Introduce @Separator annotation for query parameters

docs/src/main/asciidoc/resteasy-reactive-migration.adoc

@@ -87,6 +87,10 @@ The following table matches the legacy RESTEasy annotations with the new RESTEas
 |`org.jboss.resteasy.reactive.RestStreamElementType`
 |
 
+|`org.jboss.resteasy.annotations.Separator`
+|`org.jboss.resteasy.reactive.Separator`
+|
+
 |===
 
 NOTE: The previous table does not include the `org.jboss.resteasy.annotations.Form` annotation because there is no RESTEasy Reactive specific replacement for it.

extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/main/java/io/quarkus/resteasy/reactive/server/deployment/CustomResourceProducersGenerator.java

@@ -136,8 +136,9 @@ public static void generate(Map<DotName, MethodInfo> resourcesThatNeedCustomProd
                 ResultHandle quarkusRestContextHandle = m.invokeVirtualMethod(getContextMethodCreator.getMethodDescriptor(),
                         m.getThis());
                 ResultHandle extractorHandle = m.newInstance(
-                        MethodDescriptor.ofConstructor(QueryParamExtractor.class, String.class, boolean.class, boolean.class),
-                        m.getMethodParam(0), m.load(true), m.load(false));
+                        MethodDescriptor.ofConstructor(QueryParamExtractor.class, String.class, boolean.class, boolean.class,
+                                String.class),
+                        m.getMethodParam(0), m.load(true), m.load(false), m.loadNull());
                 ResultHandle resultHandle = m.invokeVirtualMethod(MethodDescriptor.ofMethod(QueryParamExtractor.class,
                         "extractParameter", Object.class, ResteasyReactiveRequestContext.class), extractorHandle,
                         quarkusRestContextHandle);

extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/test/java/io/quarkus/resteasy/reactive/server/test/simple/SeparatorQueryParamTest.java

@@ -0,0 +1,69 @@
+package io.quarkus.resteasy.reactive.server.test.simple;
+
+import static io.restassured.RestAssured.*;
+
+import java.util.List;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+
+import org.hamcrest.Matchers;
+import org.jboss.resteasy.reactive.RestQuery;
+import org.jboss.resteasy.reactive.RestResponse;
+import org.jboss.resteasy.reactive.Separator;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+public class SeparatorQueryParamTest {
+
+    @RegisterExtension
+    static QuarkusUnitTest test = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClass(HelloResource.class));
+
+    @Test
+    public void noQueryParams() {
+        get("/hello")
+                .then()
+                .statusCode(200)
+                .body(Matchers.equalTo("hello world"))
+                .header("x-size", "0");
+    }
+
+    @Test
+    public void singleQueryParam() {
+        get("/hello?name=foo")
+                .then()
+                .statusCode(200)
+                .body(Matchers.equalTo("hello foo"))
+                .header("x-size", "1");
+    }
+
+    @Test
+    public void multipleQueryParams() {
+        get("/hello?name=foo,bar&name=one,two,three&name=yolo")
+                .then()
+                .statusCode(200)
+                .body(Matchers.equalTo("hello foo bar one two three yolo"))
+                .header("x-size", "6");
+    }
+
+    @Path("hello")
+    public static class HelloResource {
+
+        @GET
+        public RestResponse<String> hello(@RestQuery("name") @Separator(",") List<String> names) {
+            int size = names.size();
+            String body = "";
+            if (names.isEmpty()) {
+                body = "hello world";
+            } else {
+                body = "hello " + String.join(" ", names);
+            }
+            return RestResponse.ResponseBuilder.ok(body).header("x-size", size).build();
+        }
+
+    }
+}

independent-projects/resteasy-reactive/client/processor/src/main/java/org/jboss/resteasy/reactive/client/processor/scanning/ClientEndpointIndexer.java

@@ -143,7 +143,7 @@ protected MethodParameter createMethodParameter(ClassInfo currentClassInfo, Clas
                 elementType, declaredTypes.getDeclaredType(), declaredTypes.getDeclaredUnresolvedType(), signature, type,
                 single,
                 defaultValue, parameterResult.isObtainedAsCollection(), parameterResult.isOptional(), encoded,
-                mimePart, partFileName);
+                mimePart, partFileName, null);
     }
 
     private String getPartFileName(Map<DotName, AnnotationInstance> annotations) {

independent-projects/resteasy-reactive/common/processor/src/main/java/org/jboss/resteasy/reactive/common/processor/EndpointIndexer.java

@@ -1500,6 +1500,15 @@ protected String getPartMime(Map<DotName, AnnotationInstance> annotations) {
         return mimeType;
     }
 
+    protected String getSeparator(Map<DotName, AnnotationInstance> annotations) {
+        AnnotationInstance separator = annotations.get(ResteasyReactiveDotNames.SEPARATOR);
+        String result = null;
+        if (separator != null && separator.value() != null) {
+            result = separator.value().asString();
+        }
+        return result;
+    }
+
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static abstract class Builder<T extends EndpointIndexer<T, ?, METHOD>, B extends Builder<T, B, METHOD>, METHOD extends ResourceMethod> {
         private Function<String, BeanFactory<Object>> factoryCreator;

independent-projects/resteasy-reactive/common/processor/src/main/java/org/jboss/resteasy/reactive/common/processor/ResteasyReactiveDotNames.java

@@ -92,6 +92,7 @@
 import org.jboss.resteasy.reactive.RestResponse;
 import org.jboss.resteasy.reactive.RestSseElementType;
 import org.jboss.resteasy.reactive.RestStreamElementType;
+import org.jboss.resteasy.reactive.Separator;
 import org.reactivestreams.Publisher;
 
 import io.smallrye.common.annotation.Blocking;
@@ -136,6 +137,7 @@ public final class ResteasyReactiveDotNames {
     public static final DotName MULTI_PART_FORM_PARAM = DotName.createSimple(MultipartForm.class.getName());
     public static final DotName PART_TYPE_NAME = DotName.createSimple(PartType.class.getName());
     public static final DotName PART_FILE_NAME = DotName.createSimple(PartFilename.class.getName());
+    public static final DotName SEPARATOR = DotName.createSimple(Separator.class.getName());
     public static final DotName REST_MATRIX_PARAM = DotName.createSimple(RestMatrix.class.getName());
     public static final DotName REST_COOKIE_PARAM = DotName.createSimple(RestCookie.class.getName());
     public static final DotName GET = DotName.createSimple(javax.ws.rs.GET.class.getName());

independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/Separator.java

@@ -0,0 +1,18 @@
+package org.jboss.resteasy.reactive;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.List;
+
+/**
+ * When used on a {@link List} parameter annotated with {@link RestQuery}, RESTEasy Reactive will split the value of the
+ * parameter (using the value of the annotation) and populate the list with those values.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.PARAMETER })
+public @interface Separator {
+
+    String value();
+}

independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/model/MethodParameter.java

@@ -25,6 +25,7 @@ public class MethodParameter {
     private boolean isObtainedAsCollection;
     public String mimeType;
     public String partFileName;
+    public String separator;
 
     public MethodParameter() {
     }
@@ -33,7 +34,7 @@ public MethodParameter(String name, String type, String declaredType, String dec
             ParameterType parameterType,
             boolean single,
             String defaultValue, boolean isObtainedAsCollection, boolean optional, boolean encoded,
-            String mimeType, String partFileName) {
+            String mimeType, String partFileName, String separator) {
         this.name = name;
         this.type = type;
         this.declaredType = declaredType;
@@ -47,6 +48,7 @@ public MethodParameter(String name, String type, String declaredType, String dec
         this.encoded = encoded;
         this.mimeType = mimeType;
         this.partFileName = partFileName;
+        this.separator = separator;
     }
 
     public String getName() {

independent-projects/resteasy-reactive/server/processor/src/main/java/org/jboss/resteasy/reactive/server/processor/ServerEndpointIndexer.java

@@ -315,11 +315,12 @@ protected MethodParameter createMethodParameter(ClassInfo currentClassInfo, Clas
         ParameterConverterSupplier converter = parameterResult.getConverter();
         DeclaredTypes declaredTypes = getDeclaredTypes(paramType, currentClassInfo, actualEndpointInfo);
         String mimeType = getPartMime(parameterResult.getAnns());
+        String separator = getSeparator(parameterResult.getAnns());
         return new ServerMethodParameter(name,
                 elementType, declaredTypes.getDeclaredType(), declaredTypes.getDeclaredUnresolvedType(),
                 type, single, signature,
                 converter, defaultValue, parameterResult.isObtainedAsCollection(), parameterResult.isOptional(), encoded,
-                parameterResult.getCustomParameterExtractor(), mimeType);
+                parameterResult.getCustomParameterExtractor(), mimeType, separator);
     }
 
     protected void handleOtherParam(Map<String, String> existingConverters, String errorLocation, boolean hasRuntimeConverters,

independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/core/parameters/QueryParamExtractor.java

@@ -1,21 +1,47 @@
 package org.jboss.resteasy.reactive.server.core.parameters;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
 import org.jboss.resteasy.reactive.server.core.ResteasyReactiveRequestContext;
 
 public class QueryParamExtractor implements ParameterExtractor {
 
     private final String name;
     private final boolean single;
     private final boolean encoded;
+    private final String separator;
 
-    public QueryParamExtractor(String name, boolean single, boolean encoded) {
+    public QueryParamExtractor(String name, boolean single, boolean encoded, String separator) {
         this.name = name;
         this.single = single;
         this.encoded = encoded;
+        this.separator = separator;
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public Object extractParameter(ResteasyReactiveRequestContext context) {
-        return context.getQueryParameter(name, single, encoded);
+        Object queryParameter = context.getQueryParameter(name, single, encoded);
+        if (separator != null) {
+            if (queryParameter instanceof List) { // it's List<String>
+                List<String> list = (List<String>) queryParameter;
+                List<String> result = new ArrayList<>(list.size());
+                for (int i = 0; i < list.size(); i++) {
+                    String[] parts = list.get(i).split(separator);
+                    result.addAll(Arrays.asList(parts));
+                }
+                queryParameter = result;
+            } else if (queryParameter instanceof String) {
+                List<String> result = new ArrayList<>(1);
+                String[] parts = ((String) queryParameter).split(separator);
+                result.addAll(Arrays.asList(parts));
+                queryParameter = result;
+            } else {
+                // can't really happen
+            }
+        }
+        return queryParameter;
     }
 }

independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/core/startup/RuntimeResourceDeployment.java

@@ -676,7 +676,7 @@ public ParameterExtractor parameterExtractor(Map<String, Integer> pathParameterI
             case ASYNC_RESPONSE:
                 return new AsyncResponseExtractor();
             case QUERY:
-                extractor = new QueryParamExtractor(param.name, param.isSingle(), param.encoded);
+                extractor = new QueryParamExtractor(param.name, param.isSingle(), param.encoded, param.separator);
                 return extractor;
             case BODY:
                 return new BodyParamExtractor();

independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/model/ServerMethodParameter.java

@@ -21,10 +21,10 @@ public ServerMethodParameter(String name, String type, String declaredType, Stri
             ParameterConverterSupplier converter, String defaultValue, boolean obtainedAsCollection, boolean optional,
             boolean encoded,
             ParameterExtractor customParameterExtractor,
-            String mimeType) {
+            String mimeType, String separator) {
         super(name, type, declaredType, declaredUnresolvedType, signature, parameterType, single, defaultValue,
                 obtainedAsCollection, optional,
-                encoded, mimeType, null /* not useful for server params */);
+                encoded, mimeType, null /* not useful for server params */, separator);
         this.converter = converter;
         this.customParameterExtractor = customParameterExtractor;
     }