How would i compare two JSON files and get the specific objects which differs using C#?-CodePudding

I got two JSON files containing mostly identical data, but there might be objects that is only present in one of the files. How would i go about identifying these specific objects?

Example:
JSON 1:

[
  {
    "SourceLocation": "England",
    "DestinationLocation": "Spain",
    "DeliveryDate": "9/12"
  },
  {
    "SourceLocation": "England",
    "DestinationLocation": "Germany",
    "DeliveryDate": "9/12"
  }
]

JSON 2:

[
  {
    "SourceLocation": "England",
    "DestinationLocation": "Spain",
    "DeliveryDate": "9/12"
  },
  {
    "SourceLocation": "England",
    "DestinationLocation": "Germany",
    "DeliveryDate": "9/12"
  },
  {
    "SourceLocation": "England",
    "DestinationLocation": "Netherlands",
    "DeliveryDate": "12/12"
  }
]

Desired result:

[
 {
    "SourceLocation": "England",
    "DestinationLocation": "Netherlands",
    "DeliveryDate": "12/12"
  }
]

CodePudding user response：

You could convert the string representation of Json to JArrays (I see you have list of items) and compare each item. For example (inline comments included for code),


 public IEnumerable<String> CompareJsonArrays(string expected,string actual)
 {
    // Parse string to JArrays
    JArray firstArray = JArray.Parse(expected);
    JArray secondArray = JArray.Parse(actual);
    
    // retrieve all children of JArray
    var firstTokens = firstArray.Children();
    var secondTokens = secondArray.Children();
    
    // Compare the two set of collections using Custom comparer
    var results = firstTokens.Except(secondTokens, new JTokenComparer())
                .Concat(secondTokens.Except(firstTokens,new JTokenComparer()));
    
    // Convert to Json String Representation
    return results.Select(x=>x.ToString());

 }

Where JTokenComparer is defined as

public class JTokenComparer : IEqualityComparer<JToken>
{
    public int GetHashCode(JToken co)
    {
        return 1;
    }

    public bool Equals(JToken x1, JToken x2)
    {
        if (object.ReferenceEquals(x1, x2))
        {
            return true;
        }
        if (object.ReferenceEquals(x1, null) ||
            object.ReferenceEquals(x2, null))
        {
            return false;
        }
        // Compares token and all child tokens.
        return JToken.DeepEquals(x1,x2);
    }
}

Now you could compare the two json strings as following

CompareJsonArrays(json1,json2);

The Custom Comparer uses JToken.DeepEquals() for retrieving difference between tokens.