add HEAD request support and return response headers for all request types both for success and failures.

src/android/com/synconset/CordovaHTTP/CordovaHttp.java

@@ -12,6 +12,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.BufferedReader;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -109,4 +111,17 @@ public abstract class CordovaHttp {
     protected void respondWithError(String msg) {
         this.respondWithError(500, msg);
     }
+
+    protected void addResponseHeaders(HttpRequest request, JSONObject response) throws JSONException {
+        Map<String, List<String>> headers = request.headers();
+        Map<String, String> parsed_headers = new HashMap<String, String>();
+        for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
+            String key = entry.getKey();
+            List<String> value = entry.getValue();
+            if ((key != null) && (!value.isEmpty())) {
+                parsed_headers.put(key, value.get(0));
+            }
+        }
+        response.put("headers", new JSONObject(parsed_headers));
+    }
 }

src/android/com/synconset/CordovaHTTP/CordovaHttpDownload.java

@@ -40,6 +40,7 @@ public class CordovaHttpDownload extends CordovaHttp implements Runnable {
             int code = request.code();
             
             JSONObject response = new JSONObject();
+            this.addResponseHeaders(request, response);
             response.put("status", code);
             if (code >= 200 && code < 300) {
                 URI uri = new URI(filePath);

src/android/com/synconset/CordovaHTTP/CordovaHttpGet.java

@@ -40,6 +40,7 @@ public class CordovaHttpGet extends CordovaHttp implements Runnable {
             int code = request.code();
             String body = request.body(CHARSET);
             JSONObject response = new JSONObject();
+            this.addResponseHeaders(request, response);
             response.put("status", code);
             if (code >= 200 && code < 300) {
                 response.put("data", body);

src/android/com/synconset/CordovaHTTP/CordovaHttpHead.java

@@ -0,0 +1,64 @@
+/**
+ * A HTTP plugin for Cordova / Phonegap
+ */
+package com.synconset;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.UnknownHostException;
+import java.util.Map;
+
+import javax.net.ssl.HttpsURLConnection;
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.HostnameVerifier;
+
+import javax.net.ssl.SSLHandshakeException;
+
+import org.apache.cordova.CallbackContext;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import android.util.Log;
+
+import com.github.kevinsawicki.http.HttpRequest;
+import com.github.kevinsawicki.http.HttpRequest.HttpRequestException;
+ 
+public class CordovaHttpHead extends CordovaHttp implements Runnable {
+    public CordovaHttpHead(String urlString, Map<?, ?> params, Map<String, String> headers, CallbackContext callbackContext) {
+        super(urlString, params, headers, callbackContext);
+    }
+    
+    @Override
+    public void run() {
+        try {
+            HttpRequest request = HttpRequest.head(this.getUrlString(), this.getParams(), true);
+            this.setupSecurity(request);
+            request.acceptCharset(CHARSET);
+            request.headers(this.getHeaders());
+            int code = request.code();
+            JSONObject response = new JSONObject();
+            this.addResponseHeaders(request, response);
+            response.put("status", code);
+            if (code >= 200 && code < 300) {
+                // no 'body' to return for HEAD request
+                this.getCallbackContext().success(response);
+            } else {
+                String body = request.body(CHARSET);
+                response.put("error", body);
+                this.getCallbackContext().error(response);
+            }
+        } catch (JSONException e) {
+            this.respondWithError("There was an error generating the response");
+        } catch (HttpRequestException e) {
+            if (e.getCause() instanceof UnknownHostException) {
+                this.respondWithError(0, "The host could not be resolved");
+            } else if (e.getCause() instanceof SSLHandshakeException) {
+                this.respondWithError("SSL handshake failed");
+            } else {
+                this.respondWithError("There was an error with the request");
+            }
+        }
+    }
+}

src/android/com/synconset/CordovaHTTP/CordovaHttpPlugin.java

@@ -58,6 +58,14 @@ public class CordovaHttpPlugin extends CordovaPlugin {
             HashMap<String, String> headersMap = this.addToMap(this.globalHeaders, headers);
             CordovaHttpGet get = new CordovaHttpGet(urlString, paramsMap, headersMap, callbackContext);
             cordova.getThreadPool().execute(get);
+        } else if (action.equals("head")) {
+            String urlString = args.getString(0);
+            JSONObject params = args.getJSONObject(1);
+            JSONObject headers = args.getJSONObject(2);
+            HashMap<?, ?> paramsMap = this.getMapFromJSONObject(params);
+            HashMap<String, String> headersMap = this.addToMap(this.globalHeaders, headers);
+            CordovaHttpHead head = new CordovaHttpHead(urlString, paramsMap, headersMap, callbackContext);
+            cordova.getThreadPool().execute(head);
         } else if (action.equals("post")) {
             String urlString = args.getString(0);
             JSONObject params = args.getJSONObject(1);

src/android/com/synconset/CordovaHTTP/CordovaHttpPost.java

@@ -33,6 +33,7 @@ public class CordovaHttpPost extends CordovaHttp implements Runnable {
             int code = request.code();
             String body = request.body(CHARSET);
             JSONObject response = new JSONObject();
+            this.addResponseHeaders(request, response);
             response.put("status", code);
             if (code >= 200 && code < 300) {
                 response.put("data", body);

src/android/com/synconset/CordovaHTTP/CordovaHttpUpload.java

@@ -70,6 +70,7 @@ public class CordovaHttpUpload extends CordovaHttp implements Runnable {
             String body = request.body(CHARSET);
             
             JSONObject response = new JSONObject();
+            this.addResponseHeaders(request, response);
             response.put("status", code);
             if (code >= 200 && code < 300) {
                 response.put("data", body);