1 files changed, 171 insertions, 0 deletions
diff --git a/wso2bpel-ext/wso2bpel-core/BPEL4RESTLight/src/main/java/org/opentosca/bpel4restlight/rest/LowLevelRestApi.java b/wso2bpel-ext/wso2bpel-core/BPEL4RESTLight/src/main/java/org/opentosca/bpel4restlight/rest/LowLevelRestApi.java
new file mode 100644
index 0000000..2c6bc94
--- /dev/null
+++ b/wso2bpel-ext/wso2bpel-core/BPEL4RESTLight/src/main/java/org/opentosca/bpel4restlight/rest/LowLevelRestApi.java
@@ -0,0 +1,171 @@
+/**
+ * This static-class eases HTTP-method execution by self-managed fault-handling
+ * and automated Response-information processing
+ */
+package org.opentosca.bpel4restlight.rest;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.httpclient.Header;
+import org.apache.commons.httpclient.HttpClient;
+import org.apache.commons.httpclient.HttpMethod;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.json.simple.JSONArray;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+
+
+public class LowLevelRestApi {
+	
+  protected static final Log log = LogFactory.getLog(LowLevelRestApi.class);
+	// Local HttpClient used for every communication (Singleton implementation)
+//	private static HttpClient httpClient = new HttpClient();
+	
+	/**
+	 * Executes a passed HttpMethod (Method type is either PUT, POST, GET or
+	 * DELETE) and returns a HttpResponseMessage
+	 * 
+	 * @param method Method to execute
+	 * @return HttpResponseMessage which contains all information about the
+	 *         execution
+	 */
+	public static HttpResponseMessage executeHttpMethod(HttpMethod method) {
+		
+		HttpResponseMessage responseMessage = null;
+		
+		try {
+			log.debug("Method invocation on URI: \n");
+			log.debug(method.getURI().toString());
+			
+			// Execute Request
+			HttpClient httpClient = new HttpClient();
+			httpClient.executeMethod(method);
+			responseMessage = LowLevelRestApi.extractResponseInformation(method);
+			
+		} catch (Exception e) {
+		  log.error("call rest error:", e);
+		} finally {
+			// Release Connection anyway
+			method.releaseConnection();
+		}
+		
+		// Extract response information and return
+		return responseMessage;
+	}
+	
+	/**
+	 * Extracts the response information from an executed HttpMethod
+	 * 
+	 * @param method Executed Method
+	 * @return Packaged response information
+	 */
+	private static HttpResponseMessage extractResponseInformation(HttpMethod method) {
+		// Create and return HttpResponseMethod
+		HttpResponseMessage responseMessage = new HttpResponseMessage();
+		responseMessage.setStatusCode(method.getStatusCode());
+		try {
+			responseMessage.setResponseBody(getResponseBody(method));
+		} catch (Exception e) {
+		    log.error(e);
+		}
+		return responseMessage;
+		
+	}
+	
+	/**
+	 * getResponseBody 
+	 * 
+	 * get response body info, if response body is a json object, then translate json object to xml
+	 * if the rest request failed, i.e. the response body is a 404 error page, then response the body with header <root>
+	 * @param method
+	 * @return
+	 * @throws ParseException
+	 */
+	private static String getResponseBody(HttpMethod method) throws ParseException
+	{
+	  String result = null;
+	  try {
+	    result = method.getResponseBodyAsString();
+		log.debug("result:");
+		log.debug(result);
+	  } catch (IOException e) {
+	    log.error(e);
+	  }
+	  
+	  Header header = method.getRequestHeader("Accept");
+	  if ("application/json".equals(header.getValue())) {
+	    StringBuilder sb = new StringBuilder();
+	    sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+	    sb.append("<root>");
+	    if(result != null && !"".equals(result)) {
+	      /**
+		  if(result.startsWith("<html>")) {
+	        sb.append("<![CDATA[");
+	        sb.append(result);
+	        sb.append("]]>");
+	      } else {
+	        Object json = new JSONParser().parse(result);
+	        json2Xml(sb, "obj", json);
+	      }
+		  */
+		  
+		  try {
+			Object json = new JSONParser().parse(result);
+	        json2Xml(sb, "obj", json);
+		  } catch (Exception e) {
+			log.error(e);
+			sb.append("<![CDATA[");
+	        sb.append(result);
+	        sb.append("]]>");
+		  }
+	    }
+	    sb.append("</root>");
+	    
+		log.debug("responseBody:");
+		log.debug(sb.toString());
+	    return sb.toString();
+	  }
+	  return result;
+	}
+	
+	
+	@SuppressWarnings("unchecked")
+	public static void json2Xml(StringBuilder sb, String key,  Object jsonObject) {
+	  if(jsonObject == null) {
+	    sb.append("<error>empty</error>");
+	    return;
+	  }
+	  
+	  if(jsonObject instanceof JSONArray) {
+	    JSONArray array = (JSONArray) jsonObject;
+	    sb.append("<").append(key).append("s").append(">");
+	    for(int i=0, len=array.size(); i<len; i++) {
+	      json2Xml(sb, key, array.get(i));
+	    }
+	    sb.append("</").append(key).append("s").append(">");
+	    
+	    return;
+	  } else if(jsonObject instanceof JSONObject) {
+	    sb.append("<").append(key).append(">");
+	    JSONObject json = (JSONObject) jsonObject;
+	    for(Map.Entry<String, Object> entry : (Set<Map.Entry<String, Object>>)json.entrySet()) {
+	      json2Xml(sb, entry.getKey(), entry.getValue());
+	    }
+	    sb.append("</").append(key).append(">");
+	    return;
+	  } else {
+	    sb.append("<").append(key).append(">");
+	    sb.append("<![CDATA[");
+	    sb.append(jsonObject.toString());
+	    sb.append("]]>");
+	    sb.append("</").append(key).append(">");
+	    
+	    return;
+	  }
+	}
+	
+}