Clean up- adding Standard Charset constant

Author: sarveshkaushal

util/src/main/java/io/kubernetes/client/util/authenticators/OpenIDConnectAuthenticator.java

@@ -129,7 +129,8 @@ public Map<String, Object> refresh(Map<String, Object> config) {
       try {
         ks = java.security.KeyStore.getInstance("PKCS12");
         ks.load(null, alias.toCharArray());
-        ByteArrayInputStream bais = new ByteArrayInputStream(pemCert.getBytes("UTF-8"));
+        ByteArrayInputStream bais =
+            new ByteArrayInputStream(pemCert.getBytes(StandardCharsets.UTF_8));
         CertificateFactory cf = CertificateFactory.getInstance("X.509");
         Collection<? extends java.security.cert.Certificate> c = cf.generateCertificates(bais);
 
@@ -206,7 +207,7 @@ private JSONObject refreshOidcToken(
                       .append(':')
                       .append(clientSecret)
                       .toString()
-                      .getBytes("UTF-8"));
+                      .getBytes(StandardCharsets.UTF_8));
       https.setRequestProperty(
           "Authorization", new StringBuilder().append("Basic ").append(credentials).toString());
       https.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
@@ -219,7 +220,7 @@ private JSONObject refreshOidcToken(
               .append("&grant_type=refresh_token")
               .toString();
       OutputStream ou = https.getOutputStream();
-      ou.write(urlData.getBytes("UTF-8"));
+      ou.write(urlData.getBytes(StandardCharsets.UTF_8));
       ou.flush();
       ou.close();
 

util/src/main/java/io/kubernetes/client/util/credentials/UsernamePasswordAuthentication.java

@@ -13,7 +13,7 @@
 package io.kubernetes.client.util.credentials;
 
 import io.kubernetes.client.openapi.ApiClient;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import okio.ByteString;
 
 /**
@@ -33,6 +33,6 @@ public void provide(ApiClient client) {
     final String usernameAndPassword = username + ":" + password;
     client.setApiKeyPrefix("Basic");
     client.setApiKey(
-        ByteString.of(usernameAndPassword.getBytes(Charset.forName("ISO-8859-1"))).base64());
+        ByteString.of(usernameAndPassword.getBytes(StandardCharsets.ISO_8859_1)).base64());
   }
 }

util/src/test/java/io/kubernetes/client/util/KubeConfigTest.java

@@ -22,6 +22,7 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.util.Map;
 import org.junit.Rule;
@@ -61,7 +62,7 @@ public void testToken() {
   public void testTokenFile() throws IOException {
     String token = "flubble";
     File tokenFile = folder.newFile("token-file.txt");
-    Files.write(tokenFile.toPath(), token.getBytes("UTF-8"));
+    Files.write(tokenFile.toPath(), token.getBytes(StandardCharsets.UTF_8));
 
     String replace = KUBECONFIG_TOKEN.replace("foobaz", tokenFile.getCanonicalPath());
     replace = replace.replace("token:", "tokenFile:");

util/src/test/java/io/kubernetes/client/util/credentials/OpenIDConnectAuthenticationTest.java

@@ -21,6 +21,7 @@
 import io.kubernetes.client.util.TestUtils;
 import io.kubernetes.client.util.authenticators.OpenIDConnectAuthenticator;
 import java.io.FileInputStream;
+import java.nio.charset.StandardCharsets;
 import java.security.KeyStore;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
@@ -183,7 +184,8 @@ public void testRefreshSuccess() throws Exception {
     config.put(
         OpenIDConnectAuthenticator.OIDC_IDP_CERT_DATA,
         Base64.encodeBase64String(
-            exportCert((X509Certificate) serverKs.getCertificate("mykey")).getBytes("UTF-8")));
+            exportCert((X509Certificate) serverKs.getCertificate("mykey"))
+                .getBytes(StandardCharsets.UTF_8)));
 
     Map<String, Object> respMap = oidcAuth.refresh(config);
 
@@ -237,7 +239,8 @@ public void testRefreshUnauthorized() throws Exception {
     config.put(
         OpenIDConnectAuthenticator.OIDC_IDP_CERT_DATA,
         Base64.encodeBase64String(
-            exportCert((X509Certificate) serverKs.getCertificate("mykey")).getBytes("UTF-8")));
+            exportCert((X509Certificate) serverKs.getCertificate("mykey"))
+                .getBytes(StandardCharsets.UTF_8)));
 
     Map<String, Object> respMap = oidcAuth.refresh(config);
   }