Fix HAL browser entry point with contextPath

Previously, if the `contextPath` of the application wasn't the root, the
HAL browser could not initialize since the `entryPoint` was referring to
an invalid location.

This commit makes sure to take the `contextPath` into account.

Closes gh-5814

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/mvc/HalBrowserMvcEndpoint.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -38,6 +38,7 @@ import org.springframework.web.servlet.resource.TransformedResource;
  * @author Dave Syer
  * @author Phillip Webb
  * @author Andy Wilkinson
+ * @author Stephane Nicoll
  * @since 1.3.0
  */
 public class HalBrowserMvcEndpoint extends HalJsonMvcEndpoint
@@ -142,15 +143,15 @@ public class HalBrowserMvcEndpoint extends HalJsonMvcEndpoint
 			resource = transformerChain.transform(request, resource);
 			if (resource.getFilename().equalsIgnoreCase(
 					HalBrowserMvcEndpoint.this.location.getHtmlFile())) {
-				return replaceInitialLink(resource);
+				return replaceInitialLink(request.getContextPath(), resource);
 			}
 			return resource;
 		}
 
-		private Resource replaceInitialLink(Resource resource) throws IOException {
+		private Resource replaceInitialLink(String contextPath, Resource resource) throws IOException {
 			byte[] bytes = FileCopyUtils.copyToByteArray(resource.getInputStream());
 			String content = new String(bytes, DEFAULT_CHARSET);
-			String initial = getManagementServletContext().getContextPath() + getPath();
+			String initial = contextPath + getManagementServletContext().getContextPath() + getPath();
 			content = content.replace("entryPoint: '/'", "entryPoint: '" + initial + "'");
 			return new TransformedResource(resource, content.getBytes(DEFAULT_CHARSET));
 		}

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/mvc/HalBrowserMvcEndpointManagementContextPathIntegrationTests.java

@@ -36,8 +36,10 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.context.WebApplicationContext;
 
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.forwardedUrl;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@@ -88,6 +90,13 @@ public class HalBrowserMvcEndpointManagementContextPathIntegrationTests {
 				.andExpect(forwardedUrl("/admin/browser.html"));
 	}
 
+	@Test
+	public void actuatorBrowserHtml() throws Exception {
+		this.mockMvc.perform(get("/admin/browser.html").accept(MediaType.APPLICATION_JSON))
+				.andExpect(status().isOk())
+				.andExpect(content().string(containsString("entryPoint: '/admin'")));
+	}
+
 	@Test
 	public void trace() throws Exception {
 		this.mockMvc.perform(get("/admin/trace").accept(MediaType.APPLICATION_JSON))

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/mvc/HalBrowserMvcEndpointServerContextPathIntegrationTests.java

@@ -85,6 +85,18 @@ public class HalBrowserMvcEndpointServerContextPathIntegrationTests {
 				entity.getBody().contains("<title"));
 	}
 
+	@Test
+	public void actuatorBrowserEntryPoint() throws Exception {
+		HttpHeaders headers = new HttpHeaders();
+		headers.setAccept(Arrays.asList(MediaType.TEXT_HTML));
+		ResponseEntity<String> entity = new TestRestTemplate().exchange(
+				"http://localhost:" + this.port + "/spring/actuator/browser.html", HttpMethod.GET,
+				new HttpEntity<Void>(null, headers), String.class);
+		assertEquals(HttpStatus.OK, entity.getStatusCode());
+		assertTrue("Wrong body: " + entity.getBody(),
+				entity.getBody().contains("entryPoint: '/spring/actuator'"));
+	}
+
 	@Test
 	public void actuatorLinks() throws Exception {
 		HttpHeaders headers = new HttpHeaders();