switch to 400 error instead of 500 when using a non registered writer type

epugh · epugh · commit 095a9583d013 · 2026-02-07T15:50:43.000-05:00
diff --git a/solr/core/src/java/org/apache/solr/response/ResponseWritersRegistry.java b/solr/core/src/java/org/apache/solr/response/ResponseWritersRegistry.java
@@ -107,7 +107,7 @@ public static QueryResponseWriter getWriter(String writerName, SolrCore core) {
     if (writer == null) {
       if (!hasWriter(writerName)) {
         throw new SolrException(
-            SolrException.ErrorCode.SERVER_ERROR, "Unknown response writer type: " + writerName);
+            SolrException.ErrorCode.BAD_REQUEST, "Unknown response writer type: " + writerName);
       } else {
         writer = getWriter(writerName);
       }
diff --git a/solr/core/src/test/org/apache/solr/handler/V2ApiIntegrationTest.java b/solr/core/src/test/org/apache/solr/handler/V2ApiIntegrationTest.java
@@ -112,16 +112,16 @@ public void testIntrospect() throws Exception {
   @Test
   public void testInvalidWTParamReturnsError() throws Exception {
     V2Request request = new V2Request.Builder("/c/" + COLL_NAME + "/get/_introspect").build();
-    // Using an invalid wt parameter should return a 500 error
+    // Using an invalid wt parameter should return a 400 error
     request.setResponseParser(new InputStreamResponseParser("bleh"));
     NamedList<Object> res = cluster.getSolrClient().request(request);
     String respString = InputStreamResponseParser.consumeResponseToString(res);
 
-    // Should get a 500 Server Error for unknown writer type
+    // Should get a 400 Server Error for unknown writer type
     assertTrue(
         "Expected error message about unknown writer type",
         respString.contains("Unknown response writer type"));
-    assertTrue("Expected 500 error code", respString.contains("500"));
+    assertTrue("Expected 400 error code", respString.contains("400"));
   }
 
   @Test
@@ -132,7 +132,7 @@ public void testWTParam() throws Exception {
     Map<?, ?> resp = resAsMap(cluster.getSolrClient(), request);
     String respString = resp.toString();
 
-    assertFalse(respString.contains("<body><h2>HTTP ERROR 500</h2>"));
+    assertFalse(respString.contains("400"));
     assertFalse(
         respString.contains(
             "<p>Problem accessing /solr/____v2/c/collection1/get/_introspect. Reason:"));
diff --git a/solr/core/src/test/org/apache/solr/response/TestPrometheusResponseWriter.java b/solr/core/src/test/org/apache/solr/response/TestPrometheusResponseWriter.java
@@ -194,8 +194,8 @@ public void testUnsupportedMetricsFormat() throws Exception {
 
     try (SolrClient adminClient = getHttpSolrClient(solrTestRule.getBaseUrl())) {
       NamedList<Object> res = adminClient.request(req);
-      // Unknown wt parameter should return a 500 error
-      assertEquals(500, res.get("responseStatus"));
+      // Unknown wt parameter should return a 400 error
+      assertEquals(400, res.get("responseStatus"));
     }
   }
 }
diff --git a/solr/core/src/test/org/apache/solr/response/TestResponseWritersRegistry.java b/solr/core/src/test/org/apache/solr/response/TestResponseWritersRegistry.java
@@ -46,17 +46,4 @@ public void testBuiltInWriterFallbackBehavior() {
     QueryResponseWriter unknownWriter = ResponseWritersRegistry.getWriter("nonexistent");
     assertThat("unknown writer should be null", unknownWriter, is(nullValue()));
   }
-
-  @Test
-  public void testBuiltInWriterLimitedSet() {
-    QueryResponseWriter standardWriter = ResponseWritersRegistry.getWriter("json");
-
-    // Built-in writers should NOT include extended format writers (csv, geojson, etc.)
-    // These should all fall back to json
-    // I think this json thing is weird...   I think it should throw an exception!
-    assertThat(
-        "geojson should fall back to json",
-        ResponseWritersRegistry.getWriter("geojson"),
-        is(nullValue()));
-  }
 }

Original file line number	Diff line number	Diff line change
`@@ -107,7 +107,7 @@ public static QueryResponseWriter getWriter(String writerName, SolrCore core) {`
`107`	`107`	`if (writer == null) {`
`108`	`108`	`if (!hasWriter(writerName)) {`
`109`	`109`	`throw new SolrException(`
`110`		`- SolrException.ErrorCode.SERVER_ERROR, "Unknown response writer type: " + writerName);`
	`110`	`+ SolrException.ErrorCode.BAD_REQUEST, "Unknown response writer type: " + writerName);`
`111`	`111`	`} else {`
`112`	`112`	`writer = getWriter(writerName);`
`113`	`113`	`}`
Original file line number	Diff line number	Diff line change
`@@ -194,8 +194,8 @@ public void testUnsupportedMetricsFormat() throws Exception {`
`194`	`194`
`195`	`195`	`try (SolrClient adminClient = getHttpSolrClient(solrTestRule.getBaseUrl())) {`
`196`	`196`	`NamedList<Object> res = adminClient.request(req);`
`197`		`- // Unknown wt parameter should return a 500 error`
`198`		`- assertEquals(500, res.get("responseStatus"));`
	`197`	`+ // Unknown wt parameter should return a 400 error`
	`198`	`+ assertEquals(400, res.get("responseStatus"));`
`199`	`199`	`}`
`200`	`200`	`}`
`201`	`201`	`}`