Replace Streams with Loops

First version of replacing streams

fix wwwAuthenticate and codestyle

fix errors in implementation to pass tests

Fix review notes

Remove uneccessary final to align with cb

Short circuit way to authorize

Simplify error message, make code readably

Return error while duplicate key found

Delete check for duplicate, checkstyle issues

Return duplicate error

Fixes gh-7154

web/src/main/java/org/springframework/security/web/header/writers/ClearSiteDataHeaderWriter.java

@@ -16,9 +16,6 @@
 
 package org.springframework.security.web.header.writers;
 
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -69,7 +66,7 @@ public final class ClearSiteDataHeaderWriter implements HeaderWriter {
 	public ClearSiteDataHeaderWriter(String ...sources) {
 		Assert.notEmpty(sources, "sources cannot be empty or null");
 		this.requestMatcher = new SecureRequestMatcher();
-		this.headerValue = Stream.of(sources).map(this::quote).collect(Collectors.joining(", "));
+		this.headerValue = joinQuotes(sources);
 	}
 
 	@Override
@@ -84,6 +81,15 @@ public final class ClearSiteDataHeaderWriter implements HeaderWriter {
 		}
 	}
 
+	private String joinQuotes(String ...sources) {
+		StringBuilder sb = new StringBuilder();
+		for (int i = 0; i < sources.length-1; i++) {
+			sb.append(quote(sources[i])).append(", ");
+		}
+		sb.append(quote(sources[sources.length-1]));
+		return sb.toString();
+	}
+
 	private static final class SecureRequestMatcher implements RequestMatcher {
 		public boolean matches(HttpServletRequest request) {
 			return request.isSecure();

web/src/main/java/org/springframework/security/web/server/authentication/DelegatingServerAuthenticationSuccessHandler.java

@@ -23,8 +23,7 @@ import reactor.core.publisher.Mono;
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
+import java.util.ArrayList;
 
 /**
  * Delegates to a collection of {@link ServerAuthenticationSuccessHandler} implementations.
@@ -43,7 +42,10 @@ public class DelegatingServerAuthenticationSuccessHandler implements ServerAuthe
 	@Override
 	public Mono<Void> onAuthenticationSuccess(WebFilterExchange exchange,
 			Authentication authentication) {
-		Stream<Mono<Void>> results = this.delegates.stream().map(delegate -> delegate.onAuthenticationSuccess(exchange, authentication));
-		return Mono.when(results.collect(Collectors.toList()));
+		List<Mono<Void>> results = new ArrayList<>();
+		for (ServerAuthenticationSuccessHandler delegate : delegates) {
+			results.add(delegate.onAuthenticationSuccess(exchange, authentication));
+		}
+		return Mono.when(results);
 	}
 }

web/src/main/java/org/springframework/security/web/server/authentication/logout/DelegatingServerLogoutHandler.java

@@ -20,8 +20,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
-import java.util.Objects;
-import java.util.stream.Collectors;
 
 import reactor.core.publisher.Mono;
 
@@ -50,10 +48,12 @@ public class DelegatingServerLogoutHandler implements ServerLogoutHandler {
 
 	@Override
 	public Mono<Void> logout(WebFilterExchange exchange, Authentication authentication) {
-		return Mono.when(this.delegates.stream()
-				.filter(Objects::nonNull)
-				.map(delegate -> delegate.logout(exchange, authentication))
-				.collect(Collectors.toList())
-		);
+		List<Mono<Void>> results = new ArrayList<>();
+		for (ServerLogoutHandler delegate : delegates) {
+			if (delegate != null) {
+				results.add(delegate.logout(exchange, authentication));
+			}
+		}
+		return Mono.when(results);
 	}
 }

web/src/main/java/org/springframework/security/web/server/header/ClearSiteDataServerHttpHeadersWriter.java

@@ -20,9 +20,6 @@ import org.springframework.web.server.ServerWebExchange;
 
 import reactor.core.publisher.Mono;
 
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
 /**
  * <p>Writes the {@code Clear-Site-Data} response header when the request is secure.</p>
  *
@@ -81,9 +78,12 @@ public final class ClearSiteDataServerHttpHeadersWriter implements ServerHttpHea
 	}
 
 	private String transformToHeaderValue(Directive... directives) {
-		return Stream.of(directives)
-				.map(Directive::getHeaderValue)
-				.collect(Collectors.joining(", "));
+		StringBuilder sb = new StringBuilder();
+		for (int i = 0; i < directives.length - 1; i++) {
+			sb.append(directives[i].headerValue).append(", ");
+		}
+		sb.append(directives[directives.length - 1].headerValue);
+		return sb.toString();
 	}
 
 	private boolean isSecure(ServerWebExchange exchange) {

web/src/main/java/org/springframework/security/web/server/header/CompositeServerHttpHeadersWriter.java

@@ -17,8 +17,7 @@ package  org.springframework.security.web.server.header;
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
+import java.util.ArrayList;
 
 import org.springframework.web.server.ServerWebExchange;
 
@@ -43,8 +42,10 @@ public class CompositeServerHttpHeadersWriter implements ServerHttpHeadersWriter
 
 	@Override
 	public Mono<Void> writeHttpHeaders(ServerWebExchange exchange) {
-		Stream<Mono<Void>> results = writers.stream().map( writer -> writer.writeHttpHeaders(exchange));
-		return Mono.when(results.collect(Collectors.toList()));
+		List<Mono<Void>> results = new ArrayList<>();
+		for (ServerHttpHeadersWriter writer : writers) {
+			results.add(writer.writeHttpHeaders(exchange));
+		}
+		return Mono.when(results);
 	}
-
 }