[PECO-2005] Logging improvements (#538)

Author: jayantsing-db

src/main/java/com/databricks/client/jdbc/DataSource.java

@@ -20,6 +20,7 @@
 public class DataSource implements javax.sql.DataSource, ConnectionPoolDataSource {
 
   private static final JdbcLogger LOGGER = JdbcLoggerFactory.getLogger(DataSource.class);
+  private String user = DEFAULT_USERNAME;
   private String host;
   private int port;
   private String httpPath;
@@ -124,12 +125,11 @@ public String getUrl() {
   }
 
   public String getUsername() {
-    LOGGER.warn(USERNAME_ERROR);
-    return DEFAULT_USERNAME;
+    return user;
   }
 
-  public void setUsername(String username) {
-    LOGGER.warn(USERNAME_ERROR);
+  public void setUsername(String user) {
+    this.user = user;
   }
 
   public String getPassword() {

src/main/java/com/databricks/jdbc/common/DatabricksJdbcConstants.java

@@ -126,6 +126,4 @@ public enum FakeServiceType {
       Pattern.compile("^(\\s*\\()*\\s*LIST", Pattern.CASE_INSENSITIVE);
   public static final String DEFAULT_USERNAME =
       "token"; // This is for PAT. We do not support Basic Auth.
-  public static final String USERNAME_ERROR =
-      "Username authentication is no longer supported.\n Please use OAuth or access token instead.\n See https://docs.databricks.com/en/integrations/jdbc/oss.html#authenticate-the-driver";
 }

src/main/java/com/databricks/jdbc/log/JulLogger.java

@@ -130,11 +130,20 @@ public static synchronized void initLogger(
       Logger jdbcJulLogger = Logger.getLogger(PARENT_CLASS_PREFIX);
 
       jdbcJulLogger.setLevel(level);
+      jdbcJulLogger.setUseParentHandlers(false);
 
       String logPattern = getLogPattern(logDir);
       Handler handler;
       if (logPattern.equalsIgnoreCase(STDOUT)) {
-        handler = new ConsoleHandler();
+        handler =
+            new StreamHandler(System.out, new Slf4jFormatter()) {
+              @Override
+              public void publish(LogRecord record) {
+                super.publish(record);
+                // prompt flushing; full send >>> 🚀
+                flush();
+              }
+            };
       } else {
         handler = new FileHandler(logPattern, logFileSizeBytes, logFileCount, true);
       }

src/test/java/com/databricks/jdbc/log/JulLoggerTest.java

@@ -107,7 +107,7 @@ void testInitLoggerWithStdout() throws IOException {
     JulLogger.initLogger(Level.INFO, JulLogger.STDOUT, 1024, 1);
     Logger jdbcLogger = Logger.getLogger(JulLogger.PARENT_CLASS_PREFIX);
     assertEquals(Level.INFO, jdbcLogger.getLevel());
-    assertInstanceOf(ConsoleHandler.class, jdbcLogger.getHandlers()[0]);
+    assertInstanceOf(StreamHandler.class, jdbcLogger.getHandlers()[0]);
   }
 
   @Test