Use Charset variants of URLEncoder and URLDecoder methods

spring-beans/src/main/java/org/springframework/beans/factory/xml/ResourceEntityResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.io.File;
 import java.io.IOException;
 import java.net.URL;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -80,7 +81,7 @@ public class ResourceEntityResolver extends DelegatingEntityResolver {
 		if (source == null && systemId != null) {
 			String resourcePath = null;
 			try {
-				String decodedSystemId = URLDecoder.decode(systemId, "UTF-8");
+				String decodedSystemId = URLDecoder.decode(systemId, StandardCharsets.UTF_8);
 				String givenUrl = new URL(decodedSystemId).toString();
 				String systemRootUrl = new File("").toURI().toURL().toString();
 				// Try relative to resource base if currently in system root.

spring-oxm/src/main/java/org/springframework/oxm/jaxb/Jaxb2Marshaller.java

@@ -22,7 +22,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.StringReader;
-import java.io.UnsupportedEncodingException;
 import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
@@ -1025,12 +1024,7 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
 		public DataHandler getAttachmentAsDataHandler(String contentId) {
 			if (contentId.startsWith(CID)) {
 				contentId = contentId.substring(CID.length());
-				try {
-					contentId = URLDecoder.decode(contentId, "UTF-8");
-				}
-				catch (UnsupportedEncodingException ex) {
-					// ignore
-				}
+				contentId = URLDecoder.decode(contentId, StandardCharsets.UTF_8);
 				contentId = '<' + contentId + '>';
 			}
 			DataHandler dataHandler = this.mimeContainer.getAttachment(contentId);

spring-test/src/main/java/org/springframework/test/web/servlet/htmlunit/HtmlUnitRequestBuilder.java

@@ -18,7 +18,6 @@ package org.springframework.test.web.servlet.htmlunit;
 
 import java.io.File;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.nio.charset.Charset;
@@ -396,12 +395,7 @@ final class HtmlUnitRequestBuilder implements RequestBuilder, Mergeable {
 	}
 
 	private String urlDecode(String value) {
-		try {
-			return URLDecoder.decode(value, "UTF-8");
-		}
-		catch (UnsupportedEncodingException ex) {
-			throw new IllegalStateException(ex);
-		}
+		return URLDecoder.decode(value, StandardCharsets.UTF_8);
 	}
 
 	private byte[] readAllBytes(File file) {

spring-web/src/main/java/org/springframework/http/codec/FormHttpMessageReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-web/src/main/java/org/springframework/http/codec/FormHttpMessageWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-web/src/main/java/org/springframework/http/server/reactive/AbstractServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,9 @@
 
 package org.springframework.http.server.reactive;
 
-import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -158,15 +158,8 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 		return queryParams;
 	}
 
-	@SuppressWarnings("deprecation")
 	private String decodeQueryParam(String value) {
-		try {
-			return URLDecoder.decode(value, "UTF-8");
-		}
-		catch (UnsupportedEncodingException ex) {
-			// Should never happen but we got a platform default fallback anyway.
-			return URLDecoder.decode(value);
-		}
+		return URLDecoder.decode(value, StandardCharsets.UTF_8);
 	}
 
 	@Override

spring-webflux/src/main/java/org/springframework/web/reactive/resource/PathResourceResolver.java

@@ -17,7 +17,6 @@
 package org.springframework.web.reactive.resource;
 
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
@@ -199,14 +198,14 @@ public class PathResourceResolver extends AbstractResourceResolver {
 		if (resourcePath.contains("%")) {
 			// Use URLDecoder (vs UriUtils) to preserve potentially decoded UTF-8 chars...
 			try {
-				String decodedPath = URLDecoder.decode(resourcePath, "UTF-8");
+				String decodedPath = URLDecoder.decode(resourcePath, StandardCharsets.UTF_8);
 				if (decodedPath.contains("../") || decodedPath.contains("..\\")) {
 					logger.warn("Resolved resource path contains encoded \"../\" or \"..\\\": " + resourcePath);
 					return true;
 				}
 			}
-			catch (IllegalArgumentException | UnsupportedEncodingException ex) {
-				// Should never happen...
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
 			}
 		}
 		return false;

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -17,8 +17,8 @@
 package org.springframework.web.reactive.resource;
 
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -534,7 +534,7 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 		if (path.contains("%")) {
 			try {
 				// Use URLDecoder (vs UriUtils) to preserve potentially decoded UTF-8 chars
-				String decodedPath = URLDecoder.decode(path, "UTF-8");
+				String decodedPath = URLDecoder.decode(path, StandardCharsets.UTF_8);
 				if (isInvalidPath(decodedPath)) {
 					return true;
 				}
@@ -543,8 +543,8 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 					return true;
 				}
 			}
-			catch (IllegalArgumentException | UnsupportedEncodingException ex) {
-				// Should never happen...
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
 			}
 		}
 		return false;

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/PathResourceResolver.java

@@ -17,7 +17,6 @@
 package org.springframework.web.servlet.resource;
 
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
@@ -295,14 +294,14 @@ public class PathResourceResolver extends AbstractResourceResolver {
 		if (resourcePath.contains("%")) {
 			// Use URLDecoder (vs UriUtils) to preserve potentially decoded UTF-8 chars...
 			try {
-				String decodedPath = URLDecoder.decode(resourcePath, "UTF-8");
+				String decodedPath = URLDecoder.decode(resourcePath, StandardCharsets.UTF_8);
 				if (decodedPath.contains("../") || decodedPath.contains("..\\")) {
 					logger.warn("Resolved resource path contains encoded \"../\" or \"..\\\": " + resourcePath);
 					return true;
 				}
 			}
-			catch (IllegalArgumentException | UnsupportedEncodingException ex) {
-				// May not be possible to decode... | Should never happen...
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
 			}
 		}
 		return false;

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -17,9 +17,9 @@
 package org.springframework.web.servlet.resource;
 
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -694,7 +694,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 		if (path.contains("%")) {
 			try {
 				// Use URLDecoder (vs UriUtils) to preserve potentially decoded UTF-8 chars
-				String decodedPath = URLDecoder.decode(path, "UTF-8");
+				String decodedPath = URLDecoder.decode(path, StandardCharsets.UTF_8);
 				if (isInvalidPath(decodedPath)) {
 					return true;
 				}
@@ -703,8 +703,8 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 					return true;
 				}
 			}
-			catch (IllegalArgumentException | UnsupportedEncodingException ex) {
-				// May not be possible to decode... | Should never happen...
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
 			}
 		}
 		return false;

spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.web.servlet.support;
 
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -291,7 +292,7 @@ public class FlashMapManagerTests {
 
 	@Test // SPR-12569
 	public void flashAttributesWithQueryParamsWithSpace() throws Exception {
-		String encodedValue = URLEncoder.encode("1 2", "UTF-8");
+		String encodedValue = URLEncoder.encode("1 2", StandardCharsets.UTF_8);
 
 		FlashMap flashMap = new FlashMap();
 		flashMap.put("key", "value");