#1485 - Ensure proper encoding for request parameter expansion.

We now use the encoding rules defined in RFC 6570 (URI templates, API introduced in #1583) to prepare request parameters added to the URIs rendered.

src/main/java/org/springframework/hateoas/server/core/EncodingUtils.java

@@ -54,23 +54,6 @@ final class EncodingUtils {
 		}
 	}
 
-	/**
-	 * Encodes the given request parameter value.
-	 *
-	 * @param source must not be {@literal null}.
-	 * @return
-	 */
-	public static String encodeParameter(Object source) {
-
-		Assert.notNull(source, "Request parameter value must not be null!");
-
-		try {
-			return UriUtils.encodeQueryParam(source.toString(), ENCODING);
-		} catch (Throwable e) {
-			throw new IllegalStateException(e);
-		}
-	}
-
 	/**
 	 * Encodes the given fragment value.
 	 *

src/main/java/org/springframework/hateoas/server/core/WebHandler.java

@@ -17,7 +17,6 @@ package org.springframework.hateoas.server.core;
 
 import static org.springframework.hateoas.TemplateVariable.VariableType.*;
 import static org.springframework.hateoas.TemplateVariables.*;
-import static org.springframework.hateoas.server.core.EncodingUtils.*;
 import static org.springframework.web.util.UriComponents.UriTemplateVariables.*;
 
 import java.lang.annotation.Annotation;
@@ -30,6 +29,7 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.BiFunction;
@@ -114,7 +114,9 @@ public class WebHandler {
 			Iterator<Object> classMappingParameters = invocations.getObjectParameters();
 
 			while (classMappingParameters.hasNext()) {
-				values.put(names.next(), encodePath(classMappingParameters.next()));
+				String name = names.next();
+				TemplateVariable variable = TemplateVariable.segment(name);
+				values.put(name, variable.prepareAndEncode(classMappingParameters.next()));
 			}
 
 			Method method = invocation.getMethod();
@@ -123,8 +125,8 @@ public class WebHandler {
 			ConversionService resolved = conversionService;
 
 			for (HandlerMethodParameter parameter : parameters.getParameterAnnotatedWith(PathVariable.class, arguments)) {
-				values.put(parameter.getVariableName(),
-						encodePath(parameter.getValueAsString(arguments, resolved)));
+				TemplateVariable variable = TemplateVariable.segment(parameter.getVariableName());
+				values.put(variable.getName(), variable.prepareAndEncode(parameter.getValueAsString(arguments, resolved)));
 			}
 
 			List<String> optionalEmptyParameters = new ArrayList<>();
@@ -194,24 +196,28 @@ public class WebHandler {
 
 		if (value instanceof MultiValueMap) {
 
-			MultiValueMap<String, String> requestParams = (MultiValueMap<String, String>) value;
+			Map<String, List<?>> requestParams = (Map<String, List<?>>) value;
 
-			for (Map.Entry<String, List<String>> multiValueEntry : requestParams.entrySet()) {
-				for (String singleEntryValue : multiValueEntry.getValue()) {
-					builder.queryParam(multiValueEntry.getKey(), encodeParameter(singleEntryValue));
+			for (Entry<String, List<?>> entry : requestParams.entrySet()) {
+				for (Object element : entry.getValue()) {
+					TemplateVariable variable = TemplateVariable.pathVariable(entry.getKey());
+					builder.queryParam(entry.getKey(), variable.prepareAndEncode(element));
 				}
 			}
 
 			return;
-
 		}
 
 		if (value instanceof Map) {
 
-			Map<String, String> requestParams = (Map<String, String>) value;
+			Map<String, ?> requestParams = (Map<String, ?>) value;
 
-			for (Map.Entry<String, String> requestParamEntry : requestParams.entrySet()) {
-				builder.queryParam(requestParamEntry.getKey(), encodeParameter(requestParamEntry.getValue()));
+			for (Entry<String, ?> entry : requestParams.entrySet()) {
+
+				String key = entry.getKey();
+				TemplateVariable variable = TemplateVariable.requestParameter(key);
+
+				builder.queryParam(key, variable.prepareAndEncode(entry.getValue()));
 			}
 
 			return;
@@ -222,18 +228,17 @@ public class WebHandler {
 		}
 
 		String key = parameter.getVariableName();
+		TemplateVariable variable = TemplateVariable.requestParameter(key);
 
 		if (value instanceof Collection) {
 
 			if (parameter.isNonComposite()) {
-
-				TemplateVariable variable = TemplateVariable.requestParameter(key);
 				builder.queryParam(key, variable.prepareAndEncode(value));
 
 			} else {
 				for (Object element : (Collection<?>) value) {
 					if (key != null) {
-						builder.queryParam(key, encodeParameter(element));
+						builder.queryParam(key, variable.prepareAndEncode(element));
 					}
 				}
 			}
@@ -247,7 +252,7 @@ public class WebHandler {
 
 		} else {
 			if (key != null) {
-				builder.queryParam(key, encodeParameter(parameter.getValueAsString(arguments, conversionService)));
+				builder.queryParam(key, variable.prepareAndEncode(parameter.getValueAsString(arguments, conversionService)));
 			}
 		}
 	}

src/test/java/org/springframework/hateoas/server/mvc/WebMvcLinkBuilderUnitTest.java

@@ -19,6 +19,8 @@ import static org.assertj.core.api.Assertions.*;
 import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.*;
 
 import java.lang.reflect.Method;
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
@@ -28,6 +30,8 @@ import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.format.annotation.DateTimeFormat.ISO;
 import org.springframework.hateoas.IanaLinkRelations;
 import org.springframework.hateoas.Link;
 import org.springframework.hateoas.NonComposite;
@@ -638,6 +642,17 @@ class WebMvcLinkBuilderUnitTest extends TestUtils {
 		assertThat(link.getHref()).endsWith("?foo=first,second");
 	}
 
+	@Test // #1485
+	void encodesDatesCorrectly() {
+
+		OffsetDateTime reference = OffsetDateTime.now(ZoneId.of("CET"));
+		Link link = linkTo(methodOn(ControllerWithMethods.class).methodWithOffsetDateTime(reference)).withSelfRel();
+
+		assertThat(UriComponentsBuilder.fromUriString(link.getHref()).build().getQuery())
+				.contains("%3A", "%2B")
+				.doesNotContain(":", "+");
+	}
+
 	private static UriComponents toComponents(Link link) {
 		return UriComponentsBuilder.fromUriString(link.expand().getHref()).build();
 	}
@@ -733,6 +748,11 @@ class WebMvcLinkBuilderUnitTest extends TestUtils {
 		HttpEntity<Void> nonCompositeRequestParam(@NonComposite @RequestParam("foo") Collection<String> params) {
 			return null;
 		}
+
+		@RequestMapping("/offset")
+		HttpEntity<Void> methodWithOffsetDateTime(@RequestParam @DateTimeFormat(iso = ISO.DATE_TIME) OffsetDateTime date) {
+			return null;
+		}
 	}
 
 	@RequestMapping("/parent")