Use lambdas for map entry iteration where possible

See gh-12626

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/condition/ConditionsReportEndpoint.java

@@ -123,15 +123,14 @@ public class ConditionsReportEndpoint {
 			this.negativeMatches = new LinkedHashMap<>();
 			this.exclusions = report.getExclusions();
 			this.unconditionalClasses = report.getUnconditionalClasses();
-			for (Map.Entry<String, ConditionAndOutcomes> entry : report
-					.getConditionAndOutcomesBySource().entrySet()) {
-				if (entry.getValue().isFullMatch()) {
-					add(this.positiveMatches, entry.getKey(), entry.getValue());
+			report.getConditionAndOutcomesBySource().forEach((key, value) -> {
+				if (value.isFullMatch()) {
+					add(this.positiveMatches, key, value);
 				}
 				else {
-					add(this.negativeMatches, entry.getKey(), entry.getValue());
+					add(this.negativeMatches, key, value);
 				}
-			}
+			});
 			this.parentId = context.getParent() == null ? null
 					: context.getParent().getId();
 		}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/CompositeHealthIndicatorConfiguration.java

@@ -44,10 +44,7 @@ public abstract class CompositeHealthIndicatorConfiguration<H extends HealthIndi
 		}
 		CompositeHealthIndicator composite = new CompositeHealthIndicator(
 				this.healthAggregator);
-		for (Map.Entry<String, S> entry : beans.entrySet()) {
-			composite.addHealthIndicator(entry.getKey(),
-					createHealthIndicator(entry.getValue()));
-		}
+		beans.forEach((key, value) -> composite.addHealthIndicator(key, createHealthIndicator(value)));
 		return composite;
 	}
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/CompositeReactiveHealthIndicatorConfiguration.java

@@ -43,10 +43,7 @@ public abstract class CompositeReactiveHealthIndicatorConfiguration<H extends Re
 		}
 		CompositeReactiveHealthIndicator composite = new CompositeReactiveHealthIndicator(
 				this.healthAggregator);
-		for (Map.Entry<String, S> entry : beans.entrySet()) {
-			composite.addHealthIndicator(entry.getKey(),
-					createHealthIndicator(entry.getValue()));
-		}
+		beans.forEach((key, value) -> composite.addHealthIndicator(key, createHealthIndicator(value)));
 		return composite;
 	}
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/jdbc/DataSourceHealthIndicatorAutoConfiguration.java

@@ -84,11 +84,11 @@ public class DataSourceHealthIndicatorAutoConfiguration extends
 			return null;
 		}
 		Map<String, DataSource> dataSources = new LinkedHashMap<>();
-		for (Map.Entry<String, DataSource> entry : candidates.entrySet()) {
-			if (!(entry.getValue() instanceof AbstractRoutingDataSource)) {
-				dataSources.put(entry.getKey(), entry.getValue());
+		candidates.forEach((key, value) -> {
+			if (!(value instanceof AbstractRoutingDataSource)) {
+				dataSources.put(key, value);
 			}
-		}
+		});
 		return dataSources;
 	}
 

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/env/EnvironmentEndpoint.java

@@ -120,13 +120,10 @@ public class EnvironmentEndpoint {
 
 	private PropertySummaryDescriptor getPropertySummaryDescriptor(
 			Map<String, PropertyValueDescriptor> descriptors) {
-		for (Map.Entry<String, PropertyValueDescriptor> entry : descriptors.entrySet()) {
-			if (entry.getValue() != null) {
-				return new PropertySummaryDescriptor(entry.getKey(),
-						entry.getValue().getValue());
-			}
-		}
-		return null;
+		return descriptors.entrySet().stream().
+				filter((entry) -> entry.getValue() != null).
+				map((entry) -> new PropertySummaryDescriptor(entry.getKey(), entry.getValue().getValue())).
+				findFirst().orElse(null);
 	}
 
 	private Map<String, PropertyValueDescriptor> getPropertySourceDescriptors(

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

@@ -142,12 +142,11 @@ class AutoConfigurationSorter {
 		public Set<String> getClassesRequestedAfter(String className) {
 			Set<String> rtn = new LinkedHashSet<>();
 			rtn.addAll(get(className).getAfter());
-			for (Map.Entry<String, AutoConfigurationClass> entry : this.classes
-					.entrySet()) {
-				if (entry.getValue().getBefore().contains(className)) {
-					rtn.add(entry.getKey());
+			this.classes.forEach((key, value) -> {
+				if (value.getBefore().contains(className)) {
+					rtn.add(key);
 				}
-			}
+			});
 			return rtn;
 		}
 

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

@@ -74,9 +74,9 @@ class ImportAutoConfigurationImportSelector extends AutoConfigurationImportSelec
 			AnnotationAttributes attributes) {
 		List<String> candidates = new ArrayList<>();
 		Map<Class<?>, List<Annotation>> annotations = getAnnotations(metadata);
-		for (Map.Entry<Class<?>, List<Annotation>> entry : annotations.entrySet()) {
-			collectCandidateConfigurations(entry.getKey(), entry.getValue(), candidates);
-		}
+		annotations.forEach((key, value) -> {
+			collectCandidateConfigurations(key, value, candidates);
+		});
 		return candidates;
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/CacheConfigurations.java

@@ -57,13 +57,10 @@ final class CacheConfigurations {
 	}
 
 	public static CacheType getType(String configurationClassName) {
-		for (Map.Entry<CacheType, Class<?>> entry : MAPPINGS.entrySet()) {
-			if (entry.getValue().getName().equals(configurationClassName)) {
-				return entry.getKey();
-			}
-		}
-		throw new IllegalStateException(
-				"Unknown configuration class " + configurationClassName);
+		return MAPPINGS.entrySet().stream().filter((entry) ->
+					entry.getValue().getName().equals(configurationClassName)).
+				map(Map.Entry::getKey).findFirst().
+				orElseThrow(() -> new IllegalStateException("Unknown configuration class " + configurationClassName));
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/AbstractNestedCondition.java

@@ -159,13 +159,8 @@ public abstract class AbstractNestedCondition extends SpringBootCondition
 
 		public List<ConditionOutcome> getMatchOutcomes() {
 			List<ConditionOutcome> outcomes = new ArrayList<>();
-			for (Map.Entry<AnnotationMetadata, List<Condition>> entry : this.memberConditions
-					.entrySet()) {
-				AnnotationMetadata metadata = entry.getKey();
-				List<Condition> conditions = entry.getValue();
-				outcomes.add(new MemberOutcomes(this.context, metadata, conditions)
-						.getUltimateOutcome());
-			}
+			this.memberConditions.forEach((metadata, conditions) ->
+					outcomes.add(new MemberOutcomes(this.context, metadata, conditions).getUltimateOutcome()));
 			return Collections.unmodifiableList(outcomes);
 		}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/BeanTypeRegistry.java

@@ -24,6 +24,7 @@ import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -112,13 +113,9 @@ final class BeanTypeRegistry implements SmartInitializingSingleton {
 	 */
 	Set<String> getNamesForType(Class<?> type) {
 		updateTypesIfNecessary();
-		Set<String> matches = new LinkedHashSet<>();
-		for (Map.Entry<String, Class<?>> entry : this.beanTypes.entrySet()) {
-			if (entry.getValue() != null && type.isAssignableFrom(entry.getValue())) {
-				matches.add(entry.getKey());
-			}
-		}
-		return matches;
+		return this.beanTypes.entrySet().stream().filter((entry) -> entry.getValue() != null &&
+				type.isAssignableFrom(entry.getValue())).
+				map(Map.Entry::getKey).collect(Collectors.toCollection(LinkedHashSet::new));
 	}
 
 	/**
@@ -132,14 +129,9 @@ final class BeanTypeRegistry implements SmartInitializingSingleton {
 	 */
 	Set<String> getNamesForAnnotation(Class<? extends Annotation> annotation) {
 		updateTypesIfNecessary();
-		Set<String> matches = new LinkedHashSet<>();
-		for (Map.Entry<String, Class<?>> entry : this.beanTypes.entrySet()) {
-			if (entry.getValue() != null && AnnotationUtils
-					.findAnnotation(entry.getValue(), annotation) != null) {
-				matches.add(entry.getKey());
-			}
-		}
-		return matches;
+		return this.beanTypes.entrySet().stream().filter((entry) -> entry.getValue() != null &&
+					AnnotationUtils.findAnnotation(entry.getValue(), annotation) != null).
+				map(Map.Entry::getKey).collect(Collectors.toCollection(LinkedHashSet::new));
 	}
 
 	@Override

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/ConditionEvaluationReport.java

@@ -24,7 +24,6 @@ import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
@@ -112,12 +111,11 @@ public final class ConditionEvaluationReport {
 	 */
 	public Map<String, ConditionAndOutcomes> getConditionAndOutcomesBySource() {
 		if (!this.addedAncestorOutcomes) {
-			for (Map.Entry<String, ConditionAndOutcomes> entry : this.outcomes
-					.entrySet()) {
-				if (!entry.getValue().isFullMatch()) {
-					addNoMatchOutcomeToAncestors(entry.getKey());
+			this.outcomes.forEach((key, value) -> {
+				if (!value.isFullMatch()) {
+					addNoMatchOutcomeToAncestors(key);
 				}
-			}
+			});
 			this.addedAncestorOutcomes = true;
 		}
 		return Collections.unmodifiableMap(this.outcomes);
@@ -125,13 +123,13 @@ public final class ConditionEvaluationReport {
 
 	private void addNoMatchOutcomeToAncestors(String source) {
 		String prefix = source + "$";
-		for (Entry<String, ConditionAndOutcomes> entry : this.outcomes.entrySet()) {
-			if (entry.getKey().startsWith(prefix)) {
+		this.outcomes.forEach((key, value) -> {
+			if (key.startsWith(prefix)) {
 				ConditionOutcome outcome = ConditionOutcome.noMatch(ConditionMessage
 						.forCondition("Ancestor " + source).because("did not match"));
-				entry.getValue().add(ANCESTOR_CONDITION, outcome);
+				value.add(ANCESTOR_CONDITION, outcome);
 			}
-		}
+		});
 	}
 
 	/**
@@ -190,16 +188,15 @@ public final class ConditionEvaluationReport {
 
 	public ConditionEvaluationReport getDelta(ConditionEvaluationReport previousReport) {
 		ConditionEvaluationReport delta = new ConditionEvaluationReport();
-		for (Entry<String, ConditionAndOutcomes> entry : this.outcomes.entrySet()) {
-			ConditionAndOutcomes previous = previousReport.outcomes.get(entry.getKey());
+		this.outcomes.forEach((key, value) -> {
+			ConditionAndOutcomes previous = previousReport.outcomes.get(key);
 			if (previous == null
-					|| previous.isFullMatch() != entry.getValue().isFullMatch()) {
-				entry.getValue()
-						.forEach((conditionAndOutcome) -> delta.recordConditionEvaluation(
-								entry.getKey(), conditionAndOutcome.getCondition(),
+					|| previous.isFullMatch() != value.isFullMatch()) {
+				value.forEach((conditionAndOutcome) -> delta.recordConditionEvaluation(
+								key, conditionAndOutcome.getCondition(),
 								conditionAndOutcome.getOutcome()));
 			}
-		}
+		});
 		List<String> newExclusions = new ArrayList<>(this.exclusions);
 		newExclusions.removeAll(previousReport.getExclusions());
 		delta.recordExclusions(newExclusions);

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnBeanCondition.java

@@ -166,18 +166,18 @@ class OnBeanCondition extends SpringBootCondition implements ConfigurationCondit
 	private void appendMessageForMatches(StringBuilder reason,
 			Map<String, Collection<String>> matches, String description) {
 		if (!matches.isEmpty()) {
-			for (Map.Entry<String, Collection<String>> match : matches.entrySet()) {
+			matches.forEach((key, value) -> {
 				if (reason.length() > 0) {
 					reason.append(" and ");
 				}
 				reason.append("found beans ");
 				reason.append(description);
 				reason.append(" '");
-				reason.append(match.getKey());
+				reason.append(key);
 				reason.append("' ");
 				reason.append(
-						StringUtils.collectionToDelimitedString(match.getValue(), ", "));
-			}
+						StringUtils.collectionToDelimitedString(value, ", "));
+			});
 		}
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnPropertyCondition.java

@@ -20,7 +20,6 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.springframework.boot.autoconfigure.condition.ConditionMessage.Style;
 import org.springframework.context.annotation.Condition;
@@ -69,8 +68,8 @@ class OnPropertyCondition extends SpringBootCondition {
 	private List<AnnotationAttributes> annotationAttributesFromMultiValueMap(
 			MultiValueMap<String, Object> multiValueMap) {
 		List<Map<String, Object>> maps = new ArrayList<>();
-		for (Entry<String, List<Object>> entry : multiValueMap.entrySet()) {
-			for (int i = 0; i < entry.getValue().size(); i++) {
+		multiValueMap.forEach((key, value) -> {
+			for (int i = 0; i < value.size(); i++) {
 				Map<String, Object> map;
 				if (i < maps.size()) {
 					map = maps.get(i);
@@ -79,9 +78,9 @@ class OnPropertyCondition extends SpringBootCondition {
 					map = new HashMap<>();
 					maps.add(map);
 				}
-				map.put(entry.getKey(), entry.getValue().get(i));
+				map.put(key, value.get(i));
 			}
-		}
+		});
 		List<AnnotationAttributes> annotationAttributes = new ArrayList<>(maps.size());
 		for (Map<String, Object> map : maps) {
 			annotationAttributes.add(AnnotationAttributes.fromMap(map));

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/diagnostics/analyzer/NoSuchBeanDefinitionFailureAnalyzer.java

@@ -30,7 +30,6 @@ import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.boot.autoconfigure.condition.ConditionEvaluationReport;
 import org.springframework.boot.autoconfigure.condition.ConditionEvaluationReport.ConditionAndOutcome;
-import org.springframework.boot.autoconfigure.condition.ConditionEvaluationReport.ConditionAndOutcomes;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.diagnostics.FailureAnalysis;
 import org.springframework.boot.diagnostics.analyzer.AbstractInjectionFailureAnalyzer;
@@ -124,10 +123,8 @@ class NoSuchBeanDefinitionFailureAnalyzer
 
 	private void collectReportedConditionOutcomes(NoSuchBeanDefinitionException cause,
 			List<AutoConfigurationResult> results) {
-		for (Map.Entry<String, ConditionAndOutcomes> entry : this.report
-				.getConditionAndOutcomesBySource().entrySet()) {
-			Source source = new Source(entry.getKey());
-			ConditionAndOutcomes conditionAndOutcomes = entry.getValue();
+		this.report.getConditionAndOutcomesBySource().forEach((key, conditionAndOutcomes) -> {
+			Source source = new Source(key);
 			if (!conditionAndOutcomes.isFullMatch()) {
 				BeanMethods methods = new BeanMethods(source, cause);
 				for (ConditionAndOutcome conditionAndOutcome : conditionAndOutcomes) {
@@ -139,7 +136,7 @@ class NoSuchBeanDefinitionFailureAnalyzer
 					}
 				}
 			}
-		}
+		});
 	}
 
 	private void collectExcludedAutoConfiguration(NoSuchBeanDefinitionException cause,

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jersey/JerseyAutoConfiguration.java

@@ -19,7 +19,6 @@ package org.springframework.boot.autoconfigure.jersey;
 import java.util.Arrays;
 import java.util.EnumSet;
 import java.util.List;
-import java.util.Map.Entry;
 
 import javax.annotation.PostConstruct;
 import javax.servlet.DispatcherType;
@@ -181,9 +180,7 @@ public class JerseyAutoConfiguration implements ServletContextAware {
 	}
 
 	private void addInitParameters(DynamicRegistrationBean<?> registration) {
-		for (Entry<String, String> entry : this.jersey.getInit().entrySet()) {
-			registration.addInitParameter(entry.getKey(), entry.getValue());
-		}
+		this.jersey.getInit().forEach(registration::addInitParameter);
 	}
 
 	private static String findApplicationPath(ApplicationPath annotation) {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/SessionStoreMappings.java

@@ -19,6 +19,7 @@ package org.springframework.boot.autoconfigure.session;
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.Map;
+import java.util.Objects;
 
 import org.springframework.boot.WebApplicationType;
 import org.springframework.util.Assert;
@@ -82,18 +83,12 @@ final class SessionStoreMappings {
 
 	static StoreType getType(WebApplicationType webApplicationType,
 			String configurationClassName) {
-		for (Map.Entry<StoreType, Map<WebApplicationType, Class<?>>> storeEntry : MAPPINGS
-				.entrySet()) {
-			for (Map.Entry<WebApplicationType, Class<?>> entry : storeEntry.getValue()
-					.entrySet()) {
-				if (entry.getKey() == webApplicationType
-						&& entry.getValue().getName().equals(configurationClassName)) {
-					return storeEntry.getKey();
-				}
-			}
-		}
-		throw new IllegalStateException(
-				"Unknown configuration class " + configurationClassName);
+		return MAPPINGS.entrySet().stream().map(entry ->
+				entry.getValue().entrySet().stream().filter(webAppEntry ->  webAppEntry.getKey() == webApplicationType
+						&& webAppEntry.getValue().getName().equals(configurationClassName)).
+						map(webAppEntry -> entry.getKey()).findFirst().orElse(null)).filter(Objects::nonNull).
+				findFirst().orElseThrow(() ->
+					new IllegalStateException("Unknown configuration class " + configurationClassName));
 	}
 
 }

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

@@ -24,7 +24,6 @@ import java.util.Collections;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Optional;
 
 import javax.servlet.Servlet;
@@ -236,9 +235,7 @@ public class WebMvcAutoConfiguration {
 			}
 			Map<String, MediaType> mediaTypes = this.mvcProperties.getContentnegotiation()
 					.getMediaTypes();
-			for (Entry<String, MediaType> mediaType : mediaTypes.entrySet()) {
-				configurer.mediaType(mediaType.getKey(), mediaType.getValue());
-			}
+			mediaTypes.forEach(configurer::mediaType);
 		}
 
 		@Bean

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/webservices/WebServicesAutoConfiguration.java

@@ -19,7 +19,6 @@ package org.springframework.boot.autoconfigure.webservices;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
@@ -83,9 +82,7 @@ public class WebServicesAutoConfiguration {
 				servlet, urlMapping);
 		WebServicesProperties.Servlet servletProperties = this.properties.getServlet();
 		registration.setLoadOnStartup(servletProperties.getLoadOnStartup());
-		for (Map.Entry<String, String> entry : servletProperties.getInit().entrySet()) {
-			registration.addInitParameter(entry.getKey(), entry.getValue());
-		}
+		servletProperties.getInit().forEach(registration::addInitParameter);
 		return registration;
 	}
 

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/command/init/ProjectGenerationRequest.java

@@ -20,7 +20,6 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
@@ -423,14 +422,7 @@ class ProjectGenerationRequest {
 
 	private static void filter(Map<String, ProjectType> projects, String tag,
 			String tagValue) {
-		for (Iterator<Map.Entry<String, ProjectType>> it = projects.entrySet()
-				.iterator(); it.hasNext();) {
-			Map.Entry<String, ProjectType> entry = it.next();
-			String value = entry.getValue().getTags().get(tag);
-			if (!tagValue.equals(value)) {
-				it.remove();
-			}
-		}
+		projects.entrySet().removeIf((entry) -> !tagValue.equals(entry.getValue().getTags().get(tag)));
 	}
 
 }

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/compiler/AnnotatedNodeASTTransformation.java

@@ -19,7 +19,6 @@ package org.springframework.boot.cli.compiler;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 import org.codehaus.groovy.ast.ASTNode;
@@ -68,14 +67,8 @@ public abstract class AnnotatedNodeASTTransformation implements ASTTransformatio
 				for (ImportNode importNode : module.getStarImports()) {
 					visitAnnotatedNode(importNode, annotationNodes);
 				}
-				for (Map.Entry<String, ImportNode> entry : module.getStaticImports()
-						.entrySet()) {
-					visitAnnotatedNode(entry.getValue(), annotationNodes);
-				}
-				for (Map.Entry<String, ImportNode> entry : module.getStaticStarImports()
-						.entrySet()) {
-					visitAnnotatedNode(entry.getValue(), annotationNodes);
-				}
+				module.getStaticImports().forEach((key, value) -> visitAnnotatedNode(value, annotationNodes));
+				module.getStaticStarImports().forEach((key, value) -> visitAnnotatedNode(value, annotationNodes));
 				for (ClassNode classNode : module.getClasses()) {
 					visitAnnotatedNode(classNode, annotationNodes);
 					classNode.visitContents(classVisitor);

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/settings/DevToolsSettings.java

@@ -63,13 +63,13 @@ public class DevToolsSettings {
 
 	private Map<String, Pattern> getPatterns(Map<?, ?> properties, String prefix) {
 		Map<String, Pattern> patterns = new LinkedHashMap<>();
-		for (Map.Entry<?, ?> entry : properties.entrySet()) {
-			String name = String.valueOf(entry.getKey());
+		properties.forEach((key, value) -> {
+			String name = String.valueOf(key);
 			if (name.startsWith(prefix)) {
-				Pattern pattern = Pattern.compile((String) entry.getValue());
+				Pattern pattern = Pattern.compile((String) value);
 				patterns.put(name, pattern);
 			}
-		}
+		});
 		return patterns;
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-autoconfigure-processor/src/main/java/org/springframework/boot/autoconfigureprocessor/AutoConfigureAnnotationProcessor.java

@@ -18,13 +18,13 @@ package org.springframework.boot.autoconfigureprocessor;
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import javax.annotation.processing.AbstractProcessor;
 import javax.annotation.processing.RoundEnvironment;
@@ -34,7 +34,6 @@ import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
-import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeMirror;
@@ -158,23 +157,19 @@ public class AutoConfigureAnnotationProcessor extends AbstractProcessor {
 
 	@SuppressWarnings("unchecked")
 	private List<Object> getValues(AnnotationMirror annotation) {
-		List<Object> result = new ArrayList<>();
-		for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotation
-				.getElementValues().entrySet()) {
+		return annotation .getElementValues().entrySet().stream().filter(entry -> {
 			String attributeName = entry.getKey().getSimpleName().toString();
-			if ("name".equals(attributeName) || "value".equals(attributeName)) {
-				Object value = entry.getValue().getValue();
-				if (value instanceof List) {
-					for (AnnotationValue annotationValue : (List<AnnotationValue>) value) {
-						result.add(processValue(annotationValue.getValue()));
-					}
-				}
-				else {
-					result.add(processValue(value));
-				}
+			return "name".equals(attributeName) || "value".equals(attributeName);
+		}).map((entry) -> {
+			Object value = entry.getValue().getValue();
+			if (value instanceof List) {
+				return ((List<AnnotationValue>) value).stream().
+						map(annotationValue -> processValue(annotationValue.getValue())).collect(Collectors.toList());
 			}
-		}
-		return result;
+			else {
+				return Collections.singletonList(processValue(value));
+			}
+		}).flatMap(List::stream).collect(Collectors.toList());
 	}
 
 	private Object processValue(Object value) {

spring-boot-project/spring-boot-tools/spring-boot-configuration-metadata/src/main/java/org/springframework/boot/configurationmetadata/SimpleConfigurationMetadataRepository.java

@@ -93,17 +93,9 @@ public class SimpleConfigurationMetadataRepository
 			}
 			else {
 				// Merge properties
-				for (Map.Entry<String, ConfigurationMetadataProperty> entry : group
-						.getProperties().entrySet()) {
-					putIfAbsent(existingGroup.getProperties(), entry.getKey(),
-							entry.getValue());
-				}
+				group.getProperties().forEach((key, value) -> putIfAbsent(existingGroup.getProperties(), key, value));
 				// Merge sources
-				for (Map.Entry<String, ConfigurationMetadataSource> entry : group
-						.getSources().entrySet()) {
-					putIfAbsent(existingGroup.getSources(), entry.getKey(),
-							entry.getValue());
-				}
+				group.getSources().forEach((key, value) -> putIfAbsent(existingGroup.getSources(), key, value));
 			}
 		}
 

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessor.java

@@ -36,7 +36,6 @@ import javax.annotation.processing.RoundEnvironment;
 import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.AnnotationMirror;
-import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
 import javax.lang.model.element.ExecutableElement;
@@ -282,10 +281,7 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 	private void processSimpleTypes(String prefix, TypeElement element,
 			ExecutableElement source, TypeElementMembers members,
 			Map<String, Object> fieldValues) {
-		for (Map.Entry<String, ExecutableElement> entry : members.getPublicGetters()
-				.entrySet()) {
-			String name = entry.getKey();
-			ExecutableElement getter = entry.getValue();
+		members.getPublicGetters().forEach((name, getter) -> {
 			TypeMirror returnType = getter.getReturnType();
 			ExecutableElement setter = members.getPublicSetter(name, returnType);
 			VariableElement field = members.getFields().get(name);
@@ -305,7 +301,7 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 						dataType, sourceType, null, description, defaultValue,
 						(deprecated ? getItemDeprecation(getter) : null)));
 			}
-		}
+		});
 	}
 
 	private ItemDeprecation getItemDeprecation(ExecutableElement getter) {
@@ -325,11 +321,9 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 	private void processSimpleLombokTypes(String prefix, TypeElement element,
 			ExecutableElement source, TypeElementMembers members,
 			Map<String, Object> fieldValues) {
-		for (Map.Entry<String, VariableElement> entry : members.getFields().entrySet()) {
-			String name = entry.getKey();
-			VariableElement field = entry.getValue();
+		members.getFields().forEach((name, field) -> {
 			if (!isLombokField(field, element)) {
-				continue;
+				return;
 			}
 			TypeMirror returnType = field.asType();
 			Element returnTypeElement = this.processingEnv.getTypeUtils()
@@ -348,32 +342,27 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 						dataType, sourceType, null, description, defaultValue,
 						(deprecated ? new ItemDeprecation() : null)));
 			}
-		}
+		});
 	}
 
 	private void processNestedTypes(String prefix, TypeElement element,
 			ExecutableElement source, TypeElementMembers members) {
-		for (Map.Entry<String, ExecutableElement> entry : members.getPublicGetters()
-				.entrySet()) {
-			String name = entry.getKey();
-			ExecutableElement getter = entry.getValue();
+		members.getPublicGetters().forEach((name, getter) -> {
 			VariableElement field = members.getFields().get(name);
 			processNestedType(prefix, element, source, name, getter, field,
 					getter.getReturnType());
-		}
+		});
 	}
 
 	private void processNestedLombokTypes(String prefix, TypeElement element,
 			ExecutableElement source, TypeElementMembers members) {
-		for (Map.Entry<String, VariableElement> entry : members.getFields().entrySet()) {
-			String name = entry.getKey();
-			VariableElement field = entry.getValue();
+		members.getFields().forEach((name, field) -> {
 			if (isLombokField(field, element)) {
 				ExecutableElement getter = members.getPublicGetter(name, field.asType());
 				processNestedType(prefix, element, source, name, getter, field,
 						field.asType());
 			}
-		}
+		});
 	}
 
 	private boolean isLombokField(VariableElement field, TypeElement element) {
@@ -544,11 +533,8 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 
 	private Map<String, Object> getAnnotationElementValues(AnnotationMirror annotation) {
 		Map<String, Object> values = new LinkedHashMap<>();
-		for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotation
-				.getElementValues().entrySet()) {
-			values.put(entry.getKey().getSimpleName().toString(),
-					entry.getValue().getValue());
-		}
+		annotation.getElementValues().forEach((key, value) ->
+				values.put(key.getSimpleName().toString(), value.getValue()));
 		return values;
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/TypeElementMembers.java

@@ -78,13 +78,11 @@ class TypeElementMembers {
 			processField(field);
 		}
 		try {
-			Map<String, Object> fieldValues = this.fieldValuesParser
-					.getFieldValues(element);
-			for (Map.Entry<String, Object> entry : fieldValues.entrySet()) {
-				if (!this.fieldValues.containsKey(entry.getKey())) {
-					this.fieldValues.put(entry.getKey(), entry.getValue());
+			this.fieldValuesParser.getFieldValues(element).forEach((key, value) -> {
+				if (!this.fieldValues.containsKey(key)) {
+					this.fieldValues.put(key, value);
 				}
-			}
+			});
 		}
 		catch (Exception ex) {
 			// continue

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/TypeUtils.java

@@ -62,9 +62,7 @@ class TypeUtils {
 
 	static {
 		Map<String, TypeKind> primitives = new HashMap<>();
-		for (Map.Entry<TypeKind, Class<?>> entry : PRIMITIVE_WRAPPERS.entrySet()) {
-			primitives.put(entry.getValue().getName(), entry.getKey());
-		}
+		PRIMITIVE_WRAPPERS.forEach((key, value) -> primitives.put(value.getName(), key));
 		WRAPPER_TO_PRIMITIVE = primitives;
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/buildinfo/BuildInfo.java

@@ -20,7 +20,6 @@ import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.gradle.api.Action;
 import org.gradle.api.Project;
@@ -110,9 +109,7 @@ public class BuildInfo extends ConventionTask {
 
 	private Map<String, String> coerceToStringValues(Map<String, Object> input) {
 		Map<String, String> output = new HashMap<>();
-		for (Entry<String, Object> entry : input.entrySet()) {
-			output.put(entry.getKey(), entry.getValue().toString());
-		}
+		input.forEach((key, value) -> output.put(key, value.toString()));
 		return output;
 	}
 

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

@@ -22,7 +22,6 @@ import java.io.IOException;
 import java.time.Instant;
 import java.time.format.DateTimeFormatter;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Properties;
 
 /**
@@ -79,10 +78,7 @@ public final class BuildPropertiesWriter {
 					DateTimeFormatter.ISO_INSTANT.format(project.getTime()));
 		}
 		if (project.getAdditionalProperties() != null) {
-			for (Map.Entry<String, String> entry : project.getAdditionalProperties()
-					.entrySet()) {
-				properties.put("build." + entry.getKey(), entry.getValue());
-			}
+			project.getAdditionalProperties().forEach((key, value) -> properties.put("build." + key, value));
 		}
 		return properties;
 	}
@@ -118,11 +114,11 @@ public final class BuildPropertiesWriter {
 		private static void validateAdditionalProperties(
 				Map<String, String> additionalProperties) {
 			if (additionalProperties != null) {
-				for (Entry<String, String> property : additionalProperties.entrySet()) {
-					if (property.getValue() == null) {
-						throw new NullAdditionalPropertyValueException(property.getKey());
+				additionalProperties.forEach((key, value) -> {
+					if (value == null) {
+						throw new NullAdditionalPropertyValueException(key);
 					}
-				}
+				});
 			}
 		}
 

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/PropertiesMergingResourceTransformer.java

@@ -19,7 +19,6 @@ package org.springframework.boot.maven;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
-import java.util.Map.Entry;
 import java.util.Properties;
 import java.util.jar.JarEntry;
 import java.util.jar.JarOutputStream;
@@ -64,13 +63,13 @@ public class PropertiesMergingResourceTransformer implements ResourceTransformer
 		Properties properties = new Properties();
 		properties.load(is);
 		is.close();
-		for (Entry<Object, Object> entry : properties.entrySet()) {
-			String name = (String) entry.getKey();
-			String value = (String) entry.getValue();
+		properties.forEach((key, valueObject) -> {
+			String name = (String) key;
+			String value = (String) valueObject;
 			String existing = this.data.getProperty(name);
 			this.data.setProperty(name,
 					existing == null ? value : existing + "," + value);
-		}
+		});
 	}
 
 	@Override

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/Verify.java

@@ -140,13 +140,10 @@ public final class Verify {
 		}
 
 		private ZipEntry getEntryStartingWith(String entryName) {
-			for (Map.Entry<String, ZipEntry> entry : this.content.entrySet()) {
-				if (entry.getKey().startsWith(entryName)) {
-					return entry.getValue();
-				}
-			}
-			throw new IllegalStateException(
-					"Unable to find entry starting with " + entryName);
+			return this.content.entrySet().stream().
+					filter(entry -> entry.getKey().startsWith(entryName)).
+					map(Map.Entry::getValue).findFirst().orElseThrow(() ->
+						new IllegalStateException("Unable to find entry starting with " + entryName));
 		}
 
 		public boolean hasEntry(String entry) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/LoggingSystem.java

@@ -156,12 +156,10 @@ public abstract class LoggingSystem {
 			}
 			return get(classLoader, loggingSystem);
 		}
-		for (Map.Entry<String, String> entry : SYSTEMS.entrySet()) {
-			if (ClassUtils.isPresent(entry.getKey(), classLoader)) {
-				return get(classLoader, entry.getValue());
-			}
-		}
-		throw new IllegalStateException("No suitable logging system located");
+		return SYSTEMS.entrySet().stream().
+				filter((entry) -> ClassUtils.isPresent(entry.getKey(), classLoader)).
+				map(entry -> get(classLoader, entry.getValue())).
+				findFirst().orElseThrow(() -> new IllegalStateException("No suitable logging system located"));
 	}
 
 	private static LoggingSystem get(ClassLoader classLoader, String loggingSystemClass) {