use io.File#exists instead of nio.Files#exists due to poor performance with jdk 8

https://rules.sonarsource.com/java/RSPEC-3725
https://bugs.openjdk.java.net/browse/JDK-8153414
https://bugs.openjdk.java.net/browse/JDK-8154077

java/execution/impl/src/com/intellij/execution/testDiscovery/TestDiscoveryIndex.java

@@ -14,7 +14,6 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Collection;
 import java.util.Collections;
@@ -37,7 +36,7 @@ public class TestDiscoveryIndex implements Disposable {
   public TestDiscoveryIndex(final Project project, @NotNull Path basePath) {
     myBasePath = basePath;
 
-    if (Files.exists(basePath)) {
+    if (basePath.toFile().exists()) {
       StartupManager.getInstance(project).registerPostStartupActivity(() -> ApplicationManager.getApplication().executeOnPooledThread(() -> {
         getHolder(); // proactively init with maybe io costly compact
       }));

jps/model-serialization/src/org/jetbrains/jps/model/serialization/JpsProjectLoader.java

@@ -308,7 +308,7 @@ public class JpsProjectLoader extends JpsLoaderBase {
     }
 
     Set<String> unloadedModules = new HashSet<>();
-    if (!myLoadUnloadedModules && Files.exists(workspaceFile)) {
+    if (!myLoadUnloadedModules && workspaceFile.toFile().exists()) {
       Element unloadedModulesList = JDomSerializationUtil.findComponent(loadRootElement(workspaceFile), "UnloadedModulesList");
       for (Element element : JDOMUtil.getChildren(unloadedModulesList, "module")) {
         unloadedModules.add(element.getAttributeValue("name"));

platform/build-scripts/icons/src/org/jetbrains/intellij/build/images/IconsClassGenerator.kt

@@ -81,7 +81,7 @@ class IconsClassGenerator(private val projectHome: File, val util: JpsModule, pr
       outFile = targetRoot.resolve("$className.java")
     }
 
-    val oldText = if (Files.exists(outFile)) Files.readAllBytes(outFile).toString(StandardCharsets.UTF_8) else null
+    val oldText = if (outFile.toFile().exists()) Files.readAllBytes(outFile).toString(StandardCharsets.UTF_8) else null
     val newText = generate(module, className, packageName, customLoad, getCopyrightComment(oldText))
 
     val oldLines = oldText?.lines() ?: emptyList()
@@ -309,7 +309,7 @@ class IconsClassGenerator(private val projectHome: File, val util: JpsModule, pr
       assert(isIcon(imageFile)) { "Overriding icon should be valid: $iconName - $imageFile" }
     }
 
-    val size = if (Files.exists(imageFile)) imageSize(imageFile) else null
+    val size = if (imageFile.toFile().exists()) imageSize(imageFile) else null
     val comment: String
     when {
       size != null -> comment = " // ${size.width}x${size.height}"

platform/build-scripts/icons/src/org/jetbrains/intellij/build/images/ImageCollector.kt

@@ -88,9 +88,7 @@ internal class ImageCollector(private val projectHome: Path, private val iconsOn
 
   private fun processRoot(sourceRoot: JpsModuleSourceRoot) {
     val root = Paths.get(JpsPathUtil.urlToPath(sourceRoot.url))
-    if (!Files.exists(root)) {
-      return
-    }
+    if (!root.toFile().exists()) return
 
     val answer = downToRoot(root, root, null, IconRobotsData(), 0)
     val iconsRoot = (if (answer == null || Files.isDirectory(answer)) answer else answer.parent) ?: return
@@ -231,7 +229,7 @@ internal class ImageCollector(private val projectHome: Path, private val iconsOn
 
     fun fork(dir: Path, root: Path): IconRobotsData {
       val robots = dir.resolve(ROBOTS_FILE_NAME)
-      if (!Files.exists(robots)) {
+      if (!robots.toFile().exists()) {
         return this
       }
 

platform/projectModel-api/src/com/intellij/util/io/path.kt

@@ -12,7 +12,7 @@ import java.nio.file.attribute.BasicFileAttributes
 import java.nio.file.attribute.FileTime
 import java.util.*
 
-fun Path.exists(): Boolean = Files.exists(this)
+fun Path.exists(): Boolean = this.toFile().exists()
 
 fun Path.createDirectories(): Path {
   // symlink or existing regular file - Java SDK do this check, but with as `isDirectory(dir, LinkOption.NOFOLLOW_LINKS)`, i.e. links are not checked

platform/testFramework/src/com/intellij/testFramework/rules/TempDirectory.java

@@ -68,7 +68,7 @@ public class TempDirectory extends TemporaryFolder {
   @Override
   public File newFolder(String directoryName) throws IOException {
     Path dir = Paths.get(getRoot().getPath(), directoryName);
-    if (Files.exists(dir)) throw new IOException("Already exists: " + dir);
+    if (dir.toFile().exists()) throw new IOException("Already exists: " + dir);
     Files.createDirectories(dir);
     return dir.toFile();
   }
@@ -77,7 +77,7 @@ public class TempDirectory extends TemporaryFolder {
   @Override
   public File newFile(String fileName) throws IOException {
     Path file = Paths.get(getRoot().getPath(), fileName);
-    if (Files.exists(file)) throw new IOException("Already exists: " + file);
+    if (file.toFile().exists()) throw new IOException("Already exists: " + file);
     makeDirectories(file.getParent());
     Files.createFile(file);
     return file.toFile();