MINOR: Small cleanups in Connect (#15128)

Reviewers: Divij Vaidya <diviv@amazon.com>

connect/basic-auth-extension/src/main/java/org/apache/kafka/connect/rest/basic/auth/extension/BasicAuthSecurityRestExtension.java

@@ -25,7 +25,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.security.auth.login.Configuration;
-import java.io.IOException;
 import java.util.Map;
 import java.util.function.Supplier;
 
@@ -100,7 +99,7 @@ public class BasicAuthSecurityRestExtension implements ConnectRestExtension {
     }
 
     @Override
-    public void close() throws IOException {
+    public void close() {
 
     }
 

connect/basic-auth-extension/src/main/java/org/apache/kafka/connect/rest/basic/auth/extension/JaasBasicAuthFilter.java

@@ -34,7 +34,6 @@ import org.apache.kafka.connect.errors.ConnectException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 
@@ -42,7 +41,6 @@ import javax.security.auth.callback.Callback;
 import javax.security.auth.callback.CallbackHandler;
 import javax.security.auth.callback.NameCallback;
 import javax.security.auth.callback.PasswordCallback;
-import javax.security.auth.callback.UnsupportedCallbackException;
 import javax.security.auth.login.LoginContext;
 import javax.security.auth.login.LoginException;
 import javax.ws.rs.Priorities;
@@ -87,7 +85,7 @@ public class JaasBasicAuthFilter implements ContainerRequestFilter {
     }
 
     @Override
-    public void filter(ContainerRequestContext requestContext) throws IOException {
+    public void filter(ContainerRequestContext requestContext) {
         if (isInternalRequest(requestContext)) {
             log.trace("Skipping authentication for internal request");
             return;
@@ -119,8 +117,8 @@ public class JaasBasicAuthFilter implements ContainerRequestFilter {
 
     public static class BasicAuthCallBackHandler implements CallbackHandler {
 
-        private String username;
+        private final String username;
-        private String password;
+        private final String password;
 
         public BasicAuthCallBackHandler(BasicAuthCredentials credentials) {
             username = credentials.username();
@@ -128,7 +126,7 @@ public class JaasBasicAuthFilter implements ContainerRequestFilter {
         }
 
         @Override
-        public void handle(Callback[] callbacks) throws UnsupportedCallbackException {
+        public void handle(Callback[] callbacks) {
             List<Callback> unsupportedCallbacks = new ArrayList<>();
             for (Callback callback : callbacks) {
                 if (callback instanceof NameCallback) {

connect/basic-auth-extension/src/main/java/org/apache/kafka/connect/rest/basic/auth/extension/PropertyFileLoginModule.java

@@ -54,7 +54,7 @@ public class PropertyFileLoginModule implements LoginModule {
     private String fileName;
     private boolean authenticated;
 
-    private static Map<String, Properties> credentialPropertiesMap = new ConcurrentHashMap<>();
+    private static final Map<String, Properties> CREDENTIAL_PROPERTIES = new ConcurrentHashMap<>();
 
     @Override
     public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState, Map<String, ?> options) {
@@ -64,7 +64,7 @@ public class PropertyFileLoginModule implements LoginModule {
             throw new ConfigException("Property Credentials file must be specified");
         }
 
-        if (!credentialPropertiesMap.containsKey(fileName)) {
+        if (!CREDENTIAL_PROPERTIES.containsKey(fileName)) {
             log.trace("Opening credential properties file '{}'", fileName);
             Properties credentialProperties = new Properties();
             try {
@@ -72,7 +72,7 @@ public class PropertyFileLoginModule implements LoginModule {
                     log.trace("Parsing credential properties file '{}'", fileName);
                     credentialProperties.load(inputStream);
                 }
-                credentialPropertiesMap.putIfAbsent(fileName, credentialProperties);
+                CREDENTIAL_PROPERTIES.putIfAbsent(fileName, credentialProperties);
                 if (credentialProperties.isEmpty())
                     log.warn("Credential properties file '{}' is empty; all requests will be permitted",
                         fileName);
@@ -101,7 +101,7 @@ public class PropertyFileLoginModule implements LoginModule {
         String username = ((NameCallback) callbacks[0]).getName();
         char[] passwordChars = ((PasswordCallback) callbacks[1]).getPassword();
         String password = passwordChars != null ? new String(passwordChars) : null;
-        Properties credentialProperties = credentialPropertiesMap.get(fileName);
+        Properties credentialProperties = CREDENTIAL_PROPERTIES.get(fileName);
 
         if (credentialProperties.isEmpty()) {
             log.trace("Not validating credentials for user '{}' as credential properties file '{}' is empty",
@@ -132,17 +132,17 @@ public class PropertyFileLoginModule implements LoginModule {
     }
 
     @Override
-    public boolean commit() throws LoginException {
+    public boolean commit() {
         return authenticated;
     }
 
     @Override
-    public boolean abort() throws LoginException {
+    public boolean abort() {
         return true;
     }
 
     @Override
-    public boolean logout() throws LoginException {
+    public boolean logout() {
         return true;
     }
 

connect/basic-auth-extension/src/test/java/org/apache/kafka/connect/rest/basic/auth/extension/JaasBasicAuthFilterTest.java

@@ -131,7 +131,7 @@ public class JaasBasicAuthFilterTest {
     }
 
     @Test
-    public void testUnknownCredentialsFile() throws IOException {
+    public void testUnknownCredentialsFile() {
         JaasBasicAuthFilter jaasBasicAuthFilter = setupJaasFilter("KafkaConnect", "/tmp/testcrednetial");
         ContainerRequestContext requestContext = setMock("Basic", "user", "password");
         jaasBasicAuthFilter.filter(requestContext);
@@ -142,7 +142,7 @@ public class JaasBasicAuthFilterTest {
     }
 
     @Test
-    public void testNoFileOption() throws IOException {
+    public void testNoFileOption() {
         JaasBasicAuthFilter jaasBasicAuthFilter = setupJaasFilter("KafkaConnect", null);
         ContainerRequestContext requestContext = setMock("Basic", "user", "password");
         jaasBasicAuthFilter.filter(requestContext);

connect/file/src/test/java/org/apache/kafka/connect/file/FileStreamSinkTaskTest.java

@@ -40,7 +40,6 @@ public class FileStreamSinkTaskTest {
 
     private FileStreamSinkTask task;
     private ByteArrayOutputStream os;
-    private PrintStream printStream;
 
     @TempDir
     public Path topDir;
@@ -49,7 +48,7 @@ public class FileStreamSinkTaskTest {
     @BeforeEach
     public void setup() {
         os = new ByteArrayOutputStream();
-        printStream = new PrintStream(os);
+        PrintStream printStream = new PrintStream(os);
         task = new FileStreamSinkTask(printStream);
         outputFile = topDir.resolve("connect.output").toAbsolutePath().toString();
     }