        }
      },
      {
        CompanyName: {
          type: "uri",
          value: "http://dbpedia.org/resource/Kathmandu_%28company%29"
        },
        Company_Name: {
          type: "literal",
          xml:lang: "en",
          value: "Kathmandu"
        },
        Foundation_URI: {
          type: "uri",
          value: "http://dbpedia.org/resource/Christchurch"
        },
        Foundation_Name: {
          type: "literal",
          xml:lang: "en",
          value: "Christchurch"
        },
        Latitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "-43.52999877929688"
        },
        Longitude: {
          type: "typed-literal",
          datatype: "http://www.w3.org/2001/XMLSchema#float",
          value: "172.6202850341797"
        }
      }
    ]   } }

I want to know that how can I traverse this JSON to get the values of the appropriate variables as mentioned in the JSON file. I would like to know this with respect to JavaScript as well as Java. Please let me know how to traverse this JSON so as to get data easily.

Answer 1

This is not a JSON string but luckily a YAML standrd format.

You can use YAML library to transverse your jSON-like string

Answer 2

Here is a rather simple tree traversal routine:

function traverse(o) {
  if( o instanceof Object ) {
    for( key in o ) {
      traverse(o[key]);
    }
  }
  else if( o instanceof Array ) {
    for( value in o ) {
      traverse(value);
    }
  }
  else {
    console.log(o);
  }
}
var q = { name : 'me', data : [ { a: 'a1', b: 'b1' }, { a: 'a2', b: 'b2'} ] };
traverse(q);

However, I think this is not quite what you're looking for. Please clarify and I will update my answer accordingly.

Answer 3

Following is a simple traversing of JSON object, this should help you undersatnd your JSON object normal traversing. Check the https://github.com/substack/js-traverse link for a detailed tutorial for complex traversing of any javascript object

<script language="javascript"> 

var emp = {"details" : [
             {
             "Name" : "Nitin1",
             "Salary" : 10000, 
             "DOJ" : "16th Sept 2010"
             }
            ,

             {"Name" : "Abhijit2", 
             "Salary" : 5000, 
             "DOJ" : "15th Sept 2010"}
            ,

             {"Name" : "Nilesh", 
             "Salary" : 50000, 
             "DOJ" : "10th Sept 2010"}

            ]
    };

document.writeln("<table border='1'><tr><td>Name</td><td>Salary</td><td>DOJ</td></tr>");
var i=0;
for(i=0;i<emp.details.length; i++)
{
  document.writeln("<tr><td>" + emp.details[i].Name + "</td>");
  document.writeln("<td>" + emp.details[i].Salary +"</td>");
  document.writeln("<td>" + emp.details[i].DOJ +"</td></tr>");
}
document.writeln("</table>");


</script>

Answer 4

If you only want to retrieve particular values - you do not need to traverse the entire JSON file.

This can be done in Javascript as follows:

Declared JSON variable:

var myJSONObject = {"bindings": [
        {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"},
        {"ircEvent": "PRIVMSG", "method": "deleteURI", "regex": "^delete.*"},
        {"ircEvent": "PRIVMSG", "method": "randomURI", "regex": "^random.*"}
    ]
};

Fetch a particular value:

myJSONObject.bindings[0].method    // "newURI"

For a full reference you can go here .

I do not use Java myself, but XML.java (documentation available here ) allows you to convert the JSON into XML. Parsing an XML is easy - you will find plenty of tutorials on it for Java such as:

http://www.seas.gwu.edu/~simhaweb/java/xml/xml.html

Cheers!