diff --git a/cli/src/main/java/hudson/cli/CLIConnectionFactory.java b/cli/src/main/java/hudson/cli/CLIConnectionFactory.java
index eceff79eff3c..0553dd215de5 100644
--- a/cli/src/main/java/hudson/cli/CLIConnectionFactory.java
+++ b/cli/src/main/java/hudson/cli/CLIConnectionFactory.java
@@ -1,5 +1,6 @@
 package hudson.cli;
 
+import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 
 /**
@@ -33,7 +34,7 @@ public CLIConnectionFactory basicAuth(String username, String password) {
      * Cf. {@code BasicHeaderApiTokenAuthenticator}.
      */
     public CLIConnectionFactory basicAuth(String userInfo) {
-        return authorization("Basic " + Base64.getEncoder().encodeToString(userInfo.getBytes()));
+        return authorization("Basic " + Base64.getEncoder().encodeToString(userInfo.getBytes(StandardCharsets.UTF_8)));
     }
 
     /**
diff --git a/cli/src/main/java/hudson/cli/PrivateKeyProvider.java b/cli/src/main/java/hudson/cli/PrivateKeyProvider.java
index 1ab1eff33049..f283053f9cb5 100644
--- a/cli/src/main/java/hudson/cli/PrivateKeyProvider.java
+++ b/cli/src/main/java/hudson/cli/PrivateKeyProvider.java
@@ -23,7 +23,6 @@
  */
 package hudson.cli;
 
-import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.logging.Level.FINE;
 
 import java.io.ByteArrayInputStream;
@@ -32,6 +31,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.nio.file.Paths;
@@ -134,7 +134,7 @@ private static String readPemFile(File f) throws IOException{
              DataInputStream dis = new DataInputStream(is)) {
             byte[] bytes = new byte[(int) f.length()];
             dis.readFully(bytes);
-            return new String(bytes);
+            return new String(bytes, StandardCharsets.UTF_8);
         } catch (InvalidPathException e) {
             throw new IOException(e);
         }
@@ -143,7 +143,7 @@ private static String readPemFile(File f) throws IOException{
     public static KeyPair loadKey(String pemString, String passwd) throws IOException, GeneralSecurityException {
         Iterable<KeyPair> itr = SecurityUtils.loadKeyPairIdentities(null,
                 new PathResource(Paths.get("key")),
-                new ByteArrayInputStream(pemString.getBytes(UTF_8)),
+                new ByteArrayInputStream(pemString.getBytes(StandardCharsets.UTF_8)),
                 FilePasswordProvider.of(passwd));
         long numLoaded = itr == null ? 0 : StreamSupport.stream(itr.spliterator(), false).count();
         if (numLoaded <= 0) {
diff --git a/core/src/main/java/hudson/FilePath.java b/core/src/main/java/hudson/FilePath.java
index 16e060f9d23c..cadb8cc257e9 100644
--- a/core/src/main/java/hudson/FilePath.java
+++ b/core/src/main/java/hudson/FilePath.java
@@ -86,6 +86,7 @@
 import java.net.URI;
 import java.net.URL;
 import java.net.URLConnection;
+import java.nio.charset.Charset;
 import java.nio.file.FileSystemException;
 import java.nio.file.FileSystems;
 import java.nio.file.Files;
@@ -2279,7 +2280,7 @@ private static class ReadToString extends MasterToSlaveFileCallable<String> {
         private static final long serialVersionUID = 1L;       
         @Override
         public String invoke(File f, VirtualChannel channel) throws IOException, InterruptedException {
-            return new String(Files.readAllBytes(fileToPath(f)));
+            return new String(Files.readAllBytes(fileToPath(f)), Charset.defaultCharset());
         }
     }
 
@@ -2336,7 +2337,7 @@ private static class Write extends MasterToSlaveFileCallable<Void> {
         public Void invoke(File f, VirtualChannel channel) throws IOException {
             mkdirs(f.getParentFile());
             try (OutputStream fos = Files.newOutputStream(fileToPath(f));
-                    Writer w = encoding != null ? new OutputStreamWriter(fos, encoding) : new OutputStreamWriter(fos)) {
+                    Writer w = encoding != null ? new OutputStreamWriter(fos, encoding) : new OutputStreamWriter(fos, Charset.defaultCharset())) {
                 w.write(content);
             }
             return null;
@@ -3611,5 +3612,4 @@ public boolean accept(File file) {
         }
         private static final long serialVersionUID = 1L;
     }
-
 }
diff --git a/core/src/main/java/hudson/Proc.java b/core/src/main/java/hudson/Proc.java
index dd94d2097c39..24cd16552295 100644
--- a/core/src/main/java/hudson/Proc.java
+++ b/core/src/main/java/hudson/Proc.java
@@ -39,6 +39,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.CancellationException;
@@ -354,7 +355,7 @@ public int join() throws InterruptedException, IOException {
 //                    } catch (IOException x) {
 //                        LOGGER.log(Level.FINE,"stderr termination failed",x);
 //                    }
-                    out.write(msg.getBytes());
+                    out.write(msg.getBytes(Charset.defaultCharset()));
                     out.write('\n');
                 }
                 return r;
diff --git a/core/src/main/java/hudson/WebAppMain.java b/core/src/main/java/hudson/WebAppMain.java
index f3becef4932f..b0596a66374d 100644
--- a/core/src/main/java/hudson/WebAppMain.java
+++ b/core/src/main/java/hudson/WebAppMain.java
@@ -50,6 +50,7 @@
 import java.io.OutputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.nio.file.StandardOpenOption;
@@ -293,7 +294,7 @@ public void joinInit() throws InterruptedException {
      */
     private void recordBootAttempt(File home) {
         try (OutputStream o=Files.newOutputStream(BootFailure.getBootFailureFile(home).toPath(), StandardOpenOption.CREATE, StandardOpenOption.APPEND)) {
-            o.write((new Date() + System.getProperty("line.separator", "\n")).getBytes());
+            o.write((new Date() + System.getProperty("line.separator", "\n")).getBytes(Charset.defaultCharset()));
         } catch (IOException | InvalidPathException e) {
             LOGGER.log(WARNING, "Failed to record boot attempts",e);
         }
diff --git a/core/src/main/java/hudson/cli/CLICommand.java b/core/src/main/java/hudson/cli/CLICommand.java
index 198736dc9fca..d27d0b6beff5 100644
--- a/core/src/main/java/hudson/cli/CLICommand.java
+++ b/core/src/main/java/hudson/cli/CLICommand.java
@@ -40,6 +40,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Type;
 import java.nio.charset.Charset;
@@ -404,7 +405,11 @@ protected void printUsage(PrintStream stderr, CmdLineParser p) {
     public final String getSingleLineSummary() {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         getCmdLineParser().printSingleLineUsage(out);
-        return out.toString();
+        try {
+            return out.toString(getClientCharset().name());
+        } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e);
+        }
     }
 
     /**
@@ -414,7 +419,11 @@ public final String getSingleLineSummary() {
     public final String getUsage() {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         getCmdLineParser().printUsage(out);
-        return out.toString();
+        try {
+            return out.toString(getClientCharset().name());
+        } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e);
+        }
     }
 
     /**
@@ -427,7 +436,11 @@ public final String getLongDescription() {
 
         printUsageSummary(ps);
         ps.close();
-        return out.toString();
+        try {
+            return out.toString(getClientCharset().name());
+        } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e);
+        }
     }
 
     /**
@@ -457,7 +470,7 @@ public void setClientCharset(@NonNull Charset encoding) {
         this.encoding = encoding;
     }
 
-    protected @NonNull Charset getClientCharset() throws IOException, InterruptedException {
+    protected @NonNull Charset getClientCharset() {
         if (encoding != null) {
             return encoding;
         }
diff --git a/core/src/main/java/hudson/console/AnnotatedLargeText.java b/core/src/main/java/hudson/console/AnnotatedLargeText.java
index af70227ad1a5..dafff632d305 100644
--- a/core/src/main/java/hudson/console/AnnotatedLargeText.java
+++ b/core/src/main/java/hudson/console/AnnotatedLargeText.java
@@ -186,7 +186,7 @@ public long writeHtmlTo(long start, Writer w) throws IOException {
         oos.close();
         StaplerResponse rsp = Stapler.getCurrentResponse();
         if (rsp!=null)
-            rsp.setHeader("X-ConsoleAnnotator", new String(Base64.getEncoder().encode(baos.toByteArray())));
+            rsp.setHeader("X-ConsoleAnnotator", Base64.getEncoder().encodeToString(baos.toByteArray()));
         return r;
     }
 
diff --git a/core/src/main/java/hudson/console/ConsoleAnnotationOutputStream.java b/core/src/main/java/hudson/console/ConsoleAnnotationOutputStream.java
index 00a84b6f4612..6e70a743d824 100644
--- a/core/src/main/java/hudson/console/ConsoleAnnotationOutputStream.java
+++ b/core/src/main/java/hudson/console/ConsoleAnnotationOutputStream.java
@@ -121,7 +121,7 @@ public ConsoleAnnotator<T> annotate(T context, MarkupText text) {
                     }
                 } catch (IOException | ClassNotFoundException e) {
                     // if we failed to resurrect an annotation, ignore it.
-                    LOGGER.log(Level.FINE, "Failed to resurrect annotation from \"" + StringEscapeUtils.escapeJava(new String(in, next, rest)) + "\"", e);
+                    LOGGER.log(Level.FINE, "Failed to resurrect annotation from \"" + StringEscapeUtils.escapeJava(new String(in, next, rest, Charset.defaultCharset())) + "\"", e);
                 }
 
                 int bytesUsed = rest - b.available(); // bytes consumed by annotations
diff --git a/core/src/main/java/hudson/console/ConsoleNote.java b/core/src/main/java/hudson/console/ConsoleNote.java
index ee7896895dec..62a9349c02c0 100644
--- a/core/src/main/java/hudson/console/ConsoleNote.java
+++ b/core/src/main/java/hudson/console/ConsoleNote.java
@@ -43,6 +43,7 @@
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Base64;
@@ -326,12 +327,12 @@ public static void skip(DataInputStream in) throws IOException {
      * plus a few magic characters.
      */
     @SuppressFBWarnings(value = "MS_PKGPROTECT", justification = "used in several plugins")
-    public static final byte[] PREAMBLE = PREAMBLE_STR.getBytes();
+    public static final byte[] PREAMBLE = PREAMBLE_STR.getBytes(StandardCharsets.UTF_8);
     /**
      * Post amble is the ANSI escape sequence that brings back the echo.
      */
     @SuppressFBWarnings(value = "MS_PKGPROTECT", justification = "used in several plugins")
-    public static final byte[] POSTAMBLE = POSTAMBLE_STR.getBytes();
+    public static final byte[] POSTAMBLE = POSTAMBLE_STR.getBytes(StandardCharsets.UTF_8);
 
     /**
      * Locates the preamble in the given buffer.
diff --git a/core/src/main/java/hudson/model/AbstractBuild.java b/core/src/main/java/hudson/model/AbstractBuild.java
index 0a7f1cb68323..add476c3cea7 100644
--- a/core/src/main/java/hudson/model/AbstractBuild.java
+++ b/core/src/main/java/hudson/model/AbstractBuild.java
@@ -65,6 +65,7 @@
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.lang.ref.WeakReference;
+import java.nio.channels.ClosedByInterruptException;
 import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Collection;
@@ -668,7 +669,7 @@ public void defaultCheckout() throws IOException, InterruptedException {
                     }
                 } catch (AbortException e) {
                     listener.error(e.getMessage());
-                } catch (InterruptedIOException e) {
+                } catch (ClosedByInterruptException | InterruptedIOException e) {
                     throw (InterruptedException)new InterruptedException().initCause(e);
                 } catch (IOException e) {
                     // checkout error not yet reported
diff --git a/core/src/main/java/hudson/model/FileParameterValue.java b/core/src/main/java/hudson/model/FileParameterValue.java
index b3e5c146cd9d..cc9f39faefee 100644
--- a/core/src/main/java/hudson/model/FileParameterValue.java
+++ b/core/src/main/java/hudson/model/FileParameterValue.java
@@ -36,6 +36,7 @@
 import java.io.OutputStream;
 import java.io.UncheckedIOException;
 import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.util.regex.Pattern;
 import jenkins.util.SystemProperties;
@@ -302,7 +303,7 @@ public String getString(String encoding) throws UnsupportedEncodingException {
 
         @Override
         public String getString() {
-            return new String(get());
+            return new String(get(), Charset.defaultCharset());
         }
 
         @Override
diff --git a/core/src/main/java/hudson/model/Run.java b/core/src/main/java/hudson/model/Run.java
index e331a9e0c172..33673abfcdc3 100644
--- a/core/src/main/java/hudson/model/Run.java
+++ b/core/src/main/java/hudson/model/Run.java
@@ -1509,11 +1509,11 @@ public Collection<Fingerprint> getBuildFingerprints() {
     	}
     	
         String message = "No such file: " + logFile;
-    	return new ByteArrayInputStream(charset != null ? message.getBytes(charset) : message.getBytes());
+    	return new ByteArrayInputStream(charset != null ? message.getBytes(charset) : message.getBytes(Charset.defaultCharset()));
     }
    
     public @NonNull Reader getLogReader() throws IOException {
-        if (charset==null)  return new InputStreamReader(getLogInputStream());
+        if (charset==null)  return new InputStreamReader(getLogInputStream(),Charset.defaultCharset());
         else                return new InputStreamReader(getLogInputStream(),charset);
     }
 
diff --git a/core/src/main/java/hudson/model/UpdateCenter.java b/core/src/main/java/hudson/model/UpdateCenter.java
index 081e4e4cc816..e3b0dcb40f77 100644
--- a/core/src/main/java/hudson/model/UpdateCenter.java
+++ b/core/src/main/java/hudson/model/UpdateCenter.java
@@ -68,6 +68,7 @@
 import java.net.URL;
 import java.net.URLConnection;
 import java.net.UnknownHostException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.AtomicMoveNotSupportedException;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
@@ -2025,11 +2026,11 @@ private static VerificationResult verifyChecksums(String expectedDigest, String
         }
 
         if (caseSensitive) {
-            if (MessageDigest.isEqual(expectedDigest.getBytes(), actualDigest.getBytes())) {
+            if (MessageDigest.isEqual(expectedDigest.getBytes(StandardCharsets.US_ASCII), actualDigest.getBytes(StandardCharsets.US_ASCII))) {
                 return VerificationResult.PASS;
             }
         } else {
-            if (MessageDigest.isEqual(expectedDigest.toLowerCase().getBytes(), actualDigest.toLowerCase().getBytes())) {
+            if (MessageDigest.isEqual(expectedDigest.toLowerCase().getBytes(StandardCharsets.US_ASCII), actualDigest.toLowerCase().getBytes(StandardCharsets.US_ASCII))) {
                 return VerificationResult.PASS;
             }
         }
diff --git a/core/src/main/java/hudson/model/UsageStatistics.java b/core/src/main/java/hudson/model/UsageStatistics.java
index bc292db26c36..a62031bfc406 100644
--- a/core/src/main/java/hudson/model/UsageStatistics.java
+++ b/core/src/main/java/hudson/model/UsageStatistics.java
@@ -193,7 +193,7 @@ public String getStatData() throws IOException {
                 o.write(w);
             }
 
-            return new String(Base64.getEncoder().encode(baos.toByteArray()));
+            return Base64.getEncoder().encodeToString(baos.toByteArray());
         } catch (Throwable e) { // the exception could be GeneralSecurityException, InvalidParameterException or any other depending on the security provider you have installed
             LOG.log(Level.INFO, "Usage statistics could not be sent ({0})", e.getMessage());
             LOG.log(Level.FINE, "Error sending usage statistics", e);
diff --git a/core/src/main/java/hudson/scm/SCM.java b/core/src/main/java/hudson/scm/SCM.java
index 7b94b07e7dd5..1e2fdde83ec8 100644
--- a/core/src/main/java/hudson/scm/SCM.java
+++ b/core/src/main/java/hudson/scm/SCM.java
@@ -52,8 +52,10 @@
 import hudson.security.PermissionScope;
 import hudson.tasks.Builder;
 import java.io.File;
-import java.io.FileWriter;
 import java.io.IOException;
+import java.io.Writer;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -739,7 +741,7 @@ protected final boolean createEmptyChangeLog(File changelogFile, BuildListener l
      * @since 1.568
      */
     protected final void createEmptyChangeLog(@NonNull File changelogFile, @NonNull TaskListener listener, @NonNull String rootTag) throws IOException {
-        try (FileWriter w = new FileWriter(changelogFile)) {
+        try (Writer w = Files.newBufferedWriter(Util.fileToPath(changelogFile), Charset.defaultCharset())) {
             w.write("<"+rootTag +"/>");
         }
     }
diff --git a/core/src/main/java/hudson/security/HudsonAuthenticationEntryPoint.java b/core/src/main/java/hudson/security/HudsonAuthenticationEntryPoint.java
index 229c7974b521..3acab22bf065 100644
--- a/core/src/main/java/hudson/security/HudsonAuthenticationEntryPoint.java
+++ b/core/src/main/java/hudson/security/HudsonAuthenticationEntryPoint.java
@@ -31,6 +31,7 @@
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -100,7 +101,7 @@ public void commence(HttpServletRequest req, HttpServletResponse rsp, Authentica
 
             PrintWriter out;
             try {
-                out = new PrintWriter(new OutputStreamWriter(rsp.getOutputStream()));
+                out = new PrintWriter(new OutputStreamWriter(rsp.getOutputStream(), StandardCharsets.UTF_8));
             } catch (IllegalStateException e) {
                 out = rsp.getWriter();
             }
diff --git a/core/src/main/java/hudson/security/csrf/DefaultCrumbIssuer.java b/core/src/main/java/hudson/security/csrf/DefaultCrumbIssuer.java
index e625759f37fd..a5ec4a26ad72 100644
--- a/core/src/main/java/hudson/security/csrf/DefaultCrumbIssuer.java
+++ b/core/src/main/java/hudson/security/csrf/DefaultCrumbIssuer.java
@@ -83,8 +83,8 @@ protected synchronized String issueCrumb(ServletRequest request, String salt) {
                     buffer.append(req.getSession().getId());
                 }
 
-                md.update(buffer.toString().getBytes());
-                return Util.toHexString(md.digest(salt.getBytes()));
+                md.update(buffer.toString().getBytes(StandardCharsets.UTF_8));
+                return Util.toHexString(md.digest(salt.getBytes(StandardCharsets.US_ASCII)));
             }
         }
         return null;
diff --git a/core/src/main/java/hudson/util/BootFailure.java b/core/src/main/java/hudson/util/BootFailure.java
index 23dff92dcd84..0de96ea8bd1b 100644
--- a/core/src/main/java/hudson/util/BootFailure.java
+++ b/core/src/main/java/hudson/util/BootFailure.java
@@ -4,8 +4,10 @@
 import hudson.WebAppMain;
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.InvalidPathException;
 import java.text.DateFormat;
 import java.util.ArrayList;
 import java.util.Date;
@@ -60,7 +62,7 @@ protected List<Date> loadAttempts(File home) {
             File f = getBootFailureFile(home);
             try {
                 if (f.exists()) {
-                    try (BufferedReader failureFileReader = new BufferedReader(new FileReader(f))) {
+                    try (BufferedReader failureFileReader = Files.newBufferedReader(f.toPath(), Charset.defaultCharset())) {
                         String line;
                         DateFormat df = DateFormat.getDateInstance();
                         while ((line=failureFileReader.readLine())!=null) {
@@ -72,7 +74,7 @@ protected List<Date> loadAttempts(File home) {
                         }
                     }
                 }
-            } catch (IOException e) {
+            } catch (IOException | InvalidPathException e) {
                 LOGGER.log(Level.WARNING,"Failed to parse "+f,e);
             } 
         }
diff --git a/core/src/main/java/hudson/util/CompressedFile.java b/core/src/main/java/hudson/util/CompressedFile.java
index 48add2d49f10..648972716144 100644
--- a/core/src/main/java/hudson/util/CompressedFile.java
+++ b/core/src/main/java/hudson/util/CompressedFile.java
@@ -34,6 +34,7 @@
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.Reader;
+import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -101,7 +102,9 @@ public InputStream read() throws IOException {
 
     /**
      * Loads the file content as a string.
+     * @deprecated removed without replacement
      */
+    @Deprecated
     public String loadAsString() throws IOException {
         long sizeGuess;
         if(file.exists())
@@ -115,7 +118,7 @@ public String loadAsString() throws IOException {
         StringBuilder str = new StringBuilder((int)sizeGuess);
 
         try (InputStream is = read();
-             Reader r = new InputStreamReader(is)) {
+             Reader r = new InputStreamReader(is, Charset.defaultCharset())) {
             char[] buf = new char[8192];
             int len;
             while((len=r.read(buf,0,buf.length))>0)
diff --git a/core/src/main/java/hudson/util/ConsistentHash.java b/core/src/main/java/hudson/util/ConsistentHash.java
index 76c7c8b872f3..3a2d983f3c0c 100644
--- a/core/src/main/java/hudson/util/ConsistentHash.java
+++ b/core/src/main/java/hudson/util/ConsistentHash.java
@@ -24,6 +24,7 @@
 package hudson.util;
 
 import hudson.util.Iterators.DuplicateFilterIterator;
+import java.nio.charset.StandardCharsets;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -304,7 +305,7 @@ private synchronized void refreshTable() {
     private int digest(String s) {
         try {
             MessageDigest messageDigest = createMessageDigest();
-            messageDigest.update(s.getBytes());
+            messageDigest.update(s.getBytes(StandardCharsets.UTF_8));
             byte[] digest = messageDigest.digest();
 
             // 16 bytes -> 4 bytes
diff --git a/core/src/main/java/hudson/util/IOUtils.java b/core/src/main/java/hudson/util/IOUtils.java
index c0b92536ea76..e2eab5dd4514 100644
--- a/core/src/main/java/hudson/util/IOUtils.java
+++ b/core/src/main/java/hudson/util/IOUtils.java
@@ -17,6 +17,7 @@
 import java.io.Reader;
 import java.io.StringWriter;
 import java.io.Writer;
+import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.util.Collection;
@@ -148,7 +149,7 @@ public static int mode(File f) throws PosixException {
      */
     public static String readFirstLine(InputStream is, String encoding) throws IOException {
         try (BufferedReader reader = new BufferedReader(
-                encoding == null ? new InputStreamReader(is) : new InputStreamReader(is, encoding))) {
+                encoding == null ? new InputStreamReader(is, Charset.defaultCharset()) : new InputStreamReader(is, encoding))) {
             return reader.readLine();
         }
     }
diff --git a/core/src/main/java/hudson/util/LogTaskListener.java b/core/src/main/java/hudson/util/LogTaskListener.java
index 33b2ca2318ad..7d696ada4632 100644
--- a/core/src/main/java/hudson/util/LogTaskListener.java
+++ b/core/src/main/java/hudson/util/LogTaskListener.java
@@ -31,6 +31,8 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
@@ -86,7 +88,12 @@ public void write(int b) throws IOException {
         @Override
         public void flush() throws IOException {
             if (baos.size() > 0) {
-                LogRecord lr = new LogRecord(level, baos.toString());
+                LogRecord lr;
+                try {
+                    lr = new LogRecord(level, baos.toString(StandardCharsets.UTF_8.name()));
+                } catch (UnsupportedEncodingException e) {
+                    throw new AssertionError(e);
+                }
                 lr.setLoggerName(logger.getName());
                 lr.setSourceClassName(caller.getClassName());
                 lr.setSourceMethodName(caller.getMethodName());
diff --git a/core/src/main/java/hudson/util/ProcessTree.java b/core/src/main/java/hudson/util/ProcessTree.java
index 4344cc4f42f9..f9d140f51ce5 100644
--- a/core/src/main/java/hudson/util/ProcessTree.java
+++ b/core/src/main/java/hudson/util/ProcessTree.java
@@ -50,15 +50,17 @@
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.ObjectStreamException;
 import java.io.RandomAccessFile;
 import java.io.Serializable;
+import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -983,7 +985,7 @@ class LinuxProcess extends UnixProcess {
             LinuxProcess(int pid) throws IOException {
                 super(pid);
 
-                try (BufferedReader r = new BufferedReader(new FileReader(getFile("status")))) {
+                try (BufferedReader r = Files.newBufferedReader(Util.fileToPath(getFile("status")), StandardCharsets.UTF_8)) {
                     String line;
                     while((line=r.readLine())!=null) {
                         line=line.toLowerCase(Locale.ENGLISH);
@@ -1015,7 +1017,7 @@ public synchronized List<String> getArguments() {
                     for (int i = 0; i < cmdline.length; i++) {
                         byte b = cmdline[i];
                         if(b==0) {
-                            arguments.add(new String(cmdline,pos,i-pos));
+                            arguments.add(new String(cmdline,pos,i-pos, StandardCharsets.UTF_8));
                             pos=i+1;
                         }
                     }
@@ -1039,7 +1041,7 @@ public synchronized EnvVars getEnvironmentVariables() {
                     for (int i = 0; i < environ.length; i++) {
                         byte b = environ[i];
                         if(b==0) {
-                            envVars.addLine(new String(environ,pos,i-pos));
+                            envVars.addLine(new String(environ,pos,i-pos, StandardCharsets.UTF_8));
                             pos=i+1;
                         }
                     }
@@ -1345,7 +1347,12 @@ private String readLine(int fd, long addr, String prefix) throws IOException {
                     buf.write(ch);
                     addr++;
                 }
-                String line = buf.toString();
+                String line;
+                try {
+                    line = buf.toString(StandardCharsets.UTF_8.name());
+                } catch (UnsupportedEncodingException e) {
+                    throw new AssertionError(e);
+                }
                 if(LOGGER.isLoggable(FINEST))
                     LOGGER.finest(prefix+" was "+line);
                 return line;
@@ -1616,7 +1623,12 @@ private String readLine(int fd, long addr, String prefix) throws IOException {
                     buf.write(ch);
                     addr++;
                 }
-                String line = buf.toString();
+                String line;
+                try {
+                    line = buf.toString(StandardCharsets.UTF_8.name());
+                } catch (UnsupportedEncodingException e) {
+                    throw new AssertionError(e);
+                }
                 if(LOGGER.isLoggable(FINEST))
                     LOGGER.finest(prefix+" was "+line);
                 return line;
@@ -1779,13 +1791,16 @@ byte peek() {
                             return getByte(offset);
                         }
 
-                        @SuppressFBWarnings(value = "DM_DEFAULT_ENCODING", justification = "TODO needs triage")
                         String readString() {
                             ByteArrayOutputStream baos = new ByteArrayOutputStream();
                             byte ch;
                             while(offset < length && (ch = getByte(offset++))!='\0')
                                 baos.write(ch);
-                            return baos.toString();
+                            try {
+                                return baos.toString(StandardCharsets.UTF_8.name());
+                            } catch (UnsupportedEncodingException e) {
+                                throw new AssertionError(e);
+                            }
                         }
 
                         void skip0() {
@@ -2098,7 +2113,11 @@ private void parse(Memory m, NativeLong size, Consumer<String> consumer) {
                     while ((ch = m.getByte(offset++)) != '\0') {
                         baos.write(ch);
                     }
-                    consumer.accept(baos.toString());
+                    try {
+                        consumer.accept(baos.toString(StandardCharsets.UTF_8.name()));
+                    } catch (UnsupportedEncodingException e) {
+                        throw new AssertionError(e);
+                    }
                     baos.reset();
                 }
             }
diff --git a/core/src/main/java/hudson/util/Scrambler.java b/core/src/main/java/hudson/util/Scrambler.java
index 374a1e9ba21d..283a80347bad 100644
--- a/core/src/main/java/hudson/util/Scrambler.java
+++ b/core/src/main/java/hudson/util/Scrambler.java
@@ -40,7 +40,7 @@ public class Scrambler {
 
     public static String scramble(String secret) {
         if(secret==null)    return null;
-        return new String(Base64.getEncoder().encode(secret.getBytes(StandardCharsets.UTF_8)));
+        return Base64.getEncoder().encodeToString(secret.getBytes(StandardCharsets.UTF_8));
     }
 
     public static String descramble(String scrambled) {
diff --git a/core/src/main/java/hudson/util/Secret.java b/core/src/main/java/hudson/util/Secret.java
index 45385af68e0d..6da075b331a5 100644
--- a/core/src/main/java/hudson/util/Secret.java
+++ b/core/src/main/java/hudson/util/Secret.java
@@ -148,7 +148,7 @@ public String getEncryptedValue() {
             System.arraycopy(iv, 0, payload, pos, iv.length);
             pos+=iv.length;
             System.arraycopy(encrypted, 0, payload, pos, encrypted.length);
-            return "{"+new String(Base64.getEncoder().encode(payload))+"}";
+            return "{" + Base64.getEncoder().encodeToString(payload) + "}";
         } catch (GeneralSecurityException e) {
             throw new Error(e); // impossible
         }
diff --git a/core/src/main/java/jenkins/security/DefaultConfidentialStore.java b/core/src/main/java/jenkins/security/DefaultConfidentialStore.java
index d24bc837dd4a..49513a02ef60 100644
--- a/core/src/main/java/jenkins/security/DefaultConfidentialStore.java
+++ b/core/src/main/java/jenkins/security/DefaultConfidentialStore.java
@@ -8,6 +8,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.security.GeneralSecurityException;
@@ -151,5 +152,5 @@ public byte[] randomBytes(int size) {
         return random;
     }
 
-    private static final byte[] MAGIC = "::::MAGIC::::".getBytes();
+    private static final byte[] MAGIC = "::::MAGIC::::".getBytes(StandardCharsets.US_ASCII);
 }
diff --git a/core/src/main/java/jenkins/slaves/restarter/UnixSlaveRestarter.java b/core/src/main/java/jenkins/slaves/restarter/UnixSlaveRestarter.java
index d0114c85fa8b..8b7aeeefbdf5 100644
--- a/core/src/main/java/jenkins/slaves/restarter/UnixSlaveRestarter.java
+++ b/core/src/main/java/jenkins/slaves/restarter/UnixSlaveRestarter.java
@@ -13,6 +13,7 @@
 import hudson.Extension;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.logging.Logger;
 import jenkins.util.JavaVMArguments;
@@ -107,7 +108,7 @@ private static String resolveSymlink(File link) throws IOException {
 
             byte[] buf = new byte[r];
             m.read(0, buf, 0, r);
-            return new String(buf);
+            return new String(buf, StandardCharsets.UTF_8);
         }
 
         throw new IOException("Failed to readlink " + link);
diff --git a/core/src/main/java/jenkins/util/JSONSignatureValidator.java b/core/src/main/java/jenkins/util/JSONSignatureValidator.java
index 1c932f0dfa22..a6bd08c91a42 100644
--- a/core/src/main/java/jenkins/util/JSONSignatureValidator.java
+++ b/core/src/main/java/jenkins/util/JSONSignatureValidator.java
@@ -241,7 +241,7 @@ private boolean verifySignature(Signature signature, String providedSignature) {
      * Utility method supporting both possible digest formats: Base64 and Hex
      */
     private boolean digestMatches(byte[] digest, String providedDigest) {
-        return providedDigest.equalsIgnoreCase(Hex.encodeHexString(digest)) || providedDigest.equalsIgnoreCase(new String(Base64.getEncoder().encode(digest)));
+        return providedDigest.equalsIgnoreCase(Hex.encodeHexString(digest)) || providedDigest.equalsIgnoreCase(Base64.getEncoder().encodeToString(digest));
     }
 
 
diff --git a/src/spotbugs/spotbugs-excludes.xml b/src/spotbugs/spotbugs-excludes.xml
index 978042fce847..9f5927b041b1 100644
--- a/src/spotbugs/spotbugs-excludes.xml
+++ b/src/spotbugs/spotbugs-excludes.xml
@@ -51,48 +51,16 @@
       <Bug pattern="DM_DEFAULT_ENCODING"/>
       <Or>
         <Class name="hudson.cli.CLICommand"/>
-        <Class name="hudson.cli.CLIConnectionFactory"/>
         <Class name="hudson.cli.GroovyCommand"/>
         <Class name="hudson.cli.GroovyshCommand"/>
         <Class name="hudson.cli.ListChangesCommand"/>
-        <Class name="hudson.cli.PrivateKeyProvider"/>
-        <Class name="hudson.console.AnnotatedLargeText"/>
-        <Class name="hudson.console.ConsoleAnnotationOutputStream"/>
-        <Class name="hudson.console.ConsoleNote"/>
         <Class name="hudson.FilePath$CreateTextTempFile"/>
-        <Class name="hudson.FilePath$ReadToString"/>
-        <Class name="hudson.FilePath$Write"/>
         <Class name="hudson.lifecycle.WindowsServiceLifecycle"/>
-        <Class name="hudson.model.FileParameterValue$FileItemImpl"/>
-        <Class name="hudson.model.Run"/>
-        <Class name="hudson.model.UpdateCenter"/>
-        <Class name="hudson.model.UsageStatistics"/>
-        <Class name="hudson.Proc$LocalProc"/>
-        <Class name="hudson.scm.SCM"/>
-        <Class name="hudson.security.csrf.DefaultCrumbIssuer"/>
-        <Class name="hudson.security.HudsonAuthenticationEntryPoint"/>
-        <Class name="hudson.util.BootFailure"/>
-        <Class name="hudson.util.ByteBuffer"/>
-        <Class name="hudson.util.CompressedFile"/>
-        <Class name="hudson.util.ConsistentHash"/>
-        <Class name="hudson.util.IOUtils"/>
-        <Class name="hudson.util.LogTaskListener$LogOutputStream"/>
-        <Class name="hudson.util.ProcessTree$AIX$AIXProcess"/>
-        <Class name="hudson.util.ProcessTree$FreeBSD$FreeBSDProcess"/>
-        <Class name="hudson.util.ProcessTree$Linux$LinuxProcess"/>
-        <Class name="hudson.util.ProcessTree$Solaris$SolarisProcess"/>
-        <Class name="hudson.util.Scrambler"/>
-        <Class name="hudson.util.Secret"/>
         <Class name="hudson.util.StreamTaskListener"/>
         <Class name="hudson.util.TextFile"/>
-        <Class name="hudson.WebAppMain"/>
         <Class name="jenkins.diagnosis.HsErrPidList"/>
-        <Class name="jenkins.security.DefaultConfidentialStore"/>
         <Class name="jenkins.security.s2m.AdminWhitelistRule"/>
-        <Class name="jenkins.security.s2m.ConfigDirectory"/>
         <Class name="jenkins.slaves.DefaultJnlpSlaveReceiver"/>
-        <Class name="jenkins.slaves.restarter.UnixSlaveRestarter"/>
-        <Class name="jenkins.util.JSONSignatureValidator"/>
       </Or>
     </And>
   </Match>