diff --git a/core/src/main/java/org/apache/commons/fileupload/FileItem.java b/core/src/main/java/org/apache/commons/fileupload/FileItem.java
index 9bf38c5b2..c2a91b692 100644
--- a/core/src/main/java/org/apache/commons/fileupload/FileItem.java
+++ b/core/src/main/java/org/apache/commons/fileupload/FileItem.java
@@ -37,7 +37,7 @@
  * {@code org.apache.commons.fileupload.servlet.ServletFileUpload
  * #parseRequest(javax.servlet.http.HttpServletRequest)}), you may
  * either request all contents of the file at once using {@link #get()} or
- * request an {@link java.io.InputStream InputStream} with
+ * request an {@link InputStream} with
  * {@link #getInputStream()} and process the file without attempting to load
  * it into memory, which may come handy with large files.
  *
@@ -53,10 +53,10 @@ public interface FileItem {
     // ------------------------------- Methods from javax.activation.DataSource
 
     /**
-     * Returns an {@link java.io.InputStream InputStream} that can be
+     * Returns an {@link InputStream} that can be
      * used to retrieve the contents of the file.
      *
-     * @return An {@link java.io.InputStream InputStream} that can be
+     * @return An {@link InputStream} that can be
      *         used to retrieve the contents of the file.
      *
      * @throws IOException if an error occurs.
@@ -195,10 +195,10 @@ public interface FileItem {
     void setFormField(boolean state);
 
     /**
-     * Returns an {@link java.io.OutputStream OutputStream} that can
+     * Returns an {@link OutputStream} that can
      * be used for storing the contents of the file.
      *
-     * @return An {@link java.io.OutputStream OutputStream} that can be used
+     * @return An {@link OutputStream} that can be used
      *         for storing the contensts of the file.
      *
      * @throws IOException if an error occurs.
diff --git a/core/src/main/java/org/kohsuke/stapler/RequestImpl.java b/core/src/main/java/org/kohsuke/stapler/RequestImpl.java
index 53c25f6b2..ffd8ae67e 100644
--- a/core/src/main/java/org/kohsuke/stapler/RequestImpl.java
+++ b/core/src/main/java/org/kohsuke/stapler/RequestImpl.java
@@ -28,6 +28,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.UncheckedIOException;
+import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
@@ -1215,7 +1216,7 @@ public JSONObject getSubmittedForm() throws ServletException {
                         // JENKINS-11543: If client doesn't set charset per part, use request encoding
                         try {
                             p = item.getString(Charset.forName(getCharacterEncoding()));
-                        } catch (java.io.UnsupportedEncodingException uee) {
+                        } catch (UnsupportedEncodingException uee) {
                             LOGGER.log(
                                     Level.WARNING,
                                     "Request has unsupported charset, using default for 'json' parameter",
diff --git a/core/src/main/java/org/kohsuke/stapler/framework/io/WriterOutputStream.java b/core/src/main/java/org/kohsuke/stapler/framework/io/WriterOutputStream.java
index feb98c1af..7f2eec46d 100644
--- a/core/src/main/java/org/kohsuke/stapler/framework/io/WriterOutputStream.java
+++ b/core/src/main/java/org/kohsuke/stapler/framework/io/WriterOutputStream.java
@@ -46,7 +46,7 @@ public class WriterOutputStream extends OutputStream {
     private final Writer writer;
     private final CharsetDecoder decoder;
 
-    private java.nio.ByteBuffer buf = ByteBuffer.allocate(1024);
+    private ByteBuffer buf = ByteBuffer.allocate(1024);
     private CharBuffer out = CharBuffer.allocate(1024);
 
     public WriterOutputStream(Writer out, Charset charset) {
diff --git a/core/src/main/java/org/kohsuke/stapler/interceptor/RequirePOST.java b/core/src/main/java/org/kohsuke/stapler/interceptor/RequirePOST.java
index 152a97869..e439f9aea 100644
--- a/core/src/main/java/org/kohsuke/stapler/interceptor/RequirePOST.java
+++ b/core/src/main/java/org/kohsuke/stapler/interceptor/RequirePOST.java
@@ -41,7 +41,7 @@ interface ErrorCustomizer {
          * Return the {@link ForwardToView} showing a custom error page for {@link RequirePOST} annotated methods. This is
          * typically used to show a form with a "Try again using POST" button.
          *
-         * <p>Implementations are looked up using {@link java.util.ServiceLoader}, the first implementation to return a non-null value will be used.</p>
+         * <p>Implementations are looked up using {@link ServiceLoader}, the first implementation to return a non-null value will be used.</p>
          */
         @CheckForNull
         ForwardToView getForwardView();
diff --git a/core/src/test/java/org/kohsuke/stapler/DispatcherTest.java b/core/src/test/java/org/kohsuke/stapler/DispatcherTest.java
index 8b9031e20..d115508ba 100644
--- a/core/src/test/java/org/kohsuke/stapler/DispatcherTest.java
+++ b/core/src/test/java/org/kohsuke/stapler/DispatcherTest.java
@@ -82,7 +82,7 @@ public void testVerbMatch() throws Exception {
         }
     }
 
-    private void check(WebClient wc, HttpMethod m) throws java.io.IOException {
+    private void check(WebClient wc, HttpMethod m) throws IOException {
         TextPage p = wc.getPage(new WebRequest(new URL(url, "verbMatch/"), m));
         assertEquals("Got " + m.name(), p.getContent());
     }
diff --git a/core/src/test/java/org/kohsuke/stapler/export/XMLDataWriterTest.java b/core/src/test/java/org/kohsuke/stapler/export/XMLDataWriterTest.java
index dada64597..f27643b17 100644
--- a/core/src/test/java/org/kohsuke/stapler/export/XMLDataWriterTest.java
+++ b/core/src/test/java/org/kohsuke/stapler/export/XMLDataWriterTest.java
@@ -49,7 +49,7 @@ public String getName() {
 
         @Exported(visibility = 2)
         public Collection<Action> getActions() {
-            return java.util.Arrays.asList(new ParameterAction(), new CauseAction());
+            return List.of(new ParameterAction(), new CauseAction());
         }
     }