HttpConnector

ApexExtension.cls

public inherited sharing virtual class ApexExtension {

    public static String str(String input){
        return input == null ? '' : input;
    }

    public static String str(Object input){
        return str(String.valueOf(input));
    }

    public static String str(String input, String defaultValue){
        return String.isBlank(str(input)) ? defaultValue : input;
    }

    public static Object obj( Object element, Object defaultValue ){
        return element == null ? defaultValue : element;
    }

    public static Object def( Object element, Object defaultValue ){
        return element == null ? defaultValue : element;
    }

    public static Boolean bool(Boolean input,Boolean defaultValue ){
        return (Boolean) obj(input,defaultValue);
    }

    public static Decimal dec(Decimal input,Decimal defaultValue ){
        return (Decimal) obj(input,defaultValue);
    }

    public static Integer int(Object input,Integer defaultValue ){
        return Integer.valueOf(obj(input,defaultValue));
    }

    public static List<String> lst(){
        return new List<String>();
    }

    public static List<Object> lst( List<Object> elements ){
        return (List<Object>) obj(elements, new List<Object>());
    }

    public static List<String> lst(Object lstObject){
        return lstObject == null ? lst() : (List<String>) lstObject;
    }

    public static List<String> lst( List<String> elements ){
        return (List<String>) obj(elements, lst());
    }

    public static List<String> lst(Set<String> elements){
        return new List<String>(elements);
    }

    public static List<String> lst(String index0,String index1){
        return new List<String>{index0,index1};
    }

    public static List<String> lst(String index0,String index1,String index2){
        return new List<String>{index0,index1,index2};
    }

    public static Set<String> set(String index0,String index1){
        return new Set<String>{index0,index1};
    }
}

HttpConnector.cls

public inherited sharing class HttpConnector extends ApexExtension {

    public static final String METHOD_POST = 'POST';
    public static final String METHOD_GET = 'GET';

    private Http http;
    private HttpRequest request;
    private HttpResponse response;

    private Map<String,String> paramsMap;
    private String             endPointURL;

    public HttpConnector() {
        http = new Http();
        request = new HttpRequest();
        paramsMap = new Map<String,String>();
    }

    public HttpConnector setEndPoint(String endPoint){
        this.endPointURL = endPoint;
        return this;
    }

    public HttpConnector setMethod(String method){
        this.request.setMethod(method);
        return this;
    }

    public HttpConnector setHeader(String key,String value){
        this.request.setHeader(key, value);
        return this;
    }

    public HttpConnector setHeader(Map<String,String> header){

        for(String key : header.keySet() ){
            this.request.setHeader( key , header.get(key) );
        }
        
        return this;
    }

    public HttpConnector setParam(String key,String value) {
        paramsMap.put(key, value);
        return this;
    }

	public HttpConnector setBody(String body){
        this.request.setBody(body);
        return this;
    }
    public SyncResponse send(){
        String errorMessage, statusCode;
        SyncResponse syncResponse = new SyncResponse();

        request.setEndpoint( getURL() );

        this.response = http.send(request);

        try{
            String responseBody = str( this.response.getBody() ).trim();
            Boolean isJSON      = responseBody.startsWith('{');
            Boolean isArray     = responseBody.startsWith('[');

            if( isArray ) {
                syncResponse.resultList  = (List<Object>) JSON.deserializeUntyped(responseBody);
            } else if( isJSON ) {
                syncResponse.result = (Map<String,Object>)JSON.deserializeUntyped(responseBody);
            }
        } catch(Exception exp){
            syncResponse.error  = exp.getMessage();
        }

        statusCode = ''+response.getStatusCode();

        //not success ?
        if( !statusCode.startsWith('2')  ){
            syncResponse.error  = response.getStatus();
            syncResponse.isSuccess = false;
        } else {
            syncResponse.error = '';
            syncResponse.isSuccess = true;
        }

        syncResponse.statusCode             = statusCode;
        syncResponse.status                 = response.getStatus();
        syncResponse.responseBody           = response.getBody();

        return syncResponse;
    }

    public HttpResponse getResponse(){
        return this.response;
    }

    public HttpRequest getRequest(){
        return this.request;
    }

    public String getURL(){
        endPointURL =  str( endPointURL );
        Boolean isFirst=true;
        String prefix,value;
        
        for(String key : paramsMap.keySet()){
            prefix = isFirst ? '?' : '&';
            value  = EncodingUtil.urlEncode(paramsMap.get(key), 'UTF-8');
            endPointURL += ( prefix + key + '=' + value );
            isFirst = false;
        }
        
        return endPointURL;
    }
	
	
}

SyncResponse.cls

public inherited sharing class SyncResponse {
    public SyncResponse() {
        isSuccess = false;
    }
    
    public Map<String,Object> result     {set;get;}
    public List<Object> resultList       {set;get;}
    public Boolean isSuccess             {set;get;}
    public String error                  {set;get;}
    public String statusCode             {set;get;}
    public String status                 {set;get;}
    public String responseBody           {set;get;}

}