Using StandartCharsets and removing UnsupportedEncodingException (helidon-io#3479)

* Using StandartCharsets and removing UnsupportedEncodingException

* fix checkstyle and copyright warnings

Author: Captain1653

media/common/src/main/java/io/helidon/media/common/ContentReaders.java

@@ -19,7 +19,6 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
@@ -168,15 +167,7 @@ private static final class StringToDecodedString implements Mapper<String, Strin
 
         @Override
         public String map(String s) {
-            try {
-                return URLDecoder.decode(s, charset.name());
-            } catch (UnsupportedEncodingException e) {
-                /*
-                 * Convert the encoding exception into an unchecked one to simplify the mapper's use
-                 * in lambdas.
-                 */
-                throw new RuntimeException(e);
-            }
+            return URLDecoder.decode(s, charset);
         }
     }
     /**

media/multipart/src/main/java/io/helidon/media/multipart/MimeParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Oracle and/or its affiliates.
+ * Copyright (c) 2020, 2021 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,9 @@
  */
 package io.helidon.media.multipart;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -245,7 +245,7 @@ private ParsingException(Throwable cause) {
     }
 
     private static final Logger LOGGER = Logger.getLogger(MimeParser.class.getName());
-    private static final Charset HEADER_ENCODING = Charset.forName("ISO8859-1");
+    private static final Charset HEADER_ENCODING = StandardCharsets.ISO_8859_1;
 
     /**
      * All states.
@@ -696,8 +696,6 @@ private void skipPreamble() {
      * @return a header line or an empty string if the blank line separating the
      * header from the body has been reached, or {@code null} if the there is
      * no more data in the buffer
-     * @throws UnsupportedEncodingException if an error occurs while decoding
-     * from the buffer
      */
     private String readHeaderLine() {
         // FIXME: what about multi-line headers?

microprofile/openapi/src/main/java/io/helidon/microprofile/openapi/OpenApiCdiExtension.java

@@ -20,7 +20,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintStream;
-import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
@@ -213,16 +212,16 @@ private List<URL> findIndexFiles(String... indexPaths) throws IOException {
         return result;
     }
 
-    private static void dumpIndex(Level level, Index index) throws UnsupportedEncodingException {
+    private static void dumpIndex(Level level, Index index) {
         if (LOGGER.isLoggable(level)) {
             LOGGER.log(level, "Dump of internal Jandex index:");
             PrintStream oldStdout = System.out;
             ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            try (PrintStream newPS = new PrintStream(baos, true, Charset.defaultCharset().name())) {
+            try (PrintStream newPS = new PrintStream(baos, true, Charset.defaultCharset())) {
                 System.setOut(newPS);
                 index.printAnnotations();
                 index.printSubclasses();
-                LOGGER.log(level, baos.toString(Charset.defaultCharset().name()));
+                LOGGER.log(level, baos.toString(Charset.defaultCharset()));
             } finally {
                 System.setOut(oldStdout);
             }

webserver/test-support/src/main/java/io/helidon/webserver/testsupport/TestRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2020 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2021 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package io.helidon.webserver.testsupport;
 
-import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
@@ -96,7 +95,7 @@ public TestRequest queryParameter(String name, String value) {
     public TestRequest header(String name, String value) {
         Objects.requireNonNull(name, "Parameter 'name' is null!");
         Objects.requireNonNull(name, "Parameter 'value' is null!");
-        headers.computeIfAbsent(name, k -> new ArrayList()).add(value);
+        headers.computeIfAbsent(name, k -> new ArrayList<>()).add(value);
         return this;
     }
 
@@ -310,11 +309,6 @@ public TestResponse call(Http.RequestMethod method) throws InterruptedException,
     }
 
     private String encode(String str) {
-        try {
-            return URLEncoder.encode(str, StandardCharsets.UTF_8.toString());
-        } catch (UnsupportedEncodingException e) {
-            // Rare case. Should never happen in java
-            throw new IllegalStateException("UTF-8 is not supported!", e);
-        }
+        return URLEncoder.encode(str, StandardCharsets.UTF_8);
     }
 }

webserver/webserver/src/main/java/io/helidon/webserver/UriComponent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2020 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2021 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,13 @@
 
 package io.helidon.webserver;
 
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 
 import io.helidon.common.http.HashParameters;
 import io.helidon.common.http.Parameters;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 /**
  * Extracted from Jersey
  * <p>
@@ -86,22 +87,17 @@ static Parameters decodeQuery(String query, boolean decodeNames, boolean decodeV
     }
 
     private static void decodeQueryParam(Parameters params, String param, boolean decodeNames, boolean decodeValues) {
-        try {
-            int equals = param.indexOf('=');
-            if (equals > 0) {
-                params.add((decodeNames) ? URLDecoder.decode(param.substring(0, equals), "UTF-8") : param.substring(0, equals),
-                           (decodeValues)
-                                   ? URLDecoder.decode(param.substring(equals + 1), "UTF-8")
-                                   : param.substring(equals + 1));
-            } else if (equals == 0) {
-                // no key declared, ignore
-                return;
-            } else if (!param.isEmpty()) {
-                params.add((decodeNames) ? URLDecoder.decode(param, "UTF-8") : param, "");
-            }
-        } catch (UnsupportedEncodingException ex) {
-            // This should never occur
-            throw new IllegalArgumentException("Should never occur!", ex);
+        int equals = param.indexOf('=');
+        if (equals > 0) {
+            params.add((decodeNames) ? URLDecoder.decode(param.substring(0, equals), UTF_8) : param.substring(0, equals),
+                       (decodeValues)
+                               ? URLDecoder.decode(param.substring(equals + 1), UTF_8)
+                               : param.substring(equals + 1));
+        } else if (equals == 0) {
+            // no key declared, ignore
+            return;
+        } else if (!param.isEmpty()) {
+            params.add((decodeNames) ? URLDecoder.decode(param, UTF_8) : param, "");
         }
     }
 }