[SalesForce] REST API calls from salesforce and parse the JSON to display on the vf page

I have to make REST API call from salesforce to a HTTP URL GET method to get the JSON response parse it and display it on the vf page.

My Questions:

From the class below how can I check the status code of the response?
How to map the returned response to the Parser class which I generated from JSON2APEX using the sample JSON?
How to do the mappings on the returned JSON to the account and corporation objects in salesforce?
Can I display the info on vf page without saving or mapping to the corresponding objects in salesforce?

Integration Class:

public class MySQLIntegrationHelper{
public String getResult{get;set;}
//public String Response {get; set;}

public PageReference submit() {
    getResult=getData();
    return null;
}

public String getData()
{
    HttpRequest req= new HttpRequest();
    Http http = new Http();
    req.setMethod('GET');
    String url = 'http://mysql.com/buyout/account/1234';
    req.setEndpoint(url);
    String username = 'test';
    String password = 'testpw';
    Blob headerValue = Blob.valueOf(username + ':' + password);
    String authorizationHeader = 'BASIC ';
    System.debug( 'authorizationHeader : ' + authorizationHeader );
    req.setHeader('Authorization', authorizationHeader);
    }
    try {
        HttpResponse res = new Http.send(req);
        System.debug(res.toString());
        System.debug('STATUS:'+res.getStatus());
        System.debug('STATUS_CODE:'+res.getStatusCode());

    } catch (System.CalloutException e) {
       System.debug('The callout failed with this message:'+e); 
    } 
    return null;  
}

JSON Parser:

public class MySQLJSONParser {

public class Corporations {
    public Integer id;
    public String listingid;
    public String corporation_id;
    public String location_id;
    public String title;
}

public Account Account;
public List<Corporations> Corporations;

public class Account {
    public Integer id;
    public String InternalAccountId;
    public String account_id;
    public String name;
    public String status;
    public String bid_type;
}


public static MySQLJSONParser parse(String json) {
    return (MySQLJSONParser) System.JSON.deserialize(json, MySQLJSONParser.class);
}

Best Answer

Here is an outline for 1/2/3 assuming you want to insert the data. If it's an update you'll need to query the existing versions of the objects:

HTTPResponse res = new Http().send(req);
if (res.getStatusCode() == 200) {
    Corporation__c corps = new Corporation__c[] {};
    MySQLJSONParser p = MySQLJSONParser.parse(res.getBody());
    for (MySQLJSONParser.Corporation c : p.Corporations) {
        corps.add(new Corporation__c(
                Title__c = c.title,
                ...
                ));
    }
    insert corps;
} else {
    throw new MyException('HTTP callout failed:'
            + '\nendPoint=' + req.getEndPoint()
            + '\nstatusCode=' + res.getStatusCode()
            + '\nstatus=' + res.getStatus()
            + '\nbody=' + res.getBody()
            );
}

On 4, yes you can present objects returned by the parse directly in your page if you want to: Visualforce can present Apex object data but you have to do more work such as outputting your own labels.

Related Solutions

[SalesForce] How to get Json response without rest api and parse the response in objects

I'm not sure I understand your question. By "without calling out" and "can get response from other callback url" do you mean that you want to publish an endpoint that will accept JSON that is posted to it? If so you can create an @RestResource Apex class with a @HttpPost method that can hanle most of the work - including deserialization from a JSON String to Apex objects - for you.

But if you have the JSON string available and are just asking how to parse it, there are lots of tools to help you parse it into Apex objects. In the JSON class:

JSON.deserializeStrict(String jsonString, System.Type apexType)
JSON.deserialize(String jsonString, System.Type apexType)
JSON.deserializeUntyped(String jsonString)
JSON.createParser(String jsonString)

Which of these JSON methods you choose depends on how fixed (known up front) the format of the JSON is. I've listed the methods in order of "best for fixed" though to "best for not fixed".

From your comments below it sounds like you want to setup a REST endpoint in Salesforce that your "call centre website" can invoke. (The process will have to include authentication.) A @RestResource Apex class works well for this and would look something like this:

@RestResource(urlMapping='/myName')
global with sharing class MyRest {

    @HttpPost
    global static String doPost(...) {
        // Apex code that does something with the posted data
    }
}

where ... is up to you: zero or more primitive values, simple Apex classes, SObjects, arrays of any of these. The framework automatically deserializes the JSON based on the parameter list.

To provide an example, this JSON:

{"abc": "some message", "def": [1, 2, 3]}

would be automatically deserialized by this code:

@HttpPost
global static String doPost(String abc, Integer[] def) {
    // abc will be "some message"
    // def will be the Integer array 1, 2, 3 
}

You mention "it should be dynamic" but I am not sure what you mean by that.

[SalesForce] Parse JSON Response and add to Visualforce Page

Using JSON2Apex (here), you can easily generate a class that you can use to deserialize your JSON.

JSON2Apex outputs code like this:

    public class Outer {

    public List<Ideal> ideal;
    public List<Ideal> idealFiltered;
    public List<Ideal> InBudget;

    public class Ideal {
        public String product;
        public String percent;
        public String dollarAmount;
    }

    public static Outer parse(String json) {
        return (Outer) System.JSON.deserialize(json, Outer.class);
    }
}

From here, you can iterate through the lists inside the main Object and extract the values as you need.

The key is the parse method. What you need to do is pass in your string like this:

Outer myParsedResult = Outer.parse(httpCalloutResponseString);

Then you can literally go:

for (Ideal idealItem : Outer.ideal){
    //do something here... maybe if a value is x, assign that value to your 
    //public property on your vf page etc...
}

Best Answer

Related Solutions

[SalesForce] How to get Json response without rest api and parse the response in objects

[SalesForce] Parse JSON Response and add to Visualforce Page

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