Header predicate option in AbstractRequestLoggingFilter

Closes gh-22244

Author: rstoyanchev

spring-web/src/main/java/org/springframework/web/filter/AbstractRequestLoggingFilter.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.
@@ -18,12 +18,15 @@
 
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
+import java.util.Enumeration;
+import java.util.function.Predicate;
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;
 
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -95,6 +98,9 @@ public abstract class AbstractRequestLoggingFilter extends OncePerRequestFilter
 
 	private boolean includePayload = false;
 
+	@Nullable
+	private Predicate<String> headerPredicate;
+
 	private int maxPayloadLength = DEFAULT_MAX_PAYLOAD_LENGTH;
 
 	private String beforeMessagePrefix = DEFAULT_BEFORE_MESSAGE_PREFIX;
@@ -176,6 +182,26 @@ protected boolean isIncludePayload() {
 		return this.includePayload;
 	}
 
+	/**
+	 * Configure a predicate for selecting which headers should be logged if
+	 * {@link #setIncludeHeaders(boolean)} is set to {@code true}.
+	 * <p>By default this is not set in which case all headers are logged.
+	 * @param headerPredicate the predicate to use
+	 * @since 5.2
+	 */
+	public void setHeaderPredicate(@Nullable Predicate<String> headerPredicate) {
+		this.headerPredicate = headerPredicate;
+	}
+
+	/**
+	 * The configured {@link #setHeaderPredicate(Predicate) headerPredicate}.
+	 * @since 5.2
+	 */
+	@Nullable
+	public Predicate<String> getHeaderPredicate() {
+		return this.headerPredicate;
+	}
+
 	/**
 	 * Set the maximum length of the payload body to be included in the log message.
 	 * Default is 50 characters.
@@ -320,7 +346,17 @@ protected String createMessage(HttpServletRequest request, String prefix, String
 		}
 
 		if (isIncludeHeaders()) {
-			msg.append(";headers=").append(new ServletServerHttpRequest(request).getHeaders());
+			HttpHeaders headers = new ServletServerHttpRequest(request).getHeaders();
+			if (getHeaderPredicate() != null) {
+				Enumeration<String> names = request.getHeaderNames();
+				while (names.hasMoreElements()) {
+					String header = names.nextElement();
+					if (!getHeaderPredicate().test(header)) {
+						headers.set(header, "masked");
+					}
+				}
+			}
+			msg.append(";headers=").append(headers);
 		}
 
 		if (isIncludePayload()) {

spring-web/src/test/java/org/springframework/web/filter/RequestLoggingFilterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -17,6 +17,7 @@
 package org.springframework.web.filter;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
@@ -100,24 +101,41 @@ public void noQueryStringAvailable() throws Exception {
 		assertTrue(filter.afterRequestMessage.contains("[uri=/hotels]"));
 	}
 
+	@Test
+	public void headers() throws Exception {
+		final MockHttpServletRequest request = new MockHttpServletRequest("POST", "/hotels");
+		request.setContentType("application/json");
+		request.addHeader("token", "123");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		FilterChain filterChain = new NoOpFilterChain();
+		filter.setIncludeHeaders(true);
+		filter.setHeaderPredicate(name -> !name.equalsIgnoreCase("token"));
+		filter.doFilter(request, response, filterChain);
+
+		assertNotNull(filter.beforeRequestMessage);
+		assertEquals("Before request [uri=/hotels;headers=[Content-Type:\"application/json\", token:\"masked\"]]",
+				filter.beforeRequestMessage);
+
+		assertNotNull(filter.afterRequestMessage);
+		assertEquals("After request [uri=/hotels;headers=[Content-Type:\"application/json\", token:\"masked\"]]",
+				filter.afterRequestMessage);
+	}
+
 	@Test
 	public void payloadInputStream() throws Exception {
 		filter.setIncludePayload(true);
 
 		final MockHttpServletRequest request = new MockHttpServletRequest("POST", "/hotels");
 		MockHttpServletResponse response = new MockHttpServletResponse();
 
-		final byte[] requestBody = "Hello World".getBytes("UTF-8");
+		final byte[] requestBody = "Hello World".getBytes(StandardCharsets.UTF_8);
 		request.setContent(requestBody);
 
-		FilterChain filterChain = new FilterChain() {
-			@Override
-			public void doFilter(ServletRequest filterRequest, ServletResponse filterResponse)
-					throws IOException, ServletException {
-				((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
-				byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
-				assertArrayEquals(requestBody, buf);
-			}
+		FilterChain filterChain = (filterRequest, filterResponse) -> {
+			((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
+			byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
+			assertArrayEquals(requestBody, buf);
 		};
 
 		filter.doFilter(request, response, filterChain);
@@ -134,16 +152,12 @@ public void payloadReader() throws Exception {
 		MockHttpServletResponse response = new MockHttpServletResponse();
 
 		final String requestBody = "Hello World";
-		request.setContent(requestBody.getBytes("UTF-8"));
-
-		FilterChain filterChain = new FilterChain() {
-			@Override
-			public void doFilter(ServletRequest filterRequest, ServletResponse filterResponse)
-					throws IOException, ServletException {
-				((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
-				String buf = FileCopyUtils.copyToString(filterRequest.getReader());
-				assertEquals(requestBody, buf);
-			}
+		request.setContent(requestBody.getBytes(StandardCharsets.UTF_8));
+
+		FilterChain filterChain = (filterRequest, filterResponse) -> {
+			((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
+			String buf = FileCopyUtils.copyToString(filterRequest.getReader());
+			assertEquals(requestBody, buf);
 		};
 
 		filter.doFilter(request, response, filterChain);
@@ -160,20 +174,16 @@ public void payloadMaxLength() throws Exception {
 		final MockHttpServletRequest request = new MockHttpServletRequest("POST", "/hotels");
 		MockHttpServletResponse response = new MockHttpServletResponse();
 
-		final byte[] requestBody = "Hello World".getBytes("UTF-8");
+		final byte[] requestBody = "Hello World".getBytes(StandardCharsets.UTF_8);
 		request.setContent(requestBody);
 
-		FilterChain filterChain = new FilterChain() {
-			@Override
-			public void doFilter(ServletRequest filterRequest, ServletResponse filterResponse)
-					throws IOException, ServletException {
-				((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
-				byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
-				assertArrayEquals(requestBody, buf);
-				ContentCachingRequestWrapper wrapper =
-						WebUtils.getNativeRequest(filterRequest, ContentCachingRequestWrapper.class);
-				assertArrayEquals("Hel".getBytes("UTF-8"), wrapper.getContentAsByteArray());
-			}
+		FilterChain filterChain = (filterRequest, filterResponse) -> {
+			((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
+			byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
+			assertArrayEquals(requestBody, buf);
+			ContentCachingRequestWrapper wrapper =
+					WebUtils.getNativeRequest(filterRequest, ContentCachingRequestWrapper.class);
+			assertArrayEquals("Hel".getBytes(StandardCharsets.UTF_8), wrapper.getContentAsByteArray());
 		};
 
 		filter.doFilter(request, response, filterChain);