added support for empty query parameters

codec-http/src/main/java/io/netty/handler/codec/http/QueryStringEncoder.java

@@ -72,9 +72,6 @@ public class QueryStringEncoder {
         if (name == null) {
             throw new NullPointerException("name");
         }
-        if (value == null) {
-            throw new NullPointerException("value");
-        }
         params.add(new Param(name, value));
     }
 
@@ -101,8 +98,10 @@ public class QueryStringEncoder {
             for (int i = 0; i < params.size(); i++) {
                 Param param = params.get(i);
                 sb.append(encodeComponent(param.name, charset));
+                if (param.value != null) {
                     sb.append('=');
                     sb.append(encodeComponent(param.value, charset));
+                }
                 if (i != params.size() - 1) {
                     sb.append('&');
                 }

codec-http/src/test/java/io/netty/handler/codec/http/QueryStringEncoderTest.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2014 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.handler.codec.http;
+
+import java.net.URI;
+import java.nio.charset.Charset;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class QueryStringEncoderTest {
+
+    @Test
+    public void testDefaultEncoding() throws Exception {
+        QueryStringEncoder e;
+
+        e = new QueryStringEncoder("/foo");
+        e.addParam("a", "b=c");
+        Assert.assertEquals("/foo?a=b%3Dc", e.toString());
+        Assert.assertEquals(new URI("/foo?a=b%3Dc"), e.toUri());
+
+        e = new QueryStringEncoder("/foo/\u00A5");
+        e.addParam("a", "\u00A5");
+        Assert.assertEquals("/foo/\u00A5?a=%C2%A5", e.toString());
+        Assert.assertEquals(new URI("/foo/\u00A5?a=%C2%A5"), e.toUri());
+
+        e = new QueryStringEncoder("/foo");
+        e.addParam("a", "1");
+        e.addParam("b", "2");
+        Assert.assertEquals("/foo?a=1&b=2", e.toString());
+        Assert.assertEquals(new URI("/foo?a=1&b=2"), e.toUri());
+
+        e = new QueryStringEncoder("/foo");
+        e.addParam("a", "1");
+        e.addParam("b", "");
+        e.addParam("c", null);
+        e.addParam("d", null);
+        Assert.assertEquals("/foo?a=1&b=&c&d", e.toString());
+        Assert.assertEquals(new URI("/foo?a=1&b=&c&d"), e.toUri());
+    }
+
+    @Test
+    public void testNonDefaultEncoding() throws Exception {
+        QueryStringEncoder e = new QueryStringEncoder("/foo/\u00A5", Charset.forName("UTF-16"));
+        e.addParam("a", "\u00A5");
+        Assert.assertEquals("/foo/\u00A5?a=%FE%FF%00%A5", e.toString());
+        Assert.assertEquals(new URI("/foo/\u00A5?a=%FE%FF%00%A5"), e.toUri());
+    }
+}