Fix bugs reported in Discord

j3270/src/main/java/haus/nightmare/j3270/J3270App.java

@@ -1002,8 +1002,72 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
                 "About j3270", JOptionPane.INFORMATION_MESSAGE);
     }
 
+    /**
+     * Configure application logging. When debug is false, disables all logging
+     * to console and file, preventing creation of j3270.log.
+     */
+    public static void configureLogging(boolean debug) {
+        Logger globalRoot = Logger.getLogger("");
+        for (java.util.logging.Handler h : globalRoot.getHandlers()) {
+            globalRoot.removeHandler(h);
+            try {
+                h.close();
+            } catch (Exception ignored) {
+            }
+        }
+
+        if (debug) {
+            Level logLevel = Level.ALL;
+            globalRoot.setLevel(Level.ALL);
+
+            java.util.logging.Filter appFilter = record -> record.getLoggerName() != null &&
+                    (record.getLoggerName().startsWith("haus.nightmare") || record.getLoggerName().startsWith("org.pubvm"));
+
+            ConsoleHandler consoleHandler = new ConsoleHandler();
+            consoleHandler.setLevel(Level.ALL);
+            consoleHandler.setFormatter(new SimpleFormatter());
+            consoleHandler.setFilter(appFilter);
+            globalRoot.addHandler(consoleHandler);
+
+            Logger.getLogger("haus.nightmare").setLevel(Level.ALL);
+            Logger.getLogger("haus.nightmare.j3270").setLevel(Level.ALL);
+            Logger.getLogger("haus.nightmare.lib3270j").setLevel(Level.ALL);
+
+            try {
+                java.util.logging.FileHandler fileHandler = new java.util.logging.FileHandler("j3270.log", 10 * 1024 * 1024, 1, false) {
+                    @Override
+                    public synchronized void publish(java.util.logging.LogRecord record) {
+                        super.publish(record);
+                        flush();
+                    }
+                };
+                fileHandler.setLevel(Level.ALL);
+                fileHandler.setFormatter(new SimpleFormatter());
+                fileHandler.setFilter(appFilter);
+                globalRoot.addHandler(fileHandler);
+                log.info("Logging protocol trace to j3270.log (debug=" + debug + ", level=" + logLevel + ")");
+            } catch (Exception e) {
+                System.err.println("Could not create j3270.log: " + e.getMessage());
+            }
+        } else {
+            globalRoot.setLevel(Level.OFF);
+            for (String pkg : new String[]{"haus.nightmare", "haus.nightmare.j3270", "haus.nightmare.lib3270j", "org.pubvm"}) {
+                Logger l = Logger.getLogger(pkg);
+                l.setLevel(Level.OFF);
+                for (java.util.logging.Handler h : l.getHandlers()) {
+                    l.removeHandler(h);
+                    try {
+                        h.close();
+                    } catch (Exception ignored) {
+                    }
+                }
+            }
+        }
+    }
+
     // ========== Main ==========
 
+
     public static void main(String[] args) {
         boolean debug = false;
         boolean cliTls = false;
@@ -1045,42 +1109,8 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
             }
         }
 
-        Level logLevel = debug ? Level.FINE : Level.INFO;
+        configureLogging(debug);
 
-        Logger globalRoot = Logger.getLogger("");
-        for (java.util.logging.Handler h : globalRoot.getHandlers()) {
-            globalRoot.removeHandler(h);
-        }
-
-        java.util.logging.Filter appFilter = record -> record.getLoggerName() != null &&
-                (record.getLoggerName().startsWith("haus.nightmare") || record.getLoggerName().startsWith("org.pubvm"));
-
-        ConsoleHandler consoleHandler = new ConsoleHandler();
-        consoleHandler.setLevel(Level.ALL);
-        consoleHandler.setFormatter(new SimpleFormatter());
-        consoleHandler.setFilter(appFilter);
-        globalRoot.addHandler(consoleHandler);
-
-        Logger.getLogger("haus.nightmare").setLevel(Level.ALL);
-        Logger.getLogger("haus.nightmare.j3270").setLevel(Level.ALL);
-        Logger.getLogger("haus.nightmare.lib3270j").setLevel(Level.ALL);
-
-        try {
-            java.util.logging.FileHandler fileHandler = new java.util.logging.FileHandler("j3270.log", 10 * 1024 * 1024, 1, false) {
-                @Override
-                public synchronized void publish(java.util.logging.LogRecord record) {
-                    super.publish(record);
-                    flush();
-                }
-            };
-            fileHandler.setLevel(Level.ALL);
-            fileHandler.setFormatter(new SimpleFormatter());
-            fileHandler.setFilter(appFilter);
-            globalRoot.addHandler(fileHandler);
-            log.info("Logging protocol trace to j3270.log (debug=" + debug + ", level=" + logLevel + ")");
-        } catch (Exception e) {
-            System.err.println("Could not create j3270.log: " + e.getMessage());
-        }
 
         if (configFile != null) {
             try {

j3270/src/test/java/haus/nightmare/j3270/LoggingConfigurationTest.java

@@ -0,0 +1,93 @@
+package haus.nightmare.j3270;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.PrintStream;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class LoggingConfigurationTest {
+
+    private PrintStream originalOut;
+    private PrintStream originalErr;
+
+    @BeforeEach
+    public void setUp() {
+        originalOut = System.out;
+        originalErr = System.err;
+    }
+
+    @AfterEach
+    public void tearDown() {
+        System.setOut(originalOut);
+        System.setErr(originalErr);
+        // Ensure all handlers are closed and logging reset
+        J3270App.configureLogging(false);
+    }
+
+    @Test
+    public void testLoggingDisabledWhenDebugFalse() {
+        File logFile = new File("j3270.log");
+        if (logFile.exists()) {
+            logFile.delete();
+        }
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        ByteArrayOutputStream errContent = new ByteArrayOutputStream();
+        System.setOut(new PrintStream(outContent));
+        System.setErr(new PrintStream(errContent));
+
+        J3270App.configureLogging(false);
+
+        // Root logger should have no handlers attached
+        Logger rootLogger = Logger.getLogger("");
+        assertEquals(0, rootLogger.getHandlers().length, "Root logger should have no handlers when debug is disabled");
+        assertEquals(Level.OFF, rootLogger.getLevel(), "Root logger level should be OFF when debug is disabled");
+
+        // Application loggers should be OFF
+        assertEquals(Level.OFF, Logger.getLogger("haus.nightmare").getLevel());
+        assertEquals(Level.OFF, Logger.getLogger("haus.nightmare.j3270").getLevel());
+        assertEquals(Level.OFF, Logger.getLogger("haus.nightmare.lib3270j").getLevel());
+
+        // Emit log records at all levels
+        Logger appLogger = Logger.getLogger("haus.nightmare.j3270.J3270App");
+        appLogger.severe("Test SEVERE message");
+        appLogger.warning("Test WARNING message");
+        appLogger.info("Test INFO message");
+        appLogger.fine("Test FINE message");
+
+        // Verify nothing was written to stdout or stderr
+        assertEquals(0, outContent.size(), "Standard output should be empty when debug is disabled");
+        assertEquals(0, errContent.size(), "Standard error should be empty when debug is disabled");
+
+        // Verify j3270.log was NOT created
+        assertFalse(logFile.exists(), "j3270.log should NOT be created when debug is disabled");
+    }
+
+    @Test
+    public void testLoggingEnabledWhenDebugTrue() {
+        J3270App.configureLogging(true);
+
+        Logger rootLogger = Logger.getLogger("");
+        Handler[] handlers = rootLogger.getHandlers();
+        assertTrue(handlers.length >= 2, "Root logger should have at least ConsoleHandler and FileHandler when debug is enabled");
+
+        assertEquals(Level.ALL, rootLogger.getLevel());
+        assertEquals(Level.ALL, Logger.getLogger("haus.nightmare").getLevel());
+        assertEquals(Level.ALL, Logger.getLogger("haus.nightmare.j3270").getLevel());
+        assertEquals(Level.ALL, Logger.getLogger("haus.nightmare.lib3270j").getLevel());
+
+        File logFile = new File("j3270.log");
+        assertTrue(logFile.exists(), "j3270.log should be created when debug is enabled");
+
+        // Clean up
+        J3270App.configureLogging(false);
+    }
+}