diff --git a/builtins/src/main/java/org/jline/builtins/Commands.java b/builtins/src/main/java/org/jline/builtins/Commands.java
index 6ab5d84ad..23a068394 100644
--- a/builtins/src/main/java/org/jline/builtins/Commands.java
+++ b/builtins/src/main/java/org/jline/builtins/Commands.java
@@ -240,13 +240,13 @@ public static void history(LineReader reader, PrintStream out, PrintStream err,
         } else if (opt.isSet("save")) {
             history.save();
         } else if (opt.isSet("A")) {
-            Path file = opt.args().size() > 0 ? currentDir.resolve(opt.args().get(0)) : null;
+            Path file = !opt.args().isEmpty() ? currentDir.resolve(opt.args().get(0)) : null;
             history.append(file, increment);
         } else if (opt.isSet("R")) {
-            Path file = opt.args().size() > 0 ? currentDir.resolve(opt.args().get(0)) : null;
+            Path file = !opt.args().isEmpty() ? currentDir.resolve(opt.args().get(0)) : null;
             history.read(file, increment);
         } else if (opt.isSet("W")) {
-            Path file = opt.args().size() > 0 ? currentDir.resolve(opt.args().get(0)) : null;
+            Path file = !opt.args().isEmpty() ? currentDir.resolve(opt.args().get(0)) : null;
             history.write(file, increment);
         } else {
             done = false;
@@ -361,7 +361,7 @@ public ReExecute(History history, Options opt) throws IOException {
                 if (edit) {
                     cmdFile = File.createTempFile("jline-history-", null);
                     cmdWriter = new FileWriter(cmdFile);
-                } else if (opt.args().size() > 0) {
+                } else if (!opt.args().isEmpty()) {
                     String[] s = opt.args().get(argId).split("=");
                     if (s.length == 2) {
                         argId = argId + 1;
@@ -640,7 +640,7 @@ public static void keymap(LineReader reader, PrintStream out, PrintStream err, S
         if (opt.isSet("l")) {
             boolean commands = opt.isSet("L");
             // TODO: handle commands
-            if (opt.args().size() > 0) {
+            if (!opt.args().isEmpty()) {
                 for (String arg : opt.args()) {
                     KeyMap<Binding> map = keyMaps.get(arg);
                     if (map == null) {
@@ -704,7 +704,7 @@ public static void keymap(LineReader reader, PrintStream out, PrintStream err, S
                 err.println("keymap: keymap can not be selected with -N");
                 return;
             }
-            if (opt.args().size() > 0) {
+            if (!opt.args().isEmpty()) {
                 err.println("keymap: too many arguments for -d");
                 return;
             }
@@ -869,9 +869,9 @@ public static void keymap(LineReader reader, PrintStream out, PrintStream err, S
                 err.println("keymap: option -p requires a prefix string");
                 return;
             }
-            if (opt.args().size() > 0 || !opt.isSet("e") && !opt.isSet("v")) {
+            if (!opt.args().isEmpty() || !opt.isSet("e") && !opt.isSet("v")) {
                 Map<String, Binding> bound = map.getBoundKeys();
-                String seq = opt.args().size() > 0 ? KeyMap.translate(opt.args().get(0)) : null;
+                String seq = !opt.args().isEmpty() ? KeyMap.translate(opt.args().get(0)) : null;
                 Map.Entry<String, Binding> begin = null;
                 String last = null;
                 Iterator<Entry<String, Binding>> iterator = bound.entrySet().iterator();
diff --git a/builtins/src/main/java/org/jline/builtins/Nano.java b/builtins/src/main/java/org/jline/builtins/Nano.java
index bfa231d8d..d278bdc8f 100644
--- a/builtins/src/main/java/org/jline/builtins/Nano.java
+++ b/builtins/src/main/java/org/jline/builtins/Nano.java
@@ -1450,7 +1450,7 @@ public String up(String hint) {
                 }
                 boolean found = false;
                 for (int pid = patternId; pid < patterns.size(); pid++) {
-                    if (hint.length() == 0 || patterns.get(pid).startsWith(hint)) {
+                    if (hint.isEmpty() || patterns.get(pid).startsWith(hint)) {
                         patternId = pid + 1;
                         out = patterns.get(pid);
                         found = true;
@@ -1467,7 +1467,7 @@ public String up(String hint) {
 
         public String down(String hint) {
             String out = hint;
-            if (patterns.size() > 0) {
+            if (!patterns.isEmpty()) {
                 if (lastMoveUp) {
                     patternId--;
                 }
@@ -1493,7 +1493,7 @@ public String down(String hint) {
         }
 
         public void add(String pattern) {
-            if (pattern.trim().length() == 0) {
+            if (pattern.trim().isEmpty()) {
                 return;
             }
             patterns.remove(pattern);
@@ -1512,7 +1512,7 @@ public void persist() {
                 try (BufferedWriter writer = Files.newBufferedWriter(
                         historyFile.toAbsolutePath(), StandardOpenOption.WRITE, StandardOpenOption.CREATE)) {
                     for (String s : patterns) {
-                        if (s.trim().length() > 0) {
+                        if (!s.trim().isEmpty()) {
                             writer.append(s);
                             writer.newLine();
                         }
@@ -2151,7 +2151,7 @@ private boolean save(String name) throws IOException {
             setMessage("Wrote " + buffer.lines.size() + " lines");
             return true;
         } catch (IOException e) {
-            setMessage("Error writing " + name + ": " + e.toString());
+            setMessage("Error writing " + name + ": " + e);
             return false;
         } finally {
             Files.deleteIfExists(t);
@@ -2312,7 +2312,7 @@ private String getReadMessage() {
         return sb.toString();
     }
 
-    void gotoLine() throws IOException {
+    void gotoLine() {
         KeyMap<Operation> readKeyMap = new KeyMap<>();
         readKeyMap.setUnicode(Operation.INSERT);
         for (char i = 32; i < 256; i++) {
@@ -2786,12 +2786,7 @@ String replace() throws IOException {
                         if (editBuffer.length() > 0) {
                             replaceTerm = editBuffer.toString();
                         }
-                        if (replaceTerm == null) {
-                            setMessage("Cancelled");
-                            throw new IllegalArgumentException();
-                        } else {
-                            patternHistory.add(replaceTerm);
-                        }
+                        patternHistory.add(replaceTerm);
                         return replaceTerm;
                     case HELP:
                         help("nano-replace-help.txt");
@@ -2965,7 +2960,7 @@ void smoothScrolling() {
         setMessage("Smooth scrolling " + (smoothScrolling ? "enabled" : "disabled"));
     }
 
-    void mouseSupport() throws IOException {
+    void mouseSupport() {
         mouseSupport = !mouseSupport;
         setMessage("Mouse support " + (mouseSupport ? "enabled" : "disabled"));
         terminal.trackMouse(mouseSupport ? Terminal.MouseTracking.Normal : Terminal.MouseTracking.Off);
diff --git a/demo/src/main/java/org/jline/demo/Repl.java b/demo/src/main/java/org/jline/demo/Repl.java
index 362e0bd06..895aee212 100644
--- a/demo/src/main/java/org/jline/demo/Repl.java
+++ b/demo/src/main/java/org/jline/demo/Repl.java
@@ -62,6 +62,7 @@
  */
 public class Repl {
 
+    @SuppressWarnings("resource")
     protected static class MyCommands extends JlineCommandRegistry implements CommandRegistry {
         private LineReader reader;
         private final Supplier<Path> workDir;
@@ -95,7 +96,7 @@ private void tput(CommandInput input) {
             try {
                 Options opt = parseOptions(usage, input.xargs());
                 List<String> argv = opt.args();
-                if (argv.size() > 0) {
+                if (!argv.isEmpty()) {
                     Capability vcap = Capability.byName(argv.get(0));
                     if (vcap != null) {
                         terminal()
@@ -161,7 +162,7 @@ private void echo(CommandInput input) {
                 List<String> argv = opt.args();
                 if (opt.isSet("version")) {
                     terminal().writer().println("echo version: v0.1");
-                } else if (opt.args().size() >= 1) {
+                } else if (!opt.args().isEmpty()) {
                     terminal().writer().println(String.join(" ", opt.args()));
                 }
             } catch (Exception e) {