Revised Charset handling and common StringUtils.uriDecode delegate

Issue: SPR-14492

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -16,6 +16,8 @@
 
 package org.springframework.util;
 
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -690,6 +692,59 @@ public abstract class StringUtils {
 		return cleanPath(path1).equals(cleanPath(path2));
 	}
 
+	/**
+	 * Decode the given encoded URI component value. Based on the following rules:
+	 * <ul>
+	 * <li>Alphanumeric characters {@code "a"} through {@code "z"}, {@code "A"} through {@code "Z"},
+	 * and {@code "0"} through {@code "9"} stay the same.</li>
+	 * <li>Special characters {@code "-"}, {@code "_"}, {@code "."}, and {@code "*"} stay the same.</li>
+	 * <li>A sequence "{@code %<i>xy</i>}" is interpreted as a hexadecimal representation of the character.</li>
+	 * </ul>
+	 * @param source the encoded String (may be {@code null})
+	 * @param charset the character set
+	 * @return the decoded value
+	 * @throws IllegalArgumentException when the given source contains invalid encoded sequences
+	 * @since 5.0
+	 * @see java.net.URLDecoder#decode(String, String)
+	 */
+	public static String uriDecode(String source, Charset charset) {
+		if (source == null) {
+			return null;
+		}
+		int length = source.length();
+		if (length == 0) {
+			return source;
+		}
+		Assert.notNull(charset, "Charset must not be null");
+
+		ByteArrayOutputStream bos = new ByteArrayOutputStream(length);
+		boolean changed = false;
+		for (int i = 0; i < length; i++) {
+			int ch = source.charAt(i);
+			if (ch == '%') {
+				if (i + 2 < length) {
+					char hex1 = source.charAt(i + 1);
+					char hex2 = source.charAt(i + 2);
+					int u = Character.digit(hex1, 16);
+					int l = Character.digit(hex2, 16);
+					if (u == -1 || l == -1) {
+						throw new IllegalArgumentException("Invalid encoded sequence \"" + source.substring(i) + "\"");
+					}
+					bos.write((char) ((u << 4) + l));
+					i += 2;
+					changed = true;
+				}
+				else {
+					throw new IllegalArgumentException("Invalid encoded sequence \"" + source.substring(i) + "\"");
+				}
+			}
+			else {
+				bos.write(ch);
+			}
+		}
+		return (changed ? new String(bos.toByteArray(), charset) : source);
+	}
+
 	/**
 	 * Parse the given {@code localeString} value into a {@link Locale}.
 	 * <p>This is the inverse operation of {@link Locale#toString Locale's toString}.

spring-web-reactive/src/main/java/org/springframework/web/reactive/function/server/PathResourceLookupFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -30,7 +30,6 @@ import org.springframework.util.AntPathMatcher;
 import org.springframework.util.PathMatcher;
 import org.springframework.util.ResourceUtils;
 import org.springframework.util.StringUtils;
-import org.springframework.web.util.UriUtils;
 
 /**
  * Lookup function used by {@link RouterFunctions#resources(String, Resource)}.
@@ -55,7 +54,7 @@ class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resourc
 	public Mono<Resource> apply(ServerRequest request) {
 		String path = processPath(request.path());
 		if (path.contains("%")) {
-			path = UriUtils.decode(path, StandardCharsets.UTF_8);
+			path = StringUtils.uriDecode(path, StandardCharsets.UTF_8);
 		}
 		if (!StringUtils.hasLength(path) || isInvalidPath(path)) {
 			return Mono.empty();
@@ -116,8 +115,7 @@ class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resourc
 		return false;
 	}
 
-	private boolean isResourceUnderLocation(Resource resource) throws
-			IOException {
+	private boolean isResourceUnderLocation(Resource resource) throws IOException {
 		if (resource.getClass() != this.location.getClass()) {
 			return false;
 		}
@@ -148,7 +146,7 @@ class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resourc
 		}
 
 		if (resourcePath.contains("%")) {
-			if (UriUtils.decode(resourcePath, "UTF-8").contains("../")) {
+			if (StringUtils.uriDecode(resourcePath, StandardCharsets.UTF_8).contains("../")) {
 				return false;
 			}
 		}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -27,7 +27,6 @@ import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
-import org.springframework.web.util.UriUtils;
 
 /**
  * Common base class for {@link ServerHttpRequest} implementations.
@@ -81,7 +80,6 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 	/**
 	 * A method for parsing of the query into name-value pairs. The return
 	 * value is turned into an immutable map and cached.
-	 *
 	 * <p>Note that this method is invoked lazily on first access to
 	 * {@link #getQueryParams()}. The invocation is not synchronized but the
 	 * parsing is thread-safe nevertheless.
@@ -102,8 +100,8 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 		return queryParams;
 	}
 
-	private static String decodeQueryParam(String value) {
-		return (value != null ? UriUtils.decode(value, StandardCharsets.UTF_8) : null);
+	private String decodeQueryParam(String value) {
+		return StringUtils.uriDecode(value, StandardCharsets.UTF_8);
 	}
 
 	@Override

spring-web/src/main/java/org/springframework/web/util/HierarchicalUriComponents.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -18,11 +18,9 @@ package org.springframework.web.util;
 
 import java.io.ByteArrayOutputStream;
 import java.io.Serializable;
-import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -51,6 +49,9 @@ final class HierarchicalUriComponents extends UriComponents {
 
 	private static final char PATH_DELIMITER = '/';
 
+	private static final String PATH_DELIMITER_STRING = "/";
+
+
 	private final String userInfo;
 
 	private final String host;
@@ -183,10 +184,9 @@ final class HierarchicalUriComponents extends UriComponents {
 	 * the result as a new {@code UriComponents} instance.
 	 * @param charset the encoding of the values contained in this map
 	 * @return the encoded uri components
-	 * @throws UnsupportedEncodingException if the given encoding is not supported
 	 */
 	@Override
-	public HierarchicalUriComponents encode(Charset charset) throws UnsupportedEncodingException {
+	public HierarchicalUriComponents encode(Charset charset) {
 		if (this.encoded) {
 			return this;
 		}
@@ -200,7 +200,7 @@ final class HierarchicalUriComponents extends UriComponents {
 				pathTo, paramsTo, fragmentTo, true, false);
 	}
 
-	private MultiValueMap<String, String> encodeQueryParams(Charset charset) throws UnsupportedEncodingException {
+	private MultiValueMap<String, String> encodeQueryParams(Charset charset) {
 		int size = this.queryParams.size();
 		MultiValueMap<String, String> result = new LinkedMultiValueMap<>(size);
 		for (Map.Entry<String, List<String>> entry : this.queryParams.entrySet()) {
@@ -234,21 +234,19 @@ final class HierarchicalUriComponents extends UriComponents {
 	 * @param charset the encoding of the source string
 	 * @param type the URI component for the source
 	 * @return the encoded URI
-	 * @throws IllegalArgumentException when the given uri parameter is not a valid URI
+	 * @throws IllegalArgumentException when the given value is not a valid URI component
 	 */
 	static String encodeUriComponent(String source, Charset charset, Type type) {
-		if (source == null) {
-			return null;
+		if (!StringUtils.hasLength(source)) {
+			return source;
 		}
-		byte[] bytes = encodeBytes(source.getBytes(charset), type);
-		return new String(bytes, StandardCharsets.US_ASCII);
-	}
-
-	private static byte[] encodeBytes(byte[] source, Type type) {
-		Assert.notNull(source, "Source must not be null");
+		Assert.notNull(charset, "Charset must not be null");
 		Assert.notNull(type, "Type must not be null");
-		ByteArrayOutputStream bos = new ByteArrayOutputStream(source.length);
-		for (byte b : source) {
+
+		byte[] bytes = source.getBytes(charset);
+		ByteArrayOutputStream bos = new ByteArrayOutputStream(bytes.length);
+		boolean changed = false;
+		for (byte b : bytes) {
 			if (b < 0) {
 				b += 256;
 			}
@@ -261,13 +259,14 @@ final class HierarchicalUriComponents extends UriComponents {
 				char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, 16));
 				bos.write(hex1);
 				bos.write(hex2);
+				changed = true;
 			}
 		}
-		return bos.toByteArray();
+		return (changed ? new String(bos.toByteArray(), charset) : source);
 	}
 
 	private Type getHostType() {
-		return (this.host != null && this.host.startsWith("[")) ? Type.HOST_IPV6 : Type.HOST_IPV4;
+		return (this.host != null && this.host.startsWith("[") ? Type.HOST_IPV6 : Type.HOST_IPV4);
 	}
 
 
@@ -586,7 +585,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isAlpha(int c) {
-			return c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z';
+			return (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z');
 		}
 
 		/**
@@ -594,7 +593,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isDigit(int c) {
-			return c >= '0' && c <= '9';
+			return (c >= '0' && c <= '9');
 		}
 
 		/**
@@ -602,7 +601,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isGenericDelimiter(int c) {
-			return ':' == c || '/' == c || '?' == c || '#' == c || '[' == c || ']' == c || '@' == c;
+			return (':' == c || '/' == c || '?' == c || '#' == c || '[' == c || ']' == c || '@' == c);
 		}
 
 		/**
@@ -610,8 +609,8 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isSubDelimiter(int c) {
-			return '!' == c || '$' == c || '&' == c || '\'' == c || '(' == c || ')' == c || '*' == c || '+' == c ||
-					',' == c || ';' == c || '=' == c;
+			return ('!' == c || '$' == c || '&' == c || '\'' == c || '(' == c || ')' == c || '*' == c || '+' == c ||
+					',' == c || ';' == c || '=' == c);
 		}
 
 		/**
@@ -619,7 +618,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isReserved(int c) {
-			return isGenericDelimiter(c) || isSubDelimiter(c);
+			return (isGenericDelimiter(c) || isSubDelimiter(c));
 		}
 
 		/**
@@ -627,7 +626,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isUnreserved(int c) {
-			return isAlpha(c) || isDigit(c) || '-' == c || '.' == c || '_' == c || '~' == c;
+			return (isAlpha(c) || isDigit(c) || '-' == c || '.' == c || '_' == c || '~' == c);
 		}
 
 		/**
@@ -635,7 +634,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		 * @see <a href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986, appendix A</a>
 		 */
 		protected boolean isPchar(int c) {
-			return isUnreserved(c) || isSubDelimiter(c) || ':' == c || '@' == c;
+			return (isUnreserved(c) || isSubDelimiter(c) || ':' == c || '@' == c);
 		}
 	}
 
@@ -649,7 +648,7 @@ final class HierarchicalUriComponents extends UriComponents {
 
 		List<String> getPathSegments();
 
-		PathComponent encode(Charset charset) throws UnsupportedEncodingException;
+		PathComponent encode(Charset charset);
 
 		void verify();
 
@@ -666,7 +665,6 @@ final class HierarchicalUriComponents extends UriComponents {
 
 		private final String path;
 
-
 		public FullPathComponent(String path) {
 			this.path = path;
 		}
@@ -678,13 +676,12 @@ final class HierarchicalUriComponents extends UriComponents {
 
 		@Override
 		public List<String> getPathSegments() {
-			String delimiter = new String(new char[] {PATH_DELIMITER});
-			String[] pathSegments = StringUtils.tokenizeToStringArray(path, delimiter);
-			return Collections.unmodifiableList(Arrays.asList(pathSegments));
+			String[] segments = StringUtils.tokenizeToStringArray(this.path, PATH_DELIMITER_STRING);
+			return Collections.unmodifiableList(Arrays.asList(segments));
 		}
 
 		@Override
-		public PathComponent encode(Charset charset) throws UnsupportedEncodingException {
+		public PathComponent encode(Charset charset) {
 			String encodedPath = encodeUriComponent(getPath(), charset, Type.PATH);
 			return new FullPathComponent(encodedPath);
 		}
@@ -750,7 +747,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		}
 
 		@Override
-		public PathComponent encode(Charset charset) throws UnsupportedEncodingException {
+		public PathComponent encode(Charset charset) {
 			List<String> pathSegments = getPathSegments();
 			List<String> encodedPathSegments = new ArrayList<>(pathSegments.size());
 			for (String pathSegment : pathSegments) {
@@ -827,7 +824,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		}
 
 		@Override
-		public PathComponent encode(Charset charset) throws UnsupportedEncodingException {
+		public PathComponent encode(Charset charset) {
 			List<PathComponent> encodedComponents = new ArrayList<>(this.pathComponents.size());
 			for (PathComponent pathComponent : this.pathComponents) {
 				encodedComponents.add(pathComponent.encode(charset));
@@ -873,7 +870,7 @@ final class HierarchicalUriComponents extends UriComponents {
 			return Collections.emptyList();
 		}
 		@Override
-		public PathComponent encode(Charset charset) throws UnsupportedEncodingException {
+		public PathComponent encode(Charset charset) {
 			return this;
 		}
 		@Override

spring-web/src/main/java/org/springframework/web/util/OpaqueUriComponents.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.web.util;
 
-import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.Charset;
@@ -90,7 +89,7 @@ final class OpaqueUriComponents extends UriComponents {
 	}
 
 	@Override
-	public UriComponents encode(Charset charset) throws UnsupportedEncodingException {
+	public UriComponents encode(Charset charset) {
 		return this;
 	}
 

spring-web/src/main/java/org/springframework/web/util/UriComponents.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -17,7 +17,6 @@
 package org.springframework.web.util;
 
 import java.io.Serializable;
-import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
@@ -44,7 +43,9 @@ import org.springframework.util.MultiValueMap;
 @SuppressWarnings("serial")
 public abstract class UriComponents implements Serializable {
 
-	/** Captures URI template variable names. */
+	/**
+	 * Captures URI template variable names.
+	 */
 	private static final Pattern NAMES_PATTERN = Pattern.compile("\\{([^/]+?)\\}");
 
 
@@ -59,57 +60,57 @@ public abstract class UriComponents implements Serializable {
 	}
 
 
-	// component getters
+	// Component getters
 
 	/**
-	 * Returns the scheme. Can be {@code null}.
+	 * Return the scheme. Can be {@code null}.
 	 */
 	public final String getScheme() {
 		return this.scheme;
 	}
 
 	/**
-	 * Returns the scheme specific part. Can be {@code null}.
+	 * Return the scheme specific part. Can be {@code null}.
 	 */
 	public abstract String getSchemeSpecificPart();
 
 	/**
-	 * Returns the user info. Can be {@code null}.
+	 * Return the user info. Can be {@code null}.
 	 */
 	public abstract String getUserInfo();
 
 	/**
-	 * Returns the host. Can be {@code null}.
+	 * Return the host. Can be {@code null}.
 	 */
 	public abstract String getHost();
 
 	/**
-	 * Returns the port. Returns {@code -1} if no port has been set.
+	 * Return the port. {@code -1} if no port has been set.
 	 */
 	public abstract int getPort();
 
 	/**
-	 * Returns the path. Can be {@code null}.
+	 * Return the path. Can be {@code null}.
 	 */
 	public abstract String getPath();
 
 	/**
-	 * Returns the list of path segments. Empty if no path has been set.
+	 * Return the list of path segments. Empty if no path has been set.
 	 */
 	public abstract List<String> getPathSegments();
 
 	/**
-	 * Returns the query. Can be {@code null}.
+	 * Return the query. Can be {@code null}.
 	 */
 	public abstract String getQuery();
 
 	/**
-	 * Returns the map of query parameters. Empty if no query has been set.
+	 * Return the map of query parameters. Empty if no query has been set.
 	 */
 	public abstract MultiValueMap<String, String> getQueryParams();
 
 	/**
-	 * Returns the fragment. Can be {@code null}.
+	 * Return the fragment. Can be {@code null}.
 	 */
 	public final String getFragment() {
 		return this.fragment;
@@ -122,13 +123,7 @@ public abstract class UriComponents implements Serializable {
 	 * @return the encoded URI components
 	 */
 	public final UriComponents encode() {
-		try {
-			return encode(StandardCharsets.UTF_8);
-		}
-		catch (UnsupportedEncodingException ex) {
-			// should not occur
-			throw new IllegalStateException(ex);
-		}
+		return encode(StandardCharsets.UTF_8);
 	}
 
 	/**
@@ -136,9 +131,8 @@ public abstract class UriComponents implements Serializable {
 	 * returns the result as a new {@code UriComponents} instance.
 	 * @param charset the encoding of the values contained in this map
 	 * @return the encoded URI components
-	 * @throws UnsupportedEncodingException if the given encoding is not supported
 	 */
-	public abstract UriComponents encode(Charset charset) throws UnsupportedEncodingException;
+	public abstract UriComponents encode(Charset charset) ;
 
 	/**
 	 * Replace all URI template variables with the values from a given map.

spring-web/src/main/java/org/springframework/web/util/UriUtils.java

@@ -16,11 +16,10 @@
 
 package org.springframework.web.util;
 
-import java.io.ByteArrayOutputStream;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
 
-import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * Utility class for URI encoding and decoding based on RFC 3986.
@@ -42,7 +41,7 @@ import org.springframework.util.Assert;
 public abstract class UriUtils {
 
 	/**
-	 * Encodes the given URI scheme with the given encoding.
+	 * Encode the given URI scheme with the given encoding.
 	 * @param scheme the scheme to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded scheme
@@ -53,7 +52,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI authority with the given encoding.
+	 * Encode the given URI authority with the given encoding.
 	 * @param authority the authority to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded authority
@@ -64,7 +63,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI user info with the given encoding.
+	 * Encode the given URI user info with the given encoding.
 	 * @param userInfo the user info to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded user info
@@ -75,7 +74,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI host with the given encoding.
+	 * Encode the given URI host with the given encoding.
 	 * @param host the host to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded host
@@ -86,7 +85,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI port with the given encoding.
+	 * Encode the given URI port with the given encoding.
 	 * @param port the port to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded port
@@ -97,7 +96,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI path with the given encoding.
+	 * Encode the given URI path with the given encoding.
 	 * @param path the path to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded path
@@ -108,7 +107,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI path segment with the given encoding.
+	 * Encode the given URI path segment with the given encoding.
 	 * @param segment the segment to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded segment
@@ -119,7 +118,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI query with the given encoding.
+	 * Encode the given URI query with the given encoding.
 	 * @param query the query to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded query
@@ -130,7 +129,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI query parameter with the given encoding.
+	 * Encode the given URI query parameter with the given encoding.
 	 * @param queryParam the query parameter to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded query parameter
@@ -141,7 +140,7 @@ public abstract class UriUtils {
 	}
 
 	/**
-	 * Encodes the given URI fragment with the given encoding.
+	 * Encode the given URI fragment with the given encoding.
 	 * @param fragment the fragment to be encoded
 	 * @param encoding the character encoding to encode to
 	 * @return the encoded fragment
@@ -165,72 +164,19 @@ public abstract class UriUtils {
 		HierarchicalUriComponents.Type type = HierarchicalUriComponents.Type.URI;
 		return HierarchicalUriComponents.encodeUriComponent(source, encoding, type);
 	}
-
-	// decoding
-
 	/**
-	 * Decodes the given encoded source String into an URI. Based on the following rules:
-	 * <ul>
-	 * <li>Alphanumeric characters {@code "a"} through {@code "z"}, {@code "A"} through {@code "Z"}, and
-	 * {@code "0"} through {@code "9"} stay the same.</li>
-	 * <li>Special characters {@code "-"}, {@code "_"}, {@code "."}, and {@code "*"} stay the same.</li>
-	 * <li>A sequence "{@code %<i>xy</i>}" is interpreted as a hexadecimal representation of the character.</li>
-	 * </ul>
-	 * @param source the source string
+	 * Decode the given encoded URI component.
+	 * <p>See {@link StringUtils#uriDecode(String, Charset) for the decoding rules.
+	 * @param source the encoded String
 	 * @param encoding the encoding
-	 * @return the decoded URI
+	 * @return the decoded value
 	 * @throws IllegalArgumentException when the given source contains invalid encoded sequences
 	 * @throws UnsupportedEncodingException when the given encoding parameter is not supported
+	 * @see StringUtils#uriDecode(String, Charset)
 	 * @see java.net.URLDecoder#decode(String, String)
 	 */
 	public static String decode(String source, String encoding) throws UnsupportedEncodingException {
-		return decode(source, Charset.forName(encoding));
-	}
-
-	/**
-	 * Decodes the given encoded source String into an URI. Based on the following rules:
-	 * <ul>
-	 * <li>Alphanumeric characters {@code "a"} through {@code "z"}, {@code "A"} through {@code "Z"}, and
-	 * {@code "0"} through {@code "9"} stay the same.</li>
-	 * <li>Special characters {@code "-"}, {@code "_"}, {@code "."}, and {@code "*"} stay the same.</li>
-	 * <li>A sequence "{@code %<i>xy</i>}" is interpreted as a hexadecimal representation of the character.</li>
-	 * </ul>
-	 * @param source the source string
-	 * @param charset the character set
-	 * @return the decoded URI
-	 * @throws IllegalArgumentException when the given source contains invalid encoded sequences
-	 * @see java.net.URLDecoder#decode(String, String)
-	 */
-	public static String decode(String source, Charset charset) {
-		Assert.notNull(source, "'source' must not be null");
-		Assert.notNull(charset, "'charset' must not be null");
-		int length = source.length();
-		ByteArrayOutputStream bos = new ByteArrayOutputStream(length);
-		boolean changed = false;
-		for (int i = 0; i < length; i++) {
-			int ch = source.charAt(i);
-			if (ch == '%') {
-				if ((i + 2) < length) {
-					char hex1 = source.charAt(i + 1);
-					char hex2 = source.charAt(i + 2);
-					int u = Character.digit(hex1, 16);
-					int l = Character.digit(hex2, 16);
-					if (u == -1 || l == -1) {
-						throw new IllegalArgumentException("Invalid encoded sequence \"" + source.substring(i) + "\"");
-					}
-					bos.write((char) ((u << 4) + l));
-					i += 2;
-					changed = true;
-				}
-				else {
-					throw new IllegalArgumentException("Invalid encoded sequence \"" + source.substring(i) + "\"");
-				}
-			}
-			else {
-				bos.write(ch);
-			}
-		}
-		return (changed ? new String(bos.toByteArray(), charset) : source);
+		return StringUtils.uriDecode(source, Charset.forName(encoding));
 	}
 
 	/**