Build query string from context instead of original request

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/SimpleHostRoutingFilter.java

@@ -18,8 +18,10 @@ package org.springframework.cloud.netflix.zuul.filters.route;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
 import java.net.Socket;
 import java.net.URL;
+import java.net.URLEncoder;
 import java.net.UnknownHostException;
 import java.security.KeyManagementException;
 import java.security.KeyStore;
@@ -259,10 +261,20 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 		return httpclient.execute(httpHost, httpRequest);
 	}
 
-	private String getQueryString() {
+	private String getQueryString() throws UnsupportedEncodingException {
 		HttpServletRequest request = RequestContext.getCurrentContext().getRequest();
-		String query = request.getQueryString();
-		return (query != null) ? "?" + query : "";
+		MultiValueMap<String, String> params=helper.buildZuulRequestQueryParams(request);
+		StringBuilder query=new StringBuilder();
+		for (Map.Entry<String, List<String>> entry : params.entrySet()) {
+			String key=URLEncoder.encode(entry.getKey(), "UTF-8");
+			for (String value : entry.getValue()) {
+				query.append("&");
+				query.append(key);
+				query.append("=");
+				query.append(URLEncoder.encode(value, "UTF-8"));
+			}
+		}
+		return (query.length()>0) ? "?" + query.substring(1) : "";
 	}
 
 	private HttpHost getHttpHost(URL host) {

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/SampleZuulProxyApplicationTests.java

@@ -19,6 +19,9 @@ package org.springframework.cloud.netflix.zuul;
 import static org.junit.Assert.assertEquals;
 
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -31,6 +34,8 @@ import org.springframework.boot.test.SpringApplicationConfiguration;
 import org.springframework.boot.test.TestRestTemplate;
 import org.springframework.cloud.netflix.ribbon.RibbonClient;
 import org.springframework.cloud.netflix.ribbon.RibbonClients;
+import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
+import org.springframework.cloud.netflix.zuul.RoutesEndpoint;
 import org.springframework.cloud.netflix.zuul.filters.ProxyRouteLocator;
 import org.springframework.cloud.netflix.zuul.filters.ZuulProperties.ZuulRoute;
 import org.springframework.context.annotation.Bean;
@@ -42,10 +47,12 @@ import org.springframework.http.ResponseEntity;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import com.netflix.appinfo.EurekaInstanceConfig;
@@ -53,6 +60,7 @@ import com.netflix.loadbalancer.BaseLoadBalancer;
 import com.netflix.loadbalancer.ILoadBalancer;
 import com.netflix.loadbalancer.Server;
 import com.netflix.zuul.ZuulFilter;
+import com.netflix.zuul.context.RequestContext;
 
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringApplicationConfiguration(classes = SampleZuulProxyApplication.class)
@@ -153,6 +161,28 @@ public class SampleZuulProxyApplicationTests {
 		assertEquals("Hello space", result.getBody());
 	}
 
+	@Test
+	public void simpleHostRouteWithOriginalQString() {
+		routes.addRoute("/self/**", "http://localhost:" + this.port);
+		this.endpoint.reset();
+		ResponseEntity<String> result = new TestRestTemplate().exchange(
+				"http://localhost:" + this.port + "/self/qstring?original=value1&original=value2", HttpMethod.GET,
+				new HttpEntity<>((Void) null), String.class);
+		assertEquals(HttpStatus.OK, result.getStatusCode());
+		assertEquals("Received {original=[value1, value2]}", result.getBody());
+	}
+
+	@Test
+	public void simpleHostRouteWithOverriddenQString() {
+		routes.addRoute("/self/**", "http://localhost:" + this.port);
+		this.endpoint.reset();
+		ResponseEntity<String> result = new TestRestTemplate().exchange(
+				"http://localhost:" + this.port + "/self/qstring?override=true&different=key", HttpMethod.GET,
+				new HttpEntity<>((Void) null), String.class);
+		assertEquals(HttpStatus.OK, result.getStatusCode());
+		assertEquals("Received {key=[overridden]}", result.getBody());
+	}
+
 }
 
 // Don't use @SpringBootApplication because we don't want to component scan
@@ -190,6 +220,11 @@ class SampleZuulProxyApplication {
 		return "Posted " + id + "!";
 	}
 
+	@RequestMapping(value = "/qstring")
+	public String qstring(@RequestParam MultiValueMap<String,String> params) {
+		return "Received "+params.toString();	
+	}
+
 	@RequestMapping("/")
 	public String home() {
 		return "Hello world";
@@ -215,6 +250,11 @@ class SampleZuulProxyApplication {
 
 			@Override
 			public Object run() {
+				if (RequestContext.getCurrentContext().getRequest().getParameterMap().containsKey("override")) {
+					Map<String,List<String>> overridden=new HashMap<>();
+					overridden.put("key", Arrays.asList("overridden"));
+					RequestContext.getCurrentContext().setRequestQueryParams(overridden);
+				}
 				return null;
 			}