KT-38003 works for Java implementations too

idea/src/org/jetbrains/kotlin/idea/slicer/OutflowSlicer.kt

@@ -7,7 +7,9 @@ package org.jetbrains.kotlin.idea.slicer
 
 import com.intellij.codeInsight.highlighting.ReadWriteAccessDetector.Access
 import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiMethod
 import com.intellij.psi.impl.light.LightMemberReference
+import com.intellij.slicer.JavaSliceUsage
 import com.intellij.usageView.UsageInfo
 import org.jetbrains.kotlin.cfg.pseudocode.PseudoValue
 import org.jetbrains.kotlin.cfg.pseudocode.instructions.Instruction
@@ -68,12 +70,21 @@ class OutflowSlicer(
 
             val callable = variable.ownerFunction as? KtCallableDeclaration
             callable?.forEachOverridingElement(scope = analysisScope) { _, overridingMember ->
-                //TODO: Java overriders
-                if (overridingMember is KtCallableDeclaration) {
-                    val parameters = overridingMember.valueParameters
-                    check(parameters.size == callable.valueParameters.size)
-                    val overridingParameter = parameters[variable.parameterIndex()]
-                    overridingParameter.passToProcessor()
+                when (overridingMember) {
+                    is KtCallableDeclaration -> {
+                        val parameters = overridingMember.valueParameters
+                        check(parameters.size == callable.valueParameters.size)
+                        parameters[variable.parameterIndex()].passToProcessor()
+                    }
+
+                    is PsiMethod -> {
+                        val parameters = overridingMember.parameterList.parameters
+                        check(parameters.size == callable.valueParameters.size)
+                        parameters[variable.parameterIndex()].passToProcessor()
+                        processor.process(JavaSliceUsage.createRootUsage(parameters[variable.parameterIndex()], parentUsage.params))
+                    }
+
+                    else -> {} // not supported
                 }
                 true
             }

idea/testData/slicer/outflow/abstractMethodParameter2.java

@@ -0,0 +1,5 @@
+class JavaClass implements I {
+    public void foo(Object p) {
+        System.out.println(p);
+    }
+}

idea/testData/slicer/outflow/abstractMethodParameter2.kt

@@ -6,7 +6,7 @@ interface I {
 
 class C : I {
     override fun foo(p: Any) {
-        println(p)
+        println(p) // this usage will be shown twice due to bug in Java implementation: https://youtrack.jetbrains.com/issue/IDEA-236958
     }
 }
 

idea/testData/slicer/outflow/abstractMethodParameter2.results.txt

@@ -1,4 +1,7 @@
 14 i.foo(<bold>s</bold>)
 4 	fun foo(<bold>p: Any</bold>)
+2 		public void foo(Object <bold>p</bold>) {
+3 			System.out.println(<bold>p</bold>);
+9 			println(<bold>p</bold>) // this usage will be shown twice due to bug in Java implementation: https://youtrack.jetbrains.com/issue/IDEA-236958
 8 		override fun foo(<bold>p: Any</bold>) {
-9 			println(<bold>p</bold>)
+9 			DUPLICATE: println(<bold>p</bold>) // this usage will be shown twice due to bug in Java implementation: https://youtrack.jetbrains.com/issue/IDEA-236958