diff --git a/java/java-impl/src/com/intellij/codeInspection/reflectiveAccess/JavaReflectionMemberAccessInspection.java b/java/java-impl/src/com/intellij/codeInspection/reflectiveAccess/JavaReflectionMemberAccessInspection.java
index 18b83d0dd04d..3e69e2f1c67f 100644
--- a/java/java-impl/src/com/intellij/codeInspection/reflectiveAccess/JavaReflectionMemberAccessInspection.java
+++ b/java/java-impl/src/com/intellij/codeInspection/reflectiveAccess/JavaReflectionMemberAccessInspection.java
@@ -25,7 +25,6 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 import static com.intellij.psi.CommonClassNames.*;
 import static com.intellij.psi.impl.source.resolve.reference.impl.JavaReflectionReferenceUtil.*;
@@ -95,7 +94,7 @@ public class JavaReflectionMemberAccessInspection extends AbstractBaseJavaLocalI
   }
 
   private void collectSettings() {
-    ignoredClassNamesString = ignoredClassNames.stream().collect(Collectors.joining(","));
+    ignoredClassNamesString = String.join(",", ignoredClassNames);
   }
 
   @NotNull
diff --git a/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaTreeNode.java b/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaTreeNode.java
index dc6f3700206f..76774c4687f8 100644
--- a/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaTreeNode.java
+++ b/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaTreeNode.java
@@ -180,7 +180,7 @@ public class JsonSchemaTreeNode {
       if (mySchema.getRef() != null) sb.append("$ref: ").append(mySchema.getRef()).append("\n");
       else if (!mySchema.getProperties().isEmpty()) {
         sb.append("properties: ");
-        sb.append(mySchema.getProperties().keySet().stream().collect(Collectors.joining(", "))).append("\n");
+        sb.append(String.join(", ", mySchema.getProperties().keySet())).append("\n");
       }
       if (!myChildren.isEmpty()) {
         sb.append("OR children of NODE#").append(hashCode()).append(":\n----------------\n")
diff --git a/platform/lang-impl/src/com/intellij/refactoring/introduce/inplace/OccurrencesChooser.java b/platform/lang-impl/src/com/intellij/refactoring/introduce/inplace/OccurrencesChooser.java
index 688382da8a6e..651f8f50c33c 100644
--- a/platform/lang-impl/src/com/intellij/refactoring/introduce/inplace/OccurrencesChooser.java
+++ b/platform/lang-impl/src/com/intellij/refactoring/introduce/inplace/OccurrencesChooser.java
@@ -31,9 +31,8 @@ import org.jetbrains.annotations.NotNull;
 import javax.swing.*;
 import java.awt.*;
 import java.text.MessageFormat;
-import java.util.*;
 import java.util.List;
-import java.util.stream.Collectors;
+import java.util.*;
 
 // Please do not make this class concrete<PsiElement>.
 // This prevents languages with polyadic expressions or sequences
@@ -119,7 +118,7 @@ public abstract class OccurrencesChooser<T> {
       callback.pass(occurrencesMap.keySet().iterator().next());
       return;
     }
-    List<C> model = occurrencesMap.keySet().stream().collect(Collectors.toList());
+    List<C> model = new ArrayList<>(occurrencesMap.keySet());
 
     JBPopupFactory.getInstance()
       .createPopupChooserBuilder(model)
diff --git a/plugins/javaFX/src/org/jetbrains/plugins/javaFX/sceneBuilder/SceneBuilderEditor.java b/plugins/javaFX/src/org/jetbrains/plugins/javaFX/sceneBuilder/SceneBuilderEditor.java
index fb400736d1c8..b0734f34f175 100644
--- a/plugins/javaFX/src/org/jetbrains/plugins/javaFX/sceneBuilder/SceneBuilderEditor.java
+++ b/plugins/javaFX/src/org/jetbrains/plugins/javaFX/sceneBuilder/SceneBuilderEditor.java
@@ -35,7 +35,6 @@ import java.io.File;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.stream.Collectors;
 
 /**
  * @author Alexander Lobas
@@ -110,7 +109,7 @@ public class SceneBuilderEditor extends UserDataHolderBase implements FileEditor
         }
       }
       Collections.reverse(messages);
-      description = "\n" + messages.stream().collect(Collectors.joining("\n\n"));
+      description = "\n" + String.join("\n\n", messages);
     }
     else {
       description = "Unknown error occurred";
diff --git a/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlMissingKeysInspectionBase.java b/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlMissingKeysInspectionBase.java
index ee04fdaf9abf..1983a3357dfd 100644
--- a/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlMissingKeysInspectionBase.java
+++ b/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlMissingKeysInspectionBase.java
@@ -124,7 +124,7 @@ public abstract class YamlMissingKeysInspectionBase extends YamlMetaTypeInspecti
 
   @NotNull
   private static String composeKeyList(@NotNull final Collection<String> missingKeys) {
-    return missingKeys.stream().collect(Collectors.joining(", "));
+    return String.join(", ", missingKeys);
   }
 
   @NotNull
diff --git a/plugins/yaml/src/org/jetbrains/yaml/meta/model/YamlEnumType.java b/plugins/yaml/src/org/jetbrains/yaml/meta/model/YamlEnumType.java
index 9abd93614888..a74be46ff613 100644
--- a/plugins/yaml/src/org/jetbrains/yaml/meta/model/YamlEnumType.java
+++ b/plugins/yaml/src/org/jetbrains/yaml/meta/model/YamlEnumType.java
@@ -70,12 +70,12 @@ public class YamlEnumType extends YamlScalarType {
     super.validateScalarValue(scalarValue, holder);
 
     String text = scalarValue.getTextValue();
-    if (text.length() == 0) {
+    if (text.isEmpty()) {
       // not our business
       return;
     }
 
-    if (Arrays.stream(myDeprecatedLiterals).anyMatch(text::equals)) {
+    if (Arrays.asList(myDeprecatedLiterals).contains(text)) {
       holder.registerProblem(scalarValue,
                              YAMLBundle.message("YamlEnumType.validation.warning.value.deprecated", text),
                              ProblemHighlightType.LIKE_DEPRECATED);
diff --git a/python/src/com/jetbrains/python/console/PydevConsoleCommunication.java b/python/src/com/jetbrains/python/console/PydevConsoleCommunication.java
index 8d44e7f0cd12..fb8dae6b2e5b 100644
--- a/python/src/com/jetbrains/python/console/PydevConsoleCommunication.java
+++ b/python/src/com/jetbrains/python/console/PydevConsoleCommunication.java
@@ -298,7 +298,7 @@ public abstract class PydevConsoleCommunication extends AbstractConsoleCommunica
 
   @NotNull
   private static PydevCompletionVariant toPydevCompletionVariant(@NotNull CompletionOption option) {
-    String args = option.arguments.stream().collect(Collectors.joining(" "));
+    String args = String.join(" ", option.arguments);
     return new PydevCompletionVariant(option.name, option.documentation, args, option.type.getValue());
   }