Remove unnecessary iteration over headers

The use of LinkedCaseInsensitiveMap, going back to 3.0, makes it
unnecessary to iterate over keys which can cause
ConcurrentModificationException.

Closes gh-23460

spring-test/src/main/java/org/springframework/mock/web/HeaderValueHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -91,8 +91,11 @@ class HeaderValueHolder {
 	 * @param headers the Map of header names to HeaderValueHolders
 	 * @param name the name of the desired header
 	 * @return the corresponding HeaderValueHolder, or {@code null} if none found
+	 * @deprecated as of 5.1.10 in favor of using
+	 * {@link org.springframework.util.LinkedCaseInsensitiveMap}.
 	 */
 	@Nullable
+	@Deprecated
 	public static HeaderValueHolder getByName(Map<String, HeaderValueHolder> headers, String name) {
 		Assert.notNull(name, "Header name must not be null");
 		for (String headerName : headers.keySet()) {

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletRequest.java

@@ -1038,7 +1038,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	}
 
 	private void doAddHeaderValue(String name, @Nullable Object value, boolean replace) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Assert.notNull(value, "Header value must not be null");
 		if (header == null || replace) {
 			header = new HeaderValueHolder();
@@ -1078,7 +1078,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	 */
 	@Override
 	public long getDateHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Object value = (header != null ? header.getValue() : null);
 		if (value instanceof Date) {
 			return ((Date) value).getTime();
@@ -1115,13 +1115,13 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	@Override
 	@Nullable
 	public String getHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getStringValue() : null);
 	}
 
 	@Override
 	public Enumeration<String> getHeaders(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return Collections.enumeration(header != null ? header.getStringValues() : new LinkedList<>());
 	}
 
@@ -1132,7 +1132,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public int getIntHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Object value = (header != null ? header.getValue() : null);
 		if (value instanceof Number) {
 			return ((Number) value).intValue();

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -380,7 +380,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 
 	@Override
 	public boolean containsHeader(String name) {
-		return (HeaderValueHolder.getByName(this.headers, name) != null);
+		return (this.headers.get(name) != null);
 	}
 
 	/**
@@ -405,7 +405,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	@Override
 	@Nullable
 	public String getHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getStringValue() : null);
 	}
 
@@ -419,7 +419,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 */
 	@Override
 	public List<String> getHeaders(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		if (header != null) {
 			return header.getStringValues();
 		}
@@ -436,7 +436,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 */
 	@Nullable
 	public Object getHeaderValue(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getValue() : null);
 	}
 
@@ -446,7 +446,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @return the associated header values, or an empty List if none
 	 */
 	public List<Object> getHeaderValues(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		if (header != null) {
 			return header.getValues();
 		}
@@ -614,7 +614,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	private void doAddHeaderValue(String name, Object value, boolean replace) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Assert.notNull(value, "Header value must not be null");
 		if (header == null) {
 			header = new HeaderValueHolder();

spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletRequest.java

@@ -1038,7 +1038,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	}
 
 	private void doAddHeaderValue(String name, @Nullable Object value, boolean replace) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Assert.notNull(value, "Header value must not be null");
 		if (header == null || replace) {
 			header = new HeaderValueHolder();
@@ -1078,7 +1078,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	 */
 	@Override
 	public long getDateHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Object value = (header != null ? header.getValue() : null);
 		if (value instanceof Date) {
 			return ((Date) value).getTime();
@@ -1115,13 +1115,13 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	@Override
 	@Nullable
 	public String getHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getStringValue() : null);
 	}
 
 	@Override
 	public Enumeration<String> getHeaders(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return Collections.enumeration(header != null ? header.getStringValues() : new LinkedList<>());
 	}
 
@@ -1132,7 +1132,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public int getIntHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Object value = (header != null ? header.getValue() : null);
 		if (value instanceof Number) {
 			return ((Number) value).intValue();

spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -380,7 +380,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 
 	@Override
 	public boolean containsHeader(String name) {
-		return (HeaderValueHolder.getByName(this.headers, name) != null);
+		return (this.headers.get(name) != null);
 	}
 
 	/**
@@ -405,7 +405,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	@Override
 	@Nullable
 	public String getHeader(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getStringValue() : null);
 	}
 
@@ -419,7 +419,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 */
 	@Override
 	public List<String> getHeaders(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		if (header != null) {
 			return header.getStringValues();
 		}
@@ -436,7 +436,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 */
 	@Nullable
 	public Object getHeaderValue(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		return (header != null ? header.getValue() : null);
 	}
 
@@ -446,7 +446,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @return the associated header values, or an empty List if none
 	 */
 	public List<Object> getHeaderValues(String name) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		if (header != null) {
 			return header.getValues();
 		}
@@ -614,7 +614,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	private void doAddHeaderValue(String name, Object value, boolean replace) {
-		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
+		HeaderValueHolder header = this.headers.get(name);
 		Assert.notNull(value, "Header value must not be null");
 		if (header == null) {
 			header = new HeaderValueHolder();