Refine use of substring operations

Closes gh-25445

Author: XenoAmess

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJAdviceParameterNameDiscoverer.java

@@ -648,7 +648,7 @@ private PointcutBody getPointcutBody(String[] tokens, int startIndex) {
 				}
 
 				if (tokens[currentIndex].endsWith(")")) {
-					sb.append(tokens[currentIndex].substring(0, tokens[currentIndex].length() - 1));
+					sb.append(tokens[currentIndex], 0, tokens[currentIndex].length() - 1);
 					return new PointcutBody(numTokensConsumed, sb.toString().trim());
 				}
 

spring-beans/src/main/java/org/springframework/beans/PropertyEditorRegistrySupport.java

@@ -513,7 +513,7 @@ private void addStrippedPropertyPaths(List<String> strippedPaths, String nestedP
 			if (endIndex != -1) {
 				String prefix = propertyPath.substring(0, startIndex);
 				String key = propertyPath.substring(startIndex, endIndex + 1);
-				String suffix = propertyPath.substring(endIndex + 1, propertyPath.length());
+				String suffix = propertyPath.substring(endIndex + 1);
 				// Strip the first key.
 				strippedPaths.add(nestedPath + prefix + suffix);
 				// Search for further keys to strip, with the first key stripped.

spring-context/src/main/java/org/springframework/scheduling/config/TaskExecutorFactoryBean.java

@@ -107,7 +107,7 @@ private void determinePoolSizeRange(ThreadPoolTaskExecutor executor) {
 				int separatorIndex = this.poolSize.indexOf('-');
 				if (separatorIndex != -1) {
 					corePoolSize = Integer.parseInt(this.poolSize.substring(0, separatorIndex));
-					maxPoolSize = Integer.parseInt(this.poolSize.substring(separatorIndex + 1, this.poolSize.length()));
+					maxPoolSize = Integer.parseInt(this.poolSize.substring(separatorIndex + 1));
 					if (corePoolSize > maxPoolSize) {
 						throw new IllegalArgumentException(
 								"Lower bound of pool-size range must not exceed the upper bound");

spring-jms/src/main/java/org/springframework/jms/listener/DefaultMessageListenerContainer.java

@@ -310,7 +310,7 @@ public void setConcurrency(String concurrency) {
 			int separatorIndex = concurrency.indexOf('-');
 			if (separatorIndex != -1) {
 				setConcurrentConsumers(Integer.parseInt(concurrency.substring(0, separatorIndex)));
-				setMaxConcurrentConsumers(Integer.parseInt(concurrency.substring(separatorIndex + 1, concurrency.length())));
+				setMaxConcurrentConsumers(Integer.parseInt(concurrency.substring(separatorIndex + 1)));
 			}
 			else {
 				setConcurrentConsumers(1);

spring-jms/src/main/java/org/springframework/jms/listener/SimpleMessageListenerContainer.java

@@ -126,7 +126,7 @@ public void setConcurrency(String concurrency) {
 		try {
 			int separatorIndex = concurrency.indexOf('-');
 			if (separatorIndex != -1) {
-				setConcurrentConsumers(Integer.parseInt(concurrency.substring(separatorIndex + 1, concurrency.length())));
+				setConcurrentConsumers(Integer.parseInt(concurrency.substring(separatorIndex + 1)));
 			}
 			else {
 				setConcurrentConsumers(Integer.parseInt(concurrency));

spring-jms/src/main/java/org/springframework/jms/listener/endpoint/JmsActivationSpecConfig.java

@@ -226,7 +226,7 @@ public void setConcurrency(String concurrency) {
 		try {
 			int separatorIndex = concurrency.indexOf('-');
 			if (separatorIndex != -1) {
-				setMaxConcurrency(Integer.parseInt(concurrency.substring(separatorIndex + 1, concurrency.length())));
+				setMaxConcurrency(Integer.parseInt(concurrency.substring(separatorIndex + 1)));
 			}
 			else {
 				setMaxConcurrency(Integer.parseInt(concurrency));

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompDecoder.java

@@ -269,7 +269,7 @@ private String unescape(String inString) {
 		int index = inString.indexOf('\\');
 
 		while (index >= 0) {
-			sb.append(inString.substring(pos, index));
+			sb.append(inString, pos, index);
 			if (index + 1 >= inString.length()) {
 				throw new StompConversionException("Illegal escape sequence at index " + index + ": " + inString);
 			}

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompEncoder.java

@@ -212,7 +212,7 @@ else if (sb != null){
 	private StringBuilder getStringBuilder(@Nullable StringBuilder sb, String inString, int i) {
 		if (sb == null) {
 			sb = new StringBuilder(inString.length());
-			sb.append(inString.substring(0, i));
+			sb.append(inString, 0, i);
 		}
 		return sb;
 	}

spring-test/src/main/java/org/springframework/test/web/servlet/setup/PatternMappingFilterProxy.java

@@ -71,7 +71,7 @@ public PatternMappingFilterProxy(Filter delegate, String... urlPatterns) {
 	private void addUrlPattern(String urlPattern) {
 		Assert.notNull(urlPattern, "Found null URL Pattern");
 		if (urlPattern.startsWith(EXTENSION_MAPPING_PATTERN)) {
-			this.endsWithMatches.add(urlPattern.substring(1, urlPattern.length()));
+			this.endsWithMatches.add(urlPattern.substring(1));
 		}
 		else if (urlPattern.equals(PATH_MAPPING_PATTERN)) {
 			this.startsWithMatches.add("");

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

@@ -225,7 +225,7 @@ else if (c == '}') {
 								throw new IllegalArgumentException(
 										"No custom regular expression specified after ':' in \"" + variable + "\"");
 							}
-							String regex = variable.substring(idx + 1, variable.length());
+							String regex = variable.substring(idx + 1);
 							pattern.append('(');
 							pattern.append(regex);
 							pattern.append(')');

spring-webflux/src/main/java/org/springframework/web/reactive/result/view/RedirectView.java

@@ -245,12 +245,12 @@ protected StringBuilder expandTargetUrlTemplate(String targetUrl,
 			String name = matcher.group(1);
 			Object value = (model.containsKey(name) ? model.get(name) : uriVariables.get(name));
 			Assert.notNull(value, () -> "No value for URI variable '" + name + "'");
-			result.append(targetUrl.substring(endLastMatch, matcher.start()));
+			result.append(targetUrl, endLastMatch, matcher.start());
 			result.append(encodeUriVariable(value.toString()));
 			endLastMatch = matcher.end();
 			found = matcher.find();
 		}
-		result.append(targetUrl.substring(endLastMatch, targetUrl.length()));
+		result.append(targetUrl.substring(endLastMatch));
 		return result;
 	}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/tags/UrlTag.java

@@ -278,7 +278,7 @@ String createUrl() throws JspException {
 			}
 			else {
 				if (this.context.endsWith("/")) {
-					url.append(this.context.substring(0, this.context.length() - 1));
+					url.append(this.context, 0, this.context.length() - 1);
 				}
 				else {
 					url.append(this.context);

spring-webmvc/src/main/java/org/springframework/web/servlet/view/RedirectView.java

@@ -386,7 +386,7 @@ protected StringBuilder replaceUriTemplateVariables(
 			if (value == null) {
 				throw new IllegalArgumentException("Model has no value for key '" + name + "'");
 			}
-			result.append(targetUrl.substring(endLastMatch, matcher.start()));
+			result.append(targetUrl, endLastMatch, matcher.start());
 			result.append(UriUtils.encodePathSegment(value.toString(), encodingScheme));
 			endLastMatch = matcher.end();
 		}

spring-websocket/src/main/java/org/springframework/web/socket/WebSocketExtension.java

@@ -160,7 +160,7 @@ private static WebSocketExtension parseExtension(String extension) {
 				int eqIndex = parameter.indexOf('=');
 				if (eqIndex != -1) {
 					String attribute = parameter.substring(0, eqIndex);
-					String value = parameter.substring(eqIndex + 1, parameter.length());
+					String value = parameter.substring(eqIndex + 1);
 					parameters.put(attribute, value);
 				}
 			}