Replace contains() with indexOf()

Closes gh-11373

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/audit/AuditEvent.java

@@ -95,8 +95,8 @@ public class AuditEvent implements Serializable {
 	private static Map<String, Object> convert(String[] data) {
 		Map<String, Object> result = new HashMap<>();
 		for (String entry : data) {
-			if (entry.contains("=")) {
-				int index = entry.indexOf("=");
+			int index = entry.indexOf("=");
+			if (index != -1) {
 				result.put(entry.substring(0, index), entry.substring(index + 1));
 			}
 			else {

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/Link.java

@@ -39,7 +39,6 @@ public class Link {
 	public Link(String href) {
 		this.href = href;
 		this.templated = href.contains("{");
-
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -303,8 +303,9 @@ public class ServerProperties {
 
 		public String getServletPrefix() {
 			String result = this.path;
-			if (result.contains("*")) {
-				result = result.substring(0, result.indexOf("*"));
+			int index = result.indexOf("*");
+			if (index != -1) {
+				result = result.substring(0, index);
 			}
 			if (result.endsWith("/")) {
 				result = result.substring(0, result.length() - 1);

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/PropertiesLauncher.java

@@ -498,8 +498,8 @@ public class PropertiesLauncher extends Launcher {
 			// If home dir is same as parent archive, no need to add it twice.
 			return null;
 		}
-		if (root.contains("!")) {
-			int index = root.indexOf("!");
+		int index = root.indexOf("!");
+		if (index != -1) {
 			File file = new File(this.home, root.substring(0, index));
 			if (root.startsWith("jar:file:")) {
 				file = new File(root.substring("jar:file:".length(), index));

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/server/DocumentRoot.java

@@ -109,8 +109,9 @@ class DocumentRoot {
 			else {
 				path = location.toURI().getPath();
 			}
-			if (path.contains("!/")) {
-				path = path.substring(0, path.indexOf("!/"));
+			int index = path.indexOf("!/");
+			if (index != -1) {
+				path = path.substring(0, index);
 			}
 			return new File(path);
 		}