Add additional utils

Author: mythz

src/AndroidClient/client/src/main/java/net/servicestack/client/Utils.java

@@ -21,15 +21,20 @@
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.net.HttpURLConnection;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLEncoder;
 import java.nio.ByteBuffer;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.UUID;
 
 import static net.servicestack.func.Func.last;
@@ -394,6 +399,21 @@ else if (parts.length == 2)
     }
 
     /*String Utils*/
+    public static boolean isEmpty(final String string)
+    {
+        return string == null || string.length() == 0;
+    }
+
+    public static boolean isNullOrEmpty(final String string)
+    {
+        return string == null || string.length() == 0;
+    }
+
+    public static boolean isNullOrWhiteSpace(final String string)
+    {
+        return string == null || string.length() == 0 || string.trim().length() == 0;
+    }
+
     public static String[] splitOnFirst(String strVal, char needle) {
         return splitOnFirst(strVal, needle, 0);
     }
@@ -475,6 +495,16 @@ public static byte[] toUtf8Bytes(String string) {
         }
     }
 
+    public static String readToEnd(String url) {
+        try {
+            URL heartbeatUrl = new URL(url);
+            HttpURLConnection conn = (HttpURLConnection)heartbeatUrl.openConnection();
+            return readToEnd(conn);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     public static String readToEnd(HttpURLConnection response){
         try {
             return readToEnd(response.getInputStream(), "UTF-8");
@@ -786,4 +816,71 @@ private static byte[] encode3to4(
         }
     }
 
+    public static String addQueryParam(String url, String key, String value) {
+        return addQueryParam(url, key, value, true);
+    }
+
+    public static String addQueryParam(String url, String key, String val, boolean encode) {
+        if (url == null || url.length() == 0)
+            return null;
+        String prefix = "";
+        if (!url.endsWith("?") && !url.endsWith("&")) {
+            prefix = url.indexOf('?') == -1 ? "?" : "&";
+        }
+        try {
+            return url + prefix + key + "=" + (encode && val != null ? URLEncoder.encode(val, "UTF-8") : val);
+        } catch (UnsupportedEncodingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static final String EMPTY = "";
+
+    public static String toString(Object o, String nullDefault) {
+        return (o != null) ? o.toString() : nullDefault;
+    }
+
+    public static String join(final String[] array, final String separator) {
+        if (array == null)
+            return null;
+
+        return join(Arrays.asList(array), separator);
+    }
+
+    public static String join(final Iterable<?> iterable, final String separator) {
+        if (iterable == null) {
+            return null;
+        }
+        return join(iterable.iterator(), separator);
+    }
+
+    public static String join(final Iterator<?> iterator, final String separator) {
+        if (iterator == null) {
+            return null;
+        }
+        if (!iterator.hasNext()) {
+            return EMPTY;
+        }
+        final Object first = iterator.next();
+        if (!iterator.hasNext()) {
+            final String result = toString(first, "");
+            return result;
+        }
+
+        final StringBuilder buf = new StringBuilder(256);
+        if (first != null) {
+            buf.append(first);
+        }
+
+        while (iterator.hasNext()) {
+            if (separator != null) {
+                buf.append(separator);
+            }
+            final Object obj = iterator.next();
+            if (obj != null) {
+                buf.append(obj);
+            }
+        }
+        return buf.toString();
+    }
 }