Polishing: fix a number of compiler warnings reported by Eclipse

spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/metadata/ConfigurationMetadata.java

@@ -179,7 +179,7 @@ public class ConfigurationMetadata {
 		return first + "-" + second;
 	}
 
-	private static <T extends Comparable> List<T> flattenValues(MultiValueMap<?, T> map) {
+	private static <T extends Comparable<T>> List<T> flattenValues(MultiValueMap<?, T> map) {
 		List<T> content = new ArrayList<T>();
 		for (List<T> values : map.values()) {
 			content.addAll(values);

spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/lombok/LombokSimpleDataProperties.java

@@ -30,6 +30,7 @@ import lombok.Data;
  */
 @Data
 @ConfigurationProperties(prefix = "data")
+@SuppressWarnings("unused")
 public class LombokSimpleDataProperties {
 
 	private final String id = "super-id";

spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/lombok/LombokSimpleProperties.java

@@ -32,6 +32,7 @@ import lombok.Setter;
 @Getter
 @Setter
 @ConfigurationProperties(prefix = "simple")
+@SuppressWarnings("unused")
 public class LombokSimpleProperties {
 
 	private final String id = "super-id";

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/data/RandomAccessDataFile.java

@@ -243,6 +243,7 @@ public class RandomAccessDataFile implements RandomAccessData {
 			this.files = new ConcurrentLinkedQueue<RandomAccessFile>();
 		}
 
+		@SuppressWarnings("resource")
 		public RandomAccessFile acquire() throws IOException {
 			try {
 				this.available.acquire();