8359242: JFR: Missing help text for method trace and timing

src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlElement.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -107,6 +107,13 @@ final String getContent() {
         return content;
     }
 
+    final String getContentOrEmptyQuote() {
+        if (content == null || content.isEmpty()) {
+            return "\"\"";
+        }
+        return content;
+    }
+
     final void addListener(XmlElement listener) {
         listeners.add(listener);
         listener.addProducer(this);

src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlText.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,6 +24,8 @@
  */
 package jdk.jfr.internal.jfc.model;
 
+import jdk.jfr.internal.tracing.Filter;
+
 // Corresponds to <text>
 final class XmlText extends XmlInput {
 
@@ -35,7 +37,7 @@ public String getOptionSyntax() {
         sb.append(getContentType().orElse("text"));
         sb.append(">");
         sb.append("  (");
-        String content = getContent();
+        String content = getContentOrEmptyQuote();
         if (isTimespan()) {
             // "20 ms" becomes "20ms"
             content = content.replaceAll("\\s", "");
@@ -57,7 +59,7 @@ public void configure(String value) {
     @Override
     public void configure(UserInterface ui) throws AbortException {
         ui.println();
-        ui.println(getLabel() + ": " + getContent() + "  (default)");
+        ui.println(getLabel() + ": " + getContentOrEmptyQuote() + "  (default)");
         while (!readInput(ui)) {
             ;
         }
@@ -71,9 +73,21 @@ protected Result evaluate() {
     private boolean readInput(UserInterface ui) throws AbortException {
         String line = ui.readLine();
         if (line.isBlank()) {
-            ui.println("Using default: " + getContent());
+            ui.println("Using default: " + getContentOrEmptyQuote());
             return true;
         }
+        if (isMethodFilter()) {
+            if (!Filter.isValid(line)) {
+                ui.println("""
+                Not a valid method filter. A filter can be an annotation \
+                (@jakarta.ws.rs.GET), a full qualified class name (com.example.Foo), \
+                a fully qualified method reference (java.lang.HashMap::resize) or a \
+                class initializer (::<clinit>). Use <init> for constructors. \
+                Separate multiple filters with semicolon.\
+                """);
+                return false;
+            }
+        }
         if (isTimespan()) {
             try {
                 line = Utilities.parseTimespan(line);
@@ -90,4 +104,8 @@ private boolean readInput(UserInterface ui) throws AbortException {
     private boolean isTimespan() {
         return getContentType().orElse("text").equals("timespan");
     }
+
+    private boolean isMethodFilter() {
+        return getContentType().orElse("text").equals("method-filter");
+    }
 }

src/jdk.jfr/share/classes/jdk/jfr/internal/settings/MethodSetting.java

@@ -33,6 +33,7 @@
 import jdk.jfr.internal.PlatformEventType;
 import jdk.jfr.internal.Type;
 import jdk.jfr.internal.tracing.Modification;
+import jdk.jfr.internal.tracing.Filter;
 import jdk.jfr.internal.tracing.PlatformTracer;
 
 @MetadataDefinition
@@ -47,8 +48,9 @@ public MethodSetting(PlatformEventType eventType, Modification modification, Str
         this.modification = modification;
     }
 
+    @Override
     public boolean isValid(String text) {
-        return PlatformTracer.isValidFilter(text);
+        return Filter.isValid(text);
     }
 
     @Override

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/Filter.java

@@ -30,7 +30,11 @@
  * Class that represents the filter a user can specify for the MethodTrace and
  * MethodTiming event.
  */
-record Filter(String className, String methodName, String annotationName, Modification modification) {
+public record Filter(String className, String methodName, String annotationName, Modification modification) {
+
+    public static boolean isValid(String filter) {
+        return of(filter, Modification.NONE) != null;
+    }
 
     static Filter of(String filter, Modification modification) {
         if (filter.startsWith("@")) {

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/PlatformTracer.java

@@ -158,10 +158,6 @@ public static void addTiming(long id, long duration) {
         }
     }
 
-    public static boolean isValidFilter(String text) {
-        return Filter.of(text, null) != null;
-    }
-
     public static void setFilters(Modification modification, List<String> filters) {
         ensureInitialized();
         publishClasses(applyFilter(modification, filters));

src/jdk.jfr/share/conf/jfr/default.jfc

@@ -1189,9 +1189,11 @@
 
       <text name="locking-threshold" label="Locking Threshold" contentType="timespan" minimum="0 s">20 ms</text>
 
-      <text name="method-timing" label="Method Timing" contentType="text"></text>
+      <text name="method-timing" label="Method Timing Filter" contentType="method-filter"
+            description="A filter can be an annotation (@jakarta.ws.rs.GET), a full qualified class name (com.example.Foo), a fully qualified method reference (java.lang.HashMap::resize) or a class initializer (::&lt;clinit&gt;). Use &lt;init&gt; for constructors. Separate multiple filters with semicolon."></text>
 
-      <text name="method-trace" label="Method Trace" contentType="text"></text>
+      <text name="method-trace" label="Method Trace Filter" contentType="method-filter"
+            description="A filter can be an annotation (@jakarta.ws.rs.GET), a full qualified class name (com.example.Foo), a fully qualified method reference (java.lang.HashMap::resize) or a class initializer (::&lt;clinit&gt;). Use &lt;init&gt; for constructors. Separate multiple filters with semicolon."></text>
 
       <flag name="class-loading" label="Class Loading">false</flag>
     </control>

src/jdk.jfr/share/conf/jfr/profile.jfc

@@ -1188,9 +1188,11 @@
 
       <text name="locking-threshold" label="Locking Threshold" contentType="timespan" minimum="0 s">10 ms</text>
 
-      <text name="method-timing" label="Method Timing" contentType="text"></text>
+      <text name="method-timing" label="Method Timing Filter" contentType="method-filter"
+            description="A filter can be an annotation (@jakarta.ws.rs.GET), a full qualified class name (com.example.Foo), a fully qualified method reference (java.lang.HashMap::resize) or a class initializer (::&lt;clinit&gt;). Use &lt;init&gt; for constructors. Separate multiple filters with semicolon."></text>
 
-      <text name="method-trace" label="Method Trace" contentType="text"></text>
+      <text name="method-trace" label="Method Trace Filter" contentType="method-filter"
+            description="A filter can be an annotation (@jakarta.ws.rs.GET), a full qualified class name (com.example.Foo), a fully qualified method reference (java.lang.HashMap::resize) or a class initializer (::&lt;clinit&gt;). Use &lt;init&gt; for constructors. Separate multiple filters with semicolon."></text>
 
       <flag name="class-loading" label="Class Loading">false</flag>
     </control>