SPR-6021 - Allow for using MultiValueMap in GET request for mapping multiple request params

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java

@@ -35,6 +35,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
+import java.util.Iterator;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -80,6 +81,7 @@ import org.springframework.ui.format.date.DateFormatter;
 import org.springframework.ui.format.support.GenericFormatterRegistry;
 import org.springframework.util.SerializationTestUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.util.MultiValueMap;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.Errors;
 import org.springframework.validation.FieldError;
@@ -1146,6 +1148,25 @@ public class ServletAnnotationControllerTests {
 	}
 
 
+	@Test
+	public void requestParamMap() throws Exception {
+		initServlet(RequestParamMapController.class);
+
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/map");
+		request.addParameter("key1", "value1");
+		request.addParameter("key2", new String[]{"value21", "value22"});
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		servlet.service(request, response);
+		assertEquals("key1=value1,key2=value21", response.getContentAsString());
+
+		request.setRequestURI("/multiValueMap");
+		response = new MockHttpServletResponse();
+
+		servlet.service(request, response);
+		assertEquals("key1=[value1],key2=[value21,value22]", response.getContentAsString());
+	}
+
 
 	/*
 	 * Controllers
@@ -1943,5 +1964,40 @@ public class ServletAnnotationControllerTests {
 		}
 	}
 
+	@Controller
+	public static class RequestParamMapController {
+
+		@RequestMapping("/map")
+		public void map(@RequestParam Map<String, String> params, Writer writer) throws IOException {
+			for (Iterator<Map.Entry<String, String>> it = params.entrySet().iterator(); it.hasNext();) {
+				Map.Entry<String, String> entry = it.next();
+				writer.write(entry.getKey() + "=" + entry.getValue());
+				if (it.hasNext()) {
+					writer.write(',');
+				}
+
+			}
+		}
+
+		@RequestMapping("/multiValueMap")
+		public void multiValueMap(@RequestParam MultiValueMap<String, String> params, Writer writer) throws IOException {
+			for (Iterator<Map.Entry<String, List<String>>> it1 = params.entrySet().iterator(); it1.hasNext();) {
+				Map.Entry<String, List<String>> entry = it1.next();
+				writer.write(entry.getKey() + "=[");
+				for (Iterator<String> it2 = entry.getValue().iterator(); it2.hasNext();) {
+					String value = it2.next();
+					writer.write(value);
+					if (it2.hasNext()) {
+						writer.write(',');
+					}
+				}
+				writer.write(']');
+				if (it1.hasNext()) {
+					writer.write(',');
+				}
+			}
+		}
+	}
+	
 
 }

org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java

@@ -26,6 +26,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.LinkedHashMap;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -46,6 +47,8 @@ import org.springframework.ui.Model;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.Errors;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
@@ -396,11 +399,15 @@ public class HandlerMethodInvoker {
 		return initBinderArgs;
 	}
 
+	@SuppressWarnings("unchecked")
 	private Object resolveRequestParam(String paramName, boolean required, String defaultValue,
 			MethodParameter methodParam, NativeWebRequest webRequest, Object handlerForInitBinderCall)
 			throws Exception {
 
 		Class<?> paramType = methodParam.getParameterType();
+		if (Map.class.isAssignableFrom(paramType)) {
+			return resolveRequestParamMap((Class<? extends Map>) paramType, webRequest);
+		}
 		if (paramName.length() == 0) {
 			paramName = getRequiredParameterName(methodParam);
 		}
@@ -428,6 +435,28 @@ public class HandlerMethodInvoker {
 		return binder.convertIfNecessary(paramValue, paramType, methodParam);
 	}
 
+	private Map resolveRequestParamMap(Class<? extends Map> mapType, NativeWebRequest webRequest) {
+		Map<String, String[]> parameterMap = webRequest.getParameterMap();
+		if (MultiValueMap.class.isAssignableFrom(mapType)) {
+			MultiValueMap<String, String> result = new LinkedMultiValueMap<String, String>(parameterMap.size());
+			for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
+				for (String value : entry.getValue()) {
+					result.add(entry.getKey(), value);
+				}
+			}
+			return result;
+		}
+		else {
+			Map<String, String> result = new LinkedHashMap<String, String>(parameterMap.size());
+			for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
+				if (entry.getValue().length > 0) {
+					result.put(entry.getKey(), entry.getValue()[0]);
+				}
+			}
+			return result;
+		}
+	}
+
 	private Object resolveRequestHeader(String headerName, boolean required, String defaultValue,
 			MethodParameter methodParam, NativeWebRequest webRequest, Object handlerForInitBinderCall)
 			throws Exception {