[java] highlight the static initializers in unnamed classes

GitOrigin-RevId: 4552b7d57db98a2f9ddea85a89497fb3fdeac275

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightVisitorImpl.java

@@ -596,6 +596,12 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
     if (!myHolder.hasErrorResults()) {
       add(HighlightClassUtil.checkThingNotAllowedInInterface(initializer, initializer.getContainingClass()));
     }
+    if (!myHolder.hasErrorResults()) {
+      if (initializer.getContainingClass() instanceof PsiUnnamedClass && HighlightingFeature.UNNAMED_CLASSES.isAvailable(initializer)) {
+        add(HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(initializer).descriptionAndTooltip(
+          JavaErrorBundle.message("text.initializers.are.not.allowed.in.unnamed.classes")));
+      }
+    }
   }
 
   @Override

java/java-psi-impl/src/messages/JavaErrorBundle.properties

@@ -576,4 +576,5 @@ error.cannot.infer.pattern.type=Cannot infer pattern type: {0}
 error.extra.semicolons.between.import.statements.not.allowed=Extra semicolons between import statements are not allowed
 error.guard.allowed.after.patterns.only=Guard is allowed after patterns only
 error.unnamed.class.contains.no.main.method=Unnamed class contains no 'main' method
-text.package.statement.not.allowed.for.unnamed.class=Package statement is not allowed for unnamed class
+text.package.statement.not.allowed.for.unnamed.class=Package statement is not allowed for unnamed class
+text.initializers.are.not.allowed.in.unnamed.classes=Initializers are not allowed in unnamed classes

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/unnamedClass/StaticInitializer.java

@@ -0,0 +1,7 @@
+<error descr="Initializers are not allowed in unnamed classes" textAttributesKey="ERRORS_ATTRIBUTES">static {
+
+}</error>
+
+void main() {
+
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/UnnamedClassHighlightingTest.kt

@@ -20,6 +20,10 @@ class UnnamedClassHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
     doTest()
   }
 
+  fun testStaticInitializer() {
+    doTest()
+  }
+
   private fun doTest() {
     myFixture.configureByFile(getTestName(false) + ".java")
     myFixture.checkHighlighting()