Support multiple duplicate queryparams (#134)

The SendGrid API documentation states that the user can supply up to ten
categories, but there is no way to supply them using the Java library.

This commit fixes the problem by interpreting any value that has an
ampersand in it as a list of values, which will be inserted as multiple
query params.

For example, the call request.addQueryParam("categories", "cat1&cat2")
will output "?categories=cat1&categories=cat2" into the URL.

Author: mjjs

Diff for: README.md

@@ -100,6 +100,8 @@ try {
 request.addHeader("Authorization", "Bearer YOUR_API_KEY");
 request.addQueryParam("limit", "100");
 request.addQueryParam("offset", "0");
+// Will be parsed to categories=cake&categories=pie&categories=baking
+request.addQueryParam("categories", "cake&pie&baking");
 request.setBody("{\"name\": \"My Request Body\"}");
 request.setMethod(Method.POST);
 String param = "param";

Diff for: src/main/java/com/sendgrid/Client.java

@@ -9,6 +9,8 @@
 import java.nio.charset.Charset;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Arrays;
+import java.util.List;
 
 import org.apache.http.Header;
 import org.apache.http.HttpMessage;
@@ -129,8 +131,19 @@ public URI buildUri(String baseUri, String endpoint, Map<String, String> queryPa
 		builder.setPath(endpoint);
 
 		if (queryParams != null) {
+			String multiValueDelimiter = "&";
+
 			for (Map.Entry<String, String> entry : queryParams.entrySet()) {
-				builder.setParameter(entry.getKey(), entry.getValue());
+				String value = entry.getValue();
+
+				if (value.indexOf(multiValueDelimiter) != -1) {
+					List<String> values = Arrays.asList(value.split(multiValueDelimiter));
+					for (String val : values) {
+						builder.addParameter(entry.getKey(), val);
+					}
+				} else {
+					builder.setParameter(entry.getKey(), entry.getValue());
+				}
 			}
 		}
 

Diff for: src/test/java/com/sendgrid/ClientTest.java

@@ -33,8 +33,10 @@
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -62,6 +64,7 @@ public void testbuildUri() {
     Map<String,String> queryParams = new HashMap<String,String>();
     queryParams.put("test1", "1");
     queryParams.put("test2", "2");
+    queryParams.put("test3", "3&4&5");
     try {
       uri = client.buildUri(baseUri, endpoint, queryParams);
     } catch (URISyntaxException ex) {
@@ -70,10 +73,23 @@ public void testbuildUri() {
       Assert.assertTrue(errors.toString(), false);
     }
 
-    String url = uri.toString();
-    System.out.println(url);
-    Assert.assertTrue(url.equals("https://api.test.com/endpoint?test2=2&test1=1") ||
-           url.equals("https://api.test.com/endpoint?test1=1&test2=2"));
+    URL url = null;
+    try {
+      url = uri.toURL();
+    } catch (MalformedURLException ex) {
+      StringWriter errors = new StringWriter();
+      ex.printStackTrace(new PrintWriter(errors));
+      Assert.assertTrue(errors.toString(), false);
+    }
+
+    Assert.assertTrue(url.getProtocol().equals("https"));
+    Assert.assertTrue(url.getHost().equals("api.test.com"));
+    Assert.assertTrue(url.getPath().equals("/endpoint"));
+    Assert.assertTrue(this.queryParamHasCorrectValue(url, "test1", "1"));
+    Assert.assertTrue(this.queryParamHasCorrectValue(url, "test2", "2"));
+    Assert.assertTrue(this.queryParamHasCorrectValue(url, "test3", "3"));
+    Assert.assertTrue(this.queryParamHasCorrectValue(url, "test3", "4"));
+    Assert.assertTrue(this.queryParamHasCorrectValue(url, "test3", "5"));
   }
 
   @Test
@@ -174,4 +190,8 @@ public void testPut() {
   public void testDelete() {
     testMethod(Method.DELETE, 204);
   }
+
+  private boolean queryParamHasCorrectValue(URL url, String key, String value) {
+    return url.getQuery().indexOf(key + "=" + value) != -1;
+  }
 }