Merge pull request #5837 from mbien/enable-preview-hint-update

add missing error code to enable-preview hint
diff --git a/java/ant.hints/src/org/netbeans/modules/ant/hints/errors/EnablePreviewAntProj.java b/java/ant.hints/src/org/netbeans/modules/ant/hints/errors/EnablePreviewAntProj.java
index ce88520..7f4e2d1 100644
--- a/java/ant.hints/src/org/netbeans/modules/ant/hints/errors/EnablePreviewAntProj.java
+++ b/java/ant.hints/src/org/netbeans/modules/ant/hints/errors/EnablePreviewAntProj.java
@@ -55,7 +55,8 @@
 
     private static final Set<String> ERROR_CODES = new HashSet<String>(Arrays.asList(
             "compiler.err.preview.feature.disabled",          // NOI18N
-            "compiler.err.preview.feature.disabled.plural")); // NOI18N
+            "compiler.err.preview.feature.disabled.plural",   // NOI18N
+            "compiler.err.is.preview"));                      // NOI18N
     private static final String ENABLE_PREVIEW_FLAG = "--enable-preview";   // NOI18N
     private static final String JAVAC_COMPILER_ARGS = "javac.compilerargs"; // NOI18N
     private static final String RUN_JVMARGS = "run.jvmargs"; // NOI18N
diff --git a/java/java.hints/src/org/netbeans/modules/java/hints/errors/EnablePreviewSingleSourceFile.java b/java/java.hints/src/org/netbeans/modules/java/hints/errors/EnablePreviewSingleSourceFile.java
index 247db95..a311d66 100644
--- a/java/java.hints/src/org/netbeans/modules/java/hints/errors/EnablePreviewSingleSourceFile.java
+++ b/java/java.hints/src/org/netbeans/modules/java/hints/errors/EnablePreviewSingleSourceFile.java
@@ -54,7 +54,8 @@
 
     private static final Set<String> ERROR_CODES = new HashSet<String>(Arrays.asList(
             "compiler.err.preview.feature.disabled",           //NOI18N  
-            "compiler.err.preview.feature.disabled.plural")); // NOI18N
+            "compiler.err.preview.feature.disabled.plural",    // NOI18N
+            "compiler.err.is.preview"));                       // NOI18N
     private static final String ENABLE_PREVIEW_FLAG = "--enable-preview";   // NOI18N
     private static final String SOURCE_FLAG = "--source";   // NOI18N
 
diff --git a/java/maven.hints/src/org/netbeans/modules/maven/hints/errors/EnablePreviewMavenProj.java b/java/maven.hints/src/org/netbeans/modules/maven/hints/errors/EnablePreviewMavenProj.java
index c4dc612..500c581 100644
--- a/java/maven.hints/src/org/netbeans/modules/maven/hints/errors/EnablePreviewMavenProj.java
+++ b/java/maven.hints/src/org/netbeans/modules/maven/hints/errors/EnablePreviewMavenProj.java
@@ -61,14 +61,15 @@
  */
 public class EnablePreviewMavenProj implements ErrorRule<Void> {
 
-    private static final Set<String> ERROR_CODES = new HashSet<String>(Arrays.asList(
-            "compiler.err.preview.feature.disabled",
-            "compiler.err.preview.feature.disabled.plural")); // NOI18N
+    private static final Set<String> ERROR_CODES = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(
+            "compiler.err.preview.feature.disabled",           // NOI18N
+            "compiler.err.preview.feature.disabled.plural",    // NOI18N
+            "compiler.err.is.preview")));                      // NOI18N
     private static final String ENABLE_PREVIEW_FLAG = "--enable-preview";   // NOI18N
 
     @Override
     public Set<String> getCodes() {
-        return Collections.unmodifiableSet(ERROR_CODES);
+        return ERROR_CODES;
     }
 
     @Override
@@ -186,7 +187,7 @@
         private static final String MAVEN_COMPILER_ARTIFACT_ID = "maven-compiler-plugin"; // NOI18N
         private static final String COMPILER_ID_PROPERTY = "compilerId"; // NOI18N
         private static final String COMPILER_ARG = "compilerArgs"; // NOI18N
-        private static final String MAVEN_COMPILER_VERSION = "3.3"; // NOI18N
+        private static final String MAVEN_COMPILER_VERSION = "3.11.0"; // NOI18N
         private static final String ARG = "arg";// NOI18N
         private POMComponentFactory factory;