Use Collections.addAll(...) instead of for loops

Replace various for loops which add items to collections with calls
to Collections.addAll(...).

Fixes spring-projectsgh-2277

Author: philwebb

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/reader/CompositeMetricReader.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.actuate.metrics.reader;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.springframework.boot.actuate.metrics.Metric;
@@ -31,9 +32,7 @@ public class CompositeMetricReader implements MetricReader {
 	private final List<MetricReader> readers = new ArrayList<MetricReader>();
 
 	public CompositeMetricReader(MetricReader... readers) {
-		for (MetricReader reader : readers) {
-			this.readers.add(reader);
-		}
+		Collections.addAll(this.readers, readers);
 	}
 
 	@Override

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/writer/CompositeMetricWriter.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.actuate.metrics.writer;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.springframework.boot.actuate.metrics.Metric;
@@ -32,9 +33,7 @@ public class CompositeMetricWriter implements MetricWriter {
 	private final List<MetricWriter> writers = new ArrayList<MetricWriter>();
 
 	public CompositeMetricWriter(MetricWriter... writers) {
-		for (MetricWriter writer : writers) {
-			this.writers.add(writer);
-		}
+		Collections.addAll(this.writers, writers);
 	}
 
 	public CompositeMetricWriter(List<MetricWriter> writers) {

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

@@ -241,9 +241,7 @@ private void collect(MultiValueMap<String, Object> attributes, String key,
 				List<String> destination) {
 			List<String[]> valueList = (List) attributes.get(key);
 			for (String[] valueArray : valueList) {
-				for (String value : valueArray) {
-					destination.add(value);
-				}
+				Collections.addAll(destination, valueArray);
 			}
 		}
 

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

@@ -19,6 +19,7 @@
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
@@ -92,9 +93,7 @@ protected ClassLoader createClassLoader(URL[] urls) throws Exception {
 				}
 			}
 		}
-		for (URL url : urls) {
-			copy.add(url);
-		}
+		Collections.addAll(copy, urls);
 		return super.createClassLoader(copy.toArray(new URL[copy.size()]));
 	}
 

spring-boot/src/main/java/org/springframework/boot/context/embedded/FilterRegistrationBean.java

@@ -18,6 +18,7 @@
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.EnumSet;
 import java.util.LinkedHashSet;
 import java.util.Set;
@@ -91,9 +92,7 @@ public FilterRegistrationBean(Filter filter,
 		Assert.notNull(servletRegistrationBeans,
 				"ServletRegistrationBeans must not be null");
 		this.filter = filter;
-		for (ServletRegistrationBean servletRegistrationBean : servletRegistrationBeans) {
-			this.servletRegistrationBeans.add(servletRegistrationBean);
-		}
+		Collections.addAll(this.servletRegistrationBeans, servletRegistrationBeans);
 	}
 
 	/**
@@ -143,9 +142,7 @@ public void addServletRegistrationBeans(
 			ServletRegistrationBean... servletRegistrationBeans) {
 		Assert.notNull(servletRegistrationBeans,
 				"ServletRegistrationBeans must not be null");
-		for (ServletRegistrationBean servletRegistrationBean : servletRegistrationBeans) {
-			this.servletRegistrationBeans.add(servletRegistrationBean);
-		}
+		Collections.addAll(this.servletRegistrationBeans, servletRegistrationBeans);
 	}
 
 	/**
@@ -205,9 +202,7 @@ public Collection<String> getUrlPatterns() {
 	 */
 	public void addUrlPatterns(String... urlPatterns) {
 		Assert.notNull(urlPatterns, "UrlPatterns must not be null");
-		for (String urlPattern : urlPatterns) {
-			this.urlPatterns.add(urlPattern);
-		}
+		Collections.addAll(this.urlPatterns, urlPatterns);
 	}
 
 	/**

spring-boot/src/main/java/org/springframework/boot/yaml/SpringProfileDocumentMatcher.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.yaml;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Properties;
 
@@ -47,9 +48,7 @@ public SpringProfileDocumentMatcher(String... profiles) {
 	public void addActiveProfiles(String... profiles) {
 		LinkedHashSet<String> set = new LinkedHashSet<String>(
 				Arrays.asList(this.activeProfiles));
-		for (String profile : profiles) {
-			set.add(profile);
-		}
+		Collections.addAll(set, profiles);
 		this.activeProfiles = set.toArray(new String[set.size()]);
 	}