chore: Update version of Error Prone lint checker and adjust code to fix errors. (#2182)

This updates the Error Prone lint plugin to the latest version. It also updates the code to fix
all new warnings.

The ErrorProne projects stopped supporting JDK 11. The last version that supports JDK11 was 2.31.0. This PR
disables ErrorProne checks for JDK 8 and JDK 11 builds.

Author: hessjcg

.github/workflows/tests.yml

@@ -31,7 +31,7 @@ jobs:
     strategy:
       matrix:
         os: [macos-latest, windows-latest, ubuntu-latest]
-        java-version: ["8", "11", "17"]
+        java-version: ["8", "11", "17", "24"]
       fail-fast: false
     permissions:
       contents: "read"

core/src/main/java/com/google/cloud/sql/core/CloudSqlInstanceName.java

@@ -96,6 +96,7 @@ public static boolean isValidInstanceName(String connectionName) {
    * @param connectionName instance connection name in the format "PROJECT_ID:REGION_ID:INSTANCE_ID"
    * @param domainName the domain name used to look up the instance, or null.
    */
+  @SuppressWarnings("ExpensiveLenientFormatString")
   CloudSqlInstanceName(String connectionName, String domainName) {
     Matcher matcher = CONNECTION_NAME.matcher(connectionName);
     checkArgument(

core/src/main/java/com/google/cloud/sql/core/JndiDnsResolver.java

@@ -53,7 +53,7 @@ class JndiDnsResolver implements DnsResolver {
    * @throws javax.naming.NameNotFoundException when the domain name did not resolve.
    */
   @Override
-  @SuppressWarnings("JdkObsolete")
+  @SuppressWarnings({"JdkObsolete", "BanJNDI"})
   public Collection<String> resolveTxt(String domainName)
       throws javax.naming.NameNotFoundException {
     try {

core/src/main/java/com/google/cloud/sql/core/RefreshCalculator.java

@@ -30,6 +30,9 @@ class RefreshCalculator {
   // time to complete.
   static final Duration DEFAULT_REFRESH_BUFFER = Duration.ofMinutes(4);
 
+  // Suppressing the warning for toSeconds. getSeconds is in JDK 8. toSeconds was only introduced in
+  // Jdk 1.9
+  @SuppressWarnings("JavaDurationGetSecondsToToSeconds")
   long calculateSecondsUntilNextRefresh(Instant now, Instant expiration) {
     Duration timeUntilExp = Duration.between(now, expiration);
 

core/src/test/java/com/google/cloud/sql/core/ConnectorTest.java

@@ -40,6 +40,7 @@
 import java.time.Instant;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Locale;
 import javax.naming.NameNotFoundException;
 import javax.net.ssl.SSLHandshakeException;
 import org.junit.After;
@@ -111,7 +112,7 @@ public void create_throwsErrorForInvalidTlsCommonNameMismatch()
 
     assertThat(ex)
         .hasMessageThat()
-        .isEqualTo(
+        .contains(
             "Server certificate CN does not match instance name. "
                 + "Server certificate CN=myProject:myInstance "
                 + "Expected instance name: myProject:wrongwrongwrong");
@@ -522,7 +523,7 @@ public void create_successfulPublicCasConnection() throws IOException, Interrupt
   }
 
   private boolean isWindows() {
-    String os = System.getProperty("os.name").toLowerCase();
+    String os = System.getProperty("os.name").toLowerCase(Locale.ROOT);
     return os.contains("win");
   }
 
@@ -943,12 +944,12 @@ private static class MockDnsResolver implements DnsResolver {
     private final String domainName;
     private final String instanceName;
 
-    public MockDnsResolver() {
+    private MockDnsResolver() {
       this.domainName = null;
       this.instanceName = null;
     }
 
-    public MockDnsResolver(String domainName, String instanceName) {
+    private MockDnsResolver(String domainName, String instanceName) {
       this.domainName = domainName;
       this.instanceName = instanceName;
     }
@@ -972,16 +973,16 @@ private static class MutableDnsResolver implements DnsResolver {
     private final String domainName;
     private String instanceName;
 
-    public MutableDnsResolver(String domainName, String instanceName) {
+    private MutableDnsResolver(String domainName, String instanceName) {
       this.domainName = domainName;
       this.instanceName = instanceName;
     }
 
-    public synchronized void setInstanceName(String instanceName) {
+    private synchronized void setInstanceName(String instanceName) {
       this.instanceName = instanceName;
     }
 
-    public synchronized void clearInstanceName() {
+    private synchronized void clearInstanceName() {
       this.instanceName = null;
     }
 

core/src/test/java/com/google/cloud/sql/core/DefaultConnectionInfoRepositoryIntegrationTests.java

@@ -45,8 +45,7 @@ public static void checkEnvVars() {
     requiredEnvVars.forEach(
         (varName) ->
             assertWithMessage(
-                    String.format(
-                        "Environment variable '%s' must be set to perform these tests.", varName))
+                    "Environment variable '%s' must be set to perform these tests.", varName)
                 .that(System.getenv(varName))
                 .isNotEmpty());
   }

core/src/test/java/com/google/cloud/sql/core/FakeUnixSocketServer.java

@@ -16,6 +16,8 @@
 
 package com.google.cloud.sql.core;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.SelectionKey;
@@ -35,7 +37,7 @@
  * https://github.com/jnr/jnr-unixsocket/blob/master/src/test/java/jnr/unixsocket/example/UnixServer.java
  */
 class FakeUnixSocketServer {
-  private static Logger log = LoggerFactory.getLogger(FakeUnixSocketServer.class);
+  private static final Logger log = LoggerFactory.getLogger(FakeUnixSocketServer.class);
   private final String path;
   private final UnixSocketAddress address;
   private UnixServerSocketChannel channel;
@@ -104,24 +106,24 @@ public void run() {
     log.info("UnixServer EXIT");
   }
 
-  static interface Actor {
-    public boolean rxready();
+  interface Actor {
+    boolean rxready();
   }
 
   static final class ServerActor implements Actor {
     private final UnixServerSocketChannel channel;
 
-    public ServerActor(UnixServerSocketChannel channel) {
+    private ServerActor(UnixServerSocketChannel channel) {
       this.channel = channel;
     }
 
     @Override
-    public final boolean rxready() {
+    public boolean rxready() {
       log.info("Handling unix socket connect.");
       try {
         UnixSocketChannel client = channel.accept();
         client.configureBlocking(false);
-        ByteBuffer response = ByteBuffer.wrap("HELLO\n".getBytes("UTF-8"));
+        ByteBuffer response = ByteBuffer.wrap("HELLO\n".getBytes(UTF_8));
         client.write(response);
         log.info("Handling unix socket done.");
         return true;

core/src/test/java/com/google/cloud/sql/core/InstanceCheckingTrustManagerFactoryTest.java

@@ -176,12 +176,12 @@ private static class TestCase {
 
     private final boolean cas;
 
-    public TestCase(
+    private TestCase(
         String desc, String serverName, String icn, String cn, String san, boolean valid) {
       this(desc, serverName, icn, cn, san, valid, false);
     }
 
-    public TestCase(
+    private TestCase(
         String desc,
         String serverName,
         String icn,

core/src/test/java/com/google/cloud/sql/core/MockAdminApi.java

@@ -207,22 +207,22 @@ private static class ConnectSettingsRequest {
     private final ConnectSettings settings;
     private final String baseUrl;
 
-    public ConnectSettingsRequest(
+    private ConnectSettingsRequest(
         CloudSqlInstanceName cloudSqlInstanceName, ConnectSettings settings, String baseUrl) {
       this.cloudSqlInstanceName = cloudSqlInstanceName;
       this.settings = settings;
       this.baseUrl = baseUrl;
     }
 
-    public ConnectSettings getSettings() {
+    private ConnectSettings getSettings() {
       return settings;
     }
 
-    public CloudSqlInstanceName getCloudSqlInstanceName() {
+    private CloudSqlInstanceName getCloudSqlInstanceName() {
       return cloudSqlInstanceName;
     }
 
-    public String getBaseUrl() {
+    private String getBaseUrl() {
       return baseUrl;
     }
   }
@@ -233,7 +233,7 @@ private static class GenerateEphemeralCertRequest {
     private final GenerateEphemeralCertResponse generateEphemeralCertResponse;
     private final String baseUrl;
 
-    public GenerateEphemeralCertRequest(
+    private GenerateEphemeralCertRequest(
         CloudSqlInstanceName instanceConnectionName,
         GenerateEphemeralCertResponse generateEphemeralCertResponse,
         String baseUrl) {
@@ -242,15 +242,15 @@ public GenerateEphemeralCertRequest(
       this.baseUrl = baseUrl;
     }
 
-    public CloudSqlInstanceName getCloudSqlInstanceName() {
+    private CloudSqlInstanceName getCloudSqlInstanceName() {
       return cloudSqlInstanceName;
     }
 
-    public GenerateEphemeralCertResponse getGenerateEphemeralCertResponse() {
+    private GenerateEphemeralCertResponse getGenerateEphemeralCertResponse() {
       return generateEphemeralCertResponse;
     }
 
-    public String getBaseUrl() {
+    private String getBaseUrl() {
       return baseUrl;
     }
   }
@@ -259,7 +259,7 @@ private static class MockRefreshHandler implements OAuth2RefreshHandler {
     private final String refreshToken;
     private final Date expirationTime;
 
-    public MockRefreshHandler(String refreshToken, Date expirationTime) {
+    private MockRefreshHandler(String refreshToken, Date expirationTime) {
       this.refreshToken = refreshToken;
       this.expirationTime = expirationTime;
     }

core/src/test/java/com/google/cloud/sql/core/RefreshCalculatorTest.java

@@ -57,11 +57,11 @@ public RefreshCalculatorTest(String name, Duration input, Duration want) {
     this.refreshCalculator = new RefreshCalculator();
   }
 
-  private static final Instant NOW = Instant.now().truncatedTo(SECONDS);
   private final RefreshCalculator refreshCalculator;
 
   @Test
   public void testDuration() {
+    final Instant NOW = Instant.now().truncatedTo(SECONDS);
     Duration nextRefresh =
         Duration.ofSeconds(
             refreshCalculator.calculateSecondsUntilNextRefresh(NOW, NOW.plus(input)));