feat: Expose query params on Request (queryParams, queryParam, rawQuery)

Author: thced

src/main/java/com/retailsvc/http/Request.java

@@ -2,6 +2,9 @@
 
 import com.retailsvc.http.internal.DefaultResponseBuilder;
 import com.sun.net.httpserver.HttpExchange;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
 /**
@@ -16,6 +19,7 @@ public final class Request {
   private final String operationId;
   private final Map<String, String> pathParameters;
   private final Map<String, TypeMapper> bodyMappers;
+  private Map<String, String> queryParamCache;
   private boolean responseSent;
 
   public Request(
@@ -53,6 +57,49 @@ public String header(String name) {
     return exchange.getRequestHeaders().getFirst(name);
   }
 
+  /**
+   * Raw (percent-encoded) query string from the request URI, or {@code null} if the URI has no
+   * query component.
+   */
+  public String rawQuery() {
+    return exchange.getRequestURI().getRawQuery();
+  }
+
+  /**
+   * Decoded query parameters keyed by name. Empty if the URI has no query. For repeated keys, the
+   * first occurrence wins. Values are URL-decoded with UTF-8.
+   */
+  public Map<String, String> queryParams() {
+    if (queryParamCache == null) {
+      queryParamCache = parseQuery(rawQuery());
+    }
+    return queryParamCache;
+  }
+
+  /** First decoded value for {@code name}, or {@code null} if absent. */
+  public String queryParam(String name) {
+    return queryParams().get(name);
+  }
+
+  private static Map<String, String> parseQuery(String query) {
+    if (query == null || query.isBlank()) {
+      return Map.of();
+    }
+    Map<String, String> out = new LinkedHashMap<>();
+    for (String pair : query.split("&")) {
+      if (pair.isEmpty()) {
+        continue;
+      }
+      int eq = pair.indexOf('=');
+      String rawKey = eq < 0 ? pair : pair.substring(0, eq);
+      String rawValue = eq < 0 ? "" : pair.substring(eq + 1);
+      out.putIfAbsent(
+          URLDecoder.decode(rawKey, StandardCharsets.UTF_8),
+          URLDecoder.decode(rawValue, StandardCharsets.UTF_8));
+    }
+    return out;
+  }
+
   public ResponseBuilder respond(int status) {
     if (responseSent) {
       throw new IllegalStateException("Response already sent");

src/test/java/com/retailsvc/http/RequestTest.java

@@ -8,6 +8,7 @@
 import com.retailsvc.http.internal.DispatchHandler;
 import com.sun.net.httpserver.Headers;
 import com.sun.net.httpserver.HttpExchange;
+import java.net.URI;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.jupiter.api.Test;
@@ -48,6 +49,33 @@ void readsBoundContext() throws Exception {
     assertThat(seenPathParams.get()).containsEntry("id", "42");
   }
 
+  @Test
+  void exposesQueryParams() {
+    HttpExchange exchange = mock(HttpExchange.class);
+    when(exchange.getRequestURI())
+        .thenReturn(URI.create("http://h/x?name=Alice%20Smith&active=true&active=false"));
+    Request req = new Request(exchange, new byte[0], null, "op", Map.of(), Map.of());
+
+    assertThat(req.rawQuery()).isEqualTo("name=Alice%20Smith&active=true&active=false");
+    assertThat(req.queryParam("name")).isEqualTo("Alice Smith");
+    assertThat(req.queryParam("active")).isEqualTo("true");
+    assertThat(req.queryParam("missing")).isNull();
+    assertThat(req.queryParams())
+        .containsEntry("name", "Alice Smith")
+        .containsEntry("active", "true");
+  }
+
+  @Test
+  void queryParamsEmptyWhenNoQuery() {
+    HttpExchange exchange = mock(HttpExchange.class);
+    when(exchange.getRequestURI()).thenReturn(URI.create("http://h/x"));
+    Request req = new Request(exchange, new byte[0], null, "op", Map.of(), Map.of());
+
+    assertThat(req.rawQuery()).isNull();
+    assertThat(req.queryParams()).isEmpty();
+    assertThat(req.queryParam("anything")).isNull();
+  }
+
   @Test
   void respondAfterTerminalThrows() throws Exception {
     HttpExchange exchange = mock(HttpExchange.class);