Salesforce SQS.java

public class AmazonSqsSender
{

	private String getCurrentDate() {
		return DateTime.now().formatGmt('yyyy-MM-dd\'T\'HH:mm:ss.SSS\'Z\'');
	}

	public void sendMessage(String message) {
		//AmazonAws__c is a custom setting object that stores our keys, an Amazon Host, and a queue name
		//You can just put your keys, host and queue below as strings
		AmazonAws__c aws = AmazonAws__c.getOrgDefaults();

		String accessKey =aws.accessKey__c;
		String secretKey = aws.secretKey__c;
		String host = aws.host__c;
		String queue = aws.queue__c;

		Map<String,String> params = new Map<String,String>();

		params.put('AWSAccessKeyId',encode(accessKey));
		params.put('Action','SendMessage');
		params.put('MessageBody',encode(message));
		params.put('Timestamp',encode(getCurrentDate()));
		params.put('SignatureMethod','HmacSHA1');
		params.put('SignatureVersion','2');
		params.put('Version','2009-02-01');

		//The string to sign has to be sorted by keys
		List<String> sortedKeys = new List<String>();
		sortedKeys.addAll(params.keySet());
		sortedKeys.sort();

		String toSign = 'GET\n' + host +'\n'+queue+'\n';
		Integer p = 0;
		for (String key : sortedKeys) {
			String value = params.get(key);
			if (p > 0) {
				toSign += '&';
			}
			p++;
			toSign += key+'='+value;
		}
		params.put('Signature',getMac(toSign,secretKey));

		String url = 'https://'+ host+queue+'?';
		p = 0;
		for (String key : params.keySet()) {
			if (p > 0) {
				url += '&';
			}
			p++;
			url += key+'='+params.get(key);
		}

		HttpRequest req = new HttpRequest();
		req.setEndPoint(url);
		req.setMethod('GET');
		Http http = new Http();
		try {
			//System.debug('Signed string: ' + toSign);
			//System.debug('Url: ' + url);
			HttpResponse res = http.send(req);
			//System.debug('Status: ' + res.getStatus());
			//System.debug('Code  : ' + res.getStatusCode());
			//System.debug('Body  : ' + res.getBody());
		}
		catch (System.CalloutException e) {
			System.debug('ERROR: ' + e);
		}

	}
//Amazon wants + and * to be escaped, but not ~
	private String encode(String message){
		return EncodingUtil.urlEncode(message,'UTF-8').replace('+', '%20').replace('*', '%2A').replace('%7E','~');
	}

	private String getMac(String RequestString, String secretkey) {
		String algorithmName = 'hmacSHA1';
		Blob input = Blob.valueOf(RequestString);
		Blob key = Blob.valueOf(secretkey);
		Blob signing =Crypto.generateMac(algorithmName, input, key);
		return EncodingUtil.urlEncode(EncodingUtil.base64Encode(signing), 'UTF-8');
	}

	public static void sendTest() {
		AmazonSqsSender t = new AmazonSqsSender();
		t.sendMessage('Hello from Salesforce ' + Math.random());
	}
}