[DOCS] Change "a SSL" to "an SSL" in the Java docs (#46524)

Author: dengziming

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ssl/SSLService.java

@@ -97,7 +97,7 @@ public class SSLService {
     private final Map<String, SSLConfiguration> sslConfigurations;
 
     /**
-     * A mapping from a SSLConfiguration to a pre-built context.
+     * A mapping from an SSLConfiguration to a pre-built context.
      * <p>
      * This is managed separately to the {@link #sslConfigurations} map, so that a single configuration (by object equality)
      * always maps to the same {@link SSLContextHolder}, even if it is being used within a different context-name.
@@ -249,7 +249,7 @@ public SSLEngine createSSLEngine(SSLConfiguration configuration, String host, in
         String[] supportedProtocols = configuration.supportedProtocols().toArray(Strings.EMPTY_ARRAY);
         SSLParameters parameters = new SSLParameters(ciphers, supportedProtocols);
         if (configuration.verificationMode().isHostnameVerificationEnabled() && host != null) {
-            // By default, a SSLEngine will not perform hostname verification. In order to perform hostname verification
+            // By default, an SSLEngine will not perform hostname verification. In order to perform hostname verification
             // we need to specify a EndpointIdentificationAlgorithm. We use the HTTPS algorithm to prevent against
             // man in the middle attacks for all of our connections.
             parameters.setEndpointIdentificationAlgorithm("HTTPS");
@@ -299,7 +299,7 @@ SSLContextHolder sslContextHolder(SSLConfiguration sslConfiguration) {
         Objects.requireNonNull(sslConfiguration, "SSL Configuration cannot be null");
         SSLContextHolder holder = sslContexts.get(sslConfiguration);
         if (holder == null) {
-            throw new IllegalArgumentException("did not find a SSLContext for [" + sslConfiguration.toString() + "]");
+            throw new IllegalArgumentException("did not find an SSLContext for [" + sslConfiguration.toString() + "]");
         }
         return holder;
     }
@@ -632,7 +632,7 @@ static void invalidateSessions(SSLSessionContext sslSessionContext) {
         while (sessionIds.hasMoreElements()) {
             byte[] sessionId = sessionIds.nextElement();
             SSLSession session = sslSessionContext.getSession(sessionId);
-            // a SSLSession could be null as there is no lock while iterating, the session cache
+            // an SSLSession could be null as there is no lock while iterating, the session cache
             // could have evicted a value, the session could be timed out, or the session could
             // have already been invalidated, which removes the value from the session cache in the
             // sun implementation

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ssl/SSLServiceTests.java

@@ -712,7 +712,7 @@ public void testThatSSLContextWithoutSettingsWorks() throws Exception {
         SSLContext sslContext = sslService.sslContext(sslService.sslConfiguration(Settings.EMPTY));
         try (CloseableHttpClient client = HttpClients.custom().setSSLContext(sslContext).build()) {
             // Execute a GET on a site known to have a valid certificate signed by a trusted public CA
-            // This will result in a SSLHandshakeException if the SSLContext does not trust the CA, but the default
+            // This will result in an SSLHandshakeException if the SSLContext does not trust the CA, but the default
             // truststore trusts all common public CAs so the handshake will succeed
             privilegedConnect(() -> client.execute(new HttpGet("https://www.elastic.co/")).close());
         }
@@ -745,7 +745,7 @@ public void testThatSSLIOSessionStrategyWithoutSettingsWorks() throws Exception
             client.start();
 
             // Execute a GET on a site known to have a valid certificate signed by a trusted public CA
-            // This will result in a SSLHandshakeException if the SSLContext does not trust the CA, but the default
+            // This will result in an SSLHandshakeException if the SSLContext does not trust the CA, but the default
             // truststore trusts all common public CAs so the handshake will succeed
             client.execute(new HttpHost("elastic.co", 443, "https"), new HttpGet("/"), new AssertionCallback()).get();
         }

x-pack/plugin/security/cli/src/main/java/org/elasticsearch/xpack/security/cli/CertificateGenerateTool.java

@@ -529,7 +529,7 @@ private static void printIntro(Terminal terminal, boolean csr) {
             terminal.println("      the certificate and private key will also be included in the output file.");
         }
         terminal.println("* Information about each instance");
-        terminal.println("    * An instance is any piece of the Elastic Stack that requires a SSL certificate.");
+        terminal.println("    * An instance is any piece of the Elastic Stack that requires an SSL certificate.");
         terminal.println("      Depending on your configuration, Elasticsearch, Logstash, Kibana, and Beats");
         terminal.println("      may all require a certificate and private key.");
         terminal.println("    * The minimum required value for each instance is a name. This can simply be the");

x-pack/plugin/security/cli/src/main/java/org/elasticsearch/xpack/security/cli/CertificateTool.java

@@ -149,7 +149,7 @@ public static void main(String[] args) throws Exception {
         "signing requests for use with SSL/TLS in the Elastic stack.";
 
     static final String INSTANCE_EXPLANATION =
-        "    * An instance is any piece of the Elastic Stack that requires a SSL certificate.\n" +
+        "    * An instance is any piece of the Elastic Stack that requires an SSL certificate.\n" +
             "      Depending on your configuration, Elasticsearch, Logstash, Kibana, and Beats\n" +
             "      may all require a certificate and private key.\n" +
             "    * The minimum required value for each instance is a name. This can simply be the\n" +

x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ldap/LdapUserSearchSessionFactoryTests.java

@@ -59,7 +59,7 @@ public void init() throws Exception {
         Environment env = TestEnvironment.newEnvironment(Settings.builder().put("path.home", createTempDir()).build());
         /*
          * Prior to each test we reinitialize the socket factory with a new SSLService so that we get a new SSLContext.
-         * If we re-use a SSLContext, previously connected sessions can get re-established which breaks hostname
+         * If we re-use an SSLContext, previously connected sessions can get re-established which breaks hostname
          * verification tests since a re-established connection does not perform hostname verification.
          */
 

x-pack/qa/openldap-tests/src/test/java/org/elasticsearch/test/OpenLdapTests.java

@@ -84,7 +84,7 @@ public void initializeSslSocketFactory() throws Exception {
         Path truststore = getDataPath(LDAPTRUST_PATH);
         /*
          * Prior to each test we reinitialize the socket factory with a new SSLService so that we get a new SSLContext.
-         * If we re-use a SSLContext, previously connected sessions can get re-established which breaks hostname
+         * If we re-use an SSLContext, previously connected sessions can get re-established which breaks hostname
          * verification tests since a re-established connection does not perform hostname verification.
          */
         MockSecureSettings mockSecureSettings = new MockSecureSettings();

x-pack/qa/openldap-tests/src/test/java/org/elasticsearch/xpack/security/authc/ldap/OpenLdapUserSearchSessionFactoryTests.java

@@ -53,7 +53,7 @@ public void init() {
         Path caPath = getDataPath(LDAPCACERT_PATH);
         /*
          * Prior to each test we reinitialize the socket factory with a new SSLService so that we get a new SSLContext.
-         * If we re-use a SSLContext, previously connected sessions can get re-established which breaks hostname
+         * If we re-use an SSLContext, previously connected sessions can get re-established which breaks hostname
          * verification tests since a re-established connection does not perform hostname verification.
          */
         globalSettings = Settings.builder()

x-pack/qa/third-party/active-directory/src/test/java/org/elasticsearch/xpack/security/authc/ldap/ADLdapUserSearchSessionFactoryTests.java

@@ -43,7 +43,7 @@ public void init() throws Exception {
         Environment env = TestEnvironment.newEnvironment(Settings.builder().put("path.home", createTempDir()).build());
         /*
          * Prior to each test we reinitialize the socket factory with a new SSLService so that we get a new SSLContext.
-         * If we re-use a SSLContext, previously connected sessions can get re-established which breaks hostname
+         * If we re-use an SSLContext, previously connected sessions can get re-established which breaks hostname
          * verification tests since a re-established connection does not perform hostname verification.
          */
 

x-pack/qa/third-party/active-directory/src/test/java/org/elasticsearch/xpack/security/authc/ldap/AbstractActiveDirectoryTestCase.java

@@ -78,7 +78,7 @@ public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IO
         });
         /*
          * Prior to each test we reinitialize the socket factory with a new SSLService so that we get a new SSLContext.
-         * If we re-use a SSLContext, previously connected sessions can get re-established which breaks hostname
+         * If we re-use an SSLContext, previously connected sessions can get re-established which breaks hostname
          * verification tests since a re-established connection does not perform hostname verification.
          */
         Settings.Builder builder = Settings.builder().put("path.home", createTempDir());