Salesforce Apex Code for Using Token Based Authentication to call NetSuite RESTlets

NetSuiteTBAWS.cls

@RestResource(urlMapping='/Netsuite/TBA/*')
global with sharing class NetSuiteTBATestWS {
    
    @HttpGet
    global static String doGet() {

		OAuth10a oAuth = new OAuth10a();
		Http h = new Http();
		HttpRequest req = new HttpRequest();
		req.setMethod('GET');
		req.setEndpoint('<RESTletURL>');
		
        String header = oAuth.sign(req);
        req.setHeader('Authorization', header);
        System.debug('Request body set to: '+req.getBody());

        HttpResponse res = new HttpResponse();
        res = h.send(req);

        return res.getStatusCode() + ' Body = '+res.getBody();
    }
}

OAuth10a.cls

public with sharing class OAuth10a {
    private String token = '<token>';
    private String tokenSecret = '<tokenSecret>';
    private String netSuiteAccountId = '<accountId>';
    private String oAuthVersion = '1.0';
    private Boolean isAccess = false;
    private String verifier;

    private String nonce;
    private String timestamp;
    private String signature;
    private String consumerKey = '<consumerKey>';
    private String consumerSecret = '<consumerSecret>';

    private Map<String,String> parameters = new Map<String,String>();
 
 	public String message { get; set; }
 	public String callbackUrl {get; set; }

 	public void setConsumerKey(String value) { consumerKey = value; }
	public void setConsumerSecret(String value) { consumerSecret = value; }   

	private void refreshParameters() {
		parameters.clear();
		parameters.put('oauth_consumer_key',consumerKey);
		parameters.put('oauth_nonce',nonce);
		if(token!=null) {
			parameters.put('oauth_token',token);
		}
		if(verifier!=null) {
			parameters.put('oauth_verifier',verifier);
		}
		parameters.put('oauth_signature_method','HMAC-SHA1');
		parameters.put('oauth_timestamp',timestamp);
		//parameters.put('oauth_version', oAuthVersion);
		// parameters.put('oauth_callback',callbackUrl);
	}
	
	private Map<String,String> getUrlParams(String value) {
		Map<String,String> res = new Map<String,String>();
		if(value==null || value=='') {
			return res;
		}
		for(String s : value.split('&')) {
			System.debug('getUrlParams: '+s);
			List<String> kv = s.split('=');
			if(kv.size()>1) {
			  // RFC 5849 section 3.4.1.3.1 and 3.4.1.3.2 specify that parameter names 
			  // and values are decoded then encoded before being sorted and concatenated
			  // Section 3.6 specifies that space must be encoded as %20 and not +
			  String encName = EncodingUtil.urlEncode(EncodingUtil.urlDecode(kv[0], 'UTF-8'), 'UTF-8').replace('+','%20');
			  String encValue = EncodingUtil.urlEncode(EncodingUtil.urlDecode(kv[1], 'UTF-8'), 'UTF-8').replace('+','%20');
			  System.debug('getUrlParams:  -> '+encName+','+encValue);
			  res.put(encName,encValue);
			}
		}
		return res;
	}

	private String createBaseString(Map<String,String> oauthParams, HttpRequest req) {
		Map<String,String> p = oauthParams.clone();
		if(req.getMethod().equalsIgnoreCase('post') && req.getBody()!=null && 
		   req.getHeader('Content-Type')=='application/x-www-form-urlencoded') {
		   	p.putAll(getUrlParams(req.getBody()));
		}
		String host = req.getEndpoint();
		Integer n = host.indexOf('?');
		if(n>-1) {
			p.putAll(getUrlParams(host.substring(n+1)));
			host = host.substring(0,n);
		}
		List<String> keys = new List<String>();
		keys.addAll(p.keySet());
		keys.sort();
		String s = keys.get(0)+'='+p.get(keys.get(0));
		for(Integer i=1;i<keys.size();i++) {
			s = s + '&' + keys.get(i)+'='+p.get(keys.get(i));
		}

		// According to OAuth spec, host string should be lowercased, but Google and LinkedIn
		// both expect that case is preserved.
		return req.getMethod().toUpperCase()+ '&' + 
			EncodingUtil.urlEncode(host, 'UTF-8') + '&' +
			EncodingUtil.urlEncode(s, 'UTF-8');
	}

	public String sign(HttpRequest req) {
		nonce = String.valueOf(Crypto.getRandomLong());
		timestamp = String.valueOf(DateTime.now().getTime()/1000);

		refreshParameters();
		
		String s = createBaseString(parameters, req);
		
		System.debug('Signature base string: '+s);
		
		Blob sig = Crypto.generateMac('HmacSHA1', Blob.valueOf(s), 
				       Blob.valueOf(consumerSecret+'&'+
				       	            (tokenSecret!=null ? tokenSecret : '')));
		signature = EncodingUtil.urlEncode(EncodingUtil.base64encode(sig), 'UTF-8');
		System.debug('Signature: '+signature);
		
		String header = 'OAuth ';
		for (String key : parameters.keySet()) {
			header = header + key + '="'+parameters.get(key)+'", ';
		}
		header = header + 'oauth_signature="'+signature+'"'+',realm="'+netSuiteAccountId+'"';
		System.debug('Authorization: '+header);
		req.setHeader('Authorization',header);
		req.setHeader('Content-Type', 'application/json');

		return header;
	}
}

Hi,

Need you help for integrating Salesforce with NetSuite. Could you please reply back to this comment. Thanks in advance.