Honor Host header for server name/port in MckHtSrvRq

Prior to this commit, the getServerName() and getServerPort() methods
in MockHttpServletRequest simply returned the 'mocked' serverName and
serverPort but ignored the 'Host' header entirely. Per the Servlet
specification, however, these methods must parse the server name or
port from the 'Host' header if it is present and otherwise fall back to
the resolved server name or port.

This commit fixes this by ensuring that getServerName() and
getServerPort() properly parse the server's name or port from the
'Host' header if it is present in the request. If the 'Host' header is
not present, MockHttpServletRequest falls back to returning the
'mocked' serverName and serverPort.

Issue: SPR-12088

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

@@ -107,6 +107,8 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	private static final String CONTENT_TYPE_HEADER = "Content-Type";
 
+	private static final String HOST_HEADER = "Host";
+
 	private static final String CHARSET_PREFIX = "charset=";
 
 	private static final ServletInputStream EMPTY_SERVLET_INPUT_STREAM =
@@ -544,6 +546,19 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public String getServerName() {
+		String host = getHeader(HOST_HEADER);
+		if (host != null) {
+			host = host.trim();
+			if (host.startsWith("[")) {
+				host = host.substring(1, host.indexOf(']'));
+			}
+			else if (host.contains(":")) {
+				host = host.substring(0, host.indexOf(':'));
+			}
+			return host;
+		}
+
+		// else
 		return this.serverName;
 	}
 
@@ -553,6 +568,22 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public int getServerPort() {
+		String host = getHeader(HOST_HEADER);
+		if (host != null) {
+			host = host.trim();
+			int idx;
+			if (host.startsWith("[")) {
+				idx = host.indexOf(':', host.indexOf(']'));
+			}
+			else {
+				idx = host.indexOf(':');
+			}
+			if (idx != -1) {
+				return Integer.parseInt(host.substring(idx + 1));
+			}
+		}
+
+		// else
 		return this.serverPort;
 	}
 

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

@@ -42,6 +42,8 @@ import static org.junit.Assert.*;
  */
 public class MockHttpServletRequestTests {
 
+	private static final String HOST = "Host";
+
 	private MockHttpServletRequest request = new MockHttpServletRequest();
 
 
@@ -212,6 +214,86 @@ public class MockHttpServletRequestTests {
 		assertEqualEnumerations(Collections.enumeration(preferredLocales), request.getLocales());
 	}
 
+	@Test
+	public void getServerNameWithDefaultName() {
+		assertEquals("localhost", request.getServerName());
+	}
+
+	@Test
+	public void getServerNameWithCustomName() {
+		request.setServerName("example.com");
+		assertEquals("example.com", request.getServerName());
+	}
+
+	@Test
+	public void getServerNameViaHostHeaderWithoutPort() {
+		String testServer = "test.server";
+		request.addHeader(HOST, testServer);
+		assertEquals(testServer, request.getServerName());
+	}
+
+	@Test
+	public void getServerNameViaHostHeaderWithPort() {
+		String testServer = "test.server";
+		request.addHeader(HOST, testServer + ":8080");
+		assertEquals(testServer, request.getServerName());
+	}
+
+	@Test
+	public void getServerNameViaHostHeaderAsIpv6AddressWithoutPort() {
+		String ipv6Address = "[2001:db8:0:1]";
+		request.addHeader(HOST, ipv6Address);
+		assertEquals("2001:db8:0:1", request.getServerName());
+	}
+
+	@Test
+	public void getServerNameViaHostHeaderAsIpv6AddressWithPort() {
+		String ipv6Address = "[2001:db8:0:1]:8081";
+		request.addHeader(HOST, ipv6Address);
+		assertEquals("2001:db8:0:1", request.getServerName());
+	}
+
+	@Test
+	public void getServerPortWithDefaultPort() {
+		assertEquals(80, request.getServerPort());
+	}
+
+	@Test
+	public void getServerPortWithCustomPort() {
+		request.setServerPort(8080);
+		assertEquals(8080, request.getServerPort());
+	}
+
+	@Test
+	public void getServerPortViaHostHeaderAsIpv6AddressWithoutPort() {
+		String testServer = "[2001:db8:0:1]";
+		request.addHeader(HOST, testServer);
+		assertEquals(80, request.getServerPort());
+	}
+
+	@Test
+	public void getServerPortViaHostHeaderAsIpv6AddressWithPort() {
+		String testServer = "[2001:db8:0:1]";
+		int testPort = 9999;
+		request.addHeader(HOST, testServer + ":" + testPort);
+		assertEquals(testPort, request.getServerPort());
+	}
+
+	@Test
+	public void getServerPortViaHostHeaderWithoutPort() {
+		String testServer = "test.server";
+		request.addHeader(HOST, testServer);
+		assertEquals(80, request.getServerPort());
+	}
+
+	@Test
+	public void getServerPortViaHostHeaderWithPort() {
+		String testServer = "test.server";
+		int testPort = 9999;
+		request.addHeader(HOST, testServer + ":" + testPort);
+		assertEquals(testPort, request.getServerPort());
+	}
+
 	@Test
 	public void getRequestURL() {
 		request.setServerPort(8080);