Nima - have validation Accept-Language helper method

http-api/src/main/java/io/avaje/http/api/ValidationException.java

@@ -37,8 +37,7 @@ public ValidationException(int status, String message, Map<String, Object> error
   }
 
   /** Create with a status message and errors. */
-  public ValidationException(
-      int status, String message, Throwable cause, Map<String, Object> errors) {
+  public ValidationException(int status, String message, Throwable cause, Map<String, Object> errors) {
     super(message, cause);
     this.status = status;
     this.errors = errors;

http-generator-core/src/main/java/io/avaje/http/generator/core/ElementReader.java

@@ -282,19 +282,17 @@ void buildApiDocumentation(MethodDocBuilder methodDoc) {
 
   void writeValidate(Append writer) {
     if (!contextType && typeHandler == null) {
+      final var indent = platform().indent();
       if (useValidation) {
-        writer.append("var validLanguage = ");
+        writer.append("%s  var validLanguage = ", indent);
         platform().writeAcceptLanguage(writer);
         writer.append(";").eol();
-        writer.append("    validator.validate(%s, validLanguage", varName);
-
+        writer.append("%s  validator.validate(%s, validLanguage", indent, varName);
         validationGroups.forEach(g -> writer.append(", %s", Util.shortName(g)));
-
         writer.append(");").eol();
       } else {
-        writer.append("// no validation required on %s", varName).eol();
+        writer.append("%s  // no validation required on %s", indent, varName).eol();
       }
-      writer.append("      ");
     }
   }
 

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/ControllerMethodWriter.java

@@ -76,7 +76,6 @@ void writeHandler(boolean requestScoped) {
 
     if (method.includeValidate()) {
       for (final MethodParam param : params) {
-        writer.append("    ");
         param.writeValidate(writer);
       }
     }

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java

@@ -47,6 +47,9 @@ class ControllerWriter extends BaseControllerWriter {
     reader.addImportType("io.helidon.nima.webserver.http.ServerResponse");
     reader.addImportType("io.helidon.nima.webserver.http.HttpService");
     reader.addImportType("io.helidon.common.http.Http.Header");
+    if (reader.isIncludeValidator()) {
+      reader.addImportType("io.helidon.common.http.Http");
+    }
   }
 
   void write() {
@@ -96,6 +99,11 @@ private void writeClassStart() {
       controllerName = "factory";
       controllerType += Constants.FACTORY_SUFFIX;
     }
+
+    if (reader.isIncludeValidator()) {
+      writer.append("  private static final Http.HeaderName HEADER_ACCEPT_LANGUAGE = Header.create(\"Accept-Language\");").eol();
+    }
+
     writer.append("  private final %s %s;", controllerType, controllerName).eol();
 
     if (reader.isIncludeValidator()) {
@@ -142,6 +150,12 @@ private void writeClassStart() {
       }
     }
     writer.append("  }").eol().eol();
+
+    if (reader.isIncludeValidator()) {
+      writer.append("  private String language(ServerRequest req) {").eol();
+      writer.append("    return req.headers().first(HEADER_ACCEPT_LANGUAGE).orElse(null);").eol();
+      writer.append("  }").eol().eol();
+    }
   }
 
   private boolean isInputStream(String type) {

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/NimaPlatformAdapter.java

@@ -137,8 +137,7 @@ public void writeReadCollectionParameter(Append writer, ParamType paramType, Str
   }
 
   @Override
-  public void writeReadCollectionParameter(
-      Append writer, ParamType paramType, String paramName, List<String> paramDefault) {
+  public void writeReadCollectionParameter(Append writer, ParamType paramType, String paramName, List<String> paramDefault) {
     switch (paramType) {
       case QUERYPARAM:
         writer.append(
@@ -162,6 +161,6 @@ public void writeReadCollectionParameter(
 
   @Override
   public void writeAcceptLanguage(Append writer) {
-    writer.append("req.headers().first(Header.create(\"%s\")).orElse(null)", Constants.ACCEPT_LANGUAGE);
+    writer.append("language(req)");
   }
 }

http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerMethodWriter.java

@@ -46,13 +46,12 @@ void write(boolean requestScoped) {
     for (final MethodParam param : params) {
       param.writeCtxGet(writer, segments);
     }
-    writer.append("      ");
     if (method.includeValidate()) {
       for (final MethodParam param : params) {
         param.writeValidate(writer);
       }
     }
-
+    writer.append("      ");
     if (!method.isVoid()) {
       writer.append("var result = ");
     }

http-generator-jex/src/main/java/io/avaje/http/generator/jex/ControllerMethodWriter.java

@@ -44,12 +44,12 @@ void write(boolean requestScoped) {
     for (MethodParam param : params) {
       param.writeCtxGet(writer, segments);
     }
-    writer.append("      ");
     if (method.includeValidate()) {
       for (MethodParam param : params) {
         param.writeValidate(writer);
       }
     }
+    writer.append("      ");
     if (!method.isVoid()) {
       writeContextReturn();
     }