Allow init params to be set on ProxyStreamServlet. (#2335)

* Allow init params to be set on ProxyStreamServlet.

Fixes gh-2301

* Added unit test for #gh-2301

spring-cloud-netflix-hystrix-dashboard/src/main/java/org/springframework/cloud/netflix/hystrix/dashboard/HystrixDashboardConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2015 the original author or authors.
+ * Copyright 2013-2017 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.
@@ -52,6 +52,7 @@ import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
 /**
  * @author Dave Syer
  * @author Roy Clarkson
+ * @author Fahim Farook
  */
 @Configuration
 @EnableConfigurationProperties(HystrixDashboardProperties.class)
@@ -87,10 +88,13 @@ public class HystrixDashboardConfiguration {
 
 	@Bean
 	public ServletRegistrationBean proxyStreamServlet() {
-		ProxyStreamServlet proxyStreamServlet = new ProxyStreamServlet();
-		proxyStreamServlet.setEnableIgnoreConnectionCloseHeader(dashboardProperties
-				.isEnableIgnoreConnectionCloseHeader());
-		return new ServletRegistrationBean(proxyStreamServlet, "/proxy.stream");
+		final ProxyStreamServlet proxyStreamServlet = new ProxyStreamServlet();
+		proxyStreamServlet.setEnableIgnoreConnectionCloseHeader(
+				this.dashboardProperties.isEnableIgnoreConnectionCloseHeader());
+		final ServletRegistrationBean registration = new ServletRegistrationBean(
+				proxyStreamServlet, "/proxy.stream");
+		registration.setInitParameters(this.dashboardProperties.getInitParameters());
+		return registration;
 	}
 
 	@Bean

spring-cloud-netflix-hystrix-dashboard/src/main/java/org/springframework/cloud/netflix/hystrix/dashboard/HystrixDashboardProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2015 the original author or authors.
+ * Copyright 2013-2017 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.
@@ -15,10 +15,14 @@
  */
 package org.springframework.cloud.netflix.hystrix.dashboard;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
  * @author Roy Clarkson
+ * @author Fahim Farook
  */
 @ConfigurationProperties("hystrix.dashboard")
 public class HystrixDashboardProperties {
@@ -28,6 +32,13 @@ public class HystrixDashboardProperties {
 	 * the Hystrix response stream
 	 */
 	private boolean enableIgnoreConnectionCloseHeader = false;
+	
+	/**
+	 * Initialization parameters for {@link ProxyStreamServlet}. ProxyStreamServlet itself
+	 * is not dependent on any initialization parameters, but could be used for adding web
+	 * container specific configurations. i.e. wl-dispatch-policy for WebLogic.
+	 */
+	private Map<String, String> initParameters = new HashMap<>();
 
 	public boolean isEnableIgnoreConnectionCloseHeader() {
 		return enableIgnoreConnectionCloseHeader;
@@ -38,4 +49,7 @@ public class HystrixDashboardProperties {
 		this.enableIgnoreConnectionCloseHeader = enableIgnoreConnectionCloseHeader;
 	}
 
+	public Map<String, String> getInitParameters() {
+		return this.initParameters;
+	}
 }

spring-cloud-netflix-hystrix-dashboard/src/test/java/org/springframework/cloud/netflix/hystrix/dashboard/HystrixDashboardConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2015 the original author or authors.
+ * Copyright 2013-2017 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.
@@ -16,22 +16,39 @@
 
 package org.springframework.cloud.netflix.hystrix.dashboard;
 
-import org.apache.http.Header;
-import org.apache.http.message.BasicHeader;
-import org.junit.Test;
-
-import org.springframework.mock.web.MockHttpServletResponse;
-import org.springframework.test.util.ReflectionTestUtils;
-
 import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
 
+import java.util.Map;
+
+import org.apache.http.Header;
+import org.apache.http.message.BasicHeader;
+import org.junit.After;
+import org.junit.Test;
+import org.springframework.boot.Banner.Mode;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.test.util.ReflectionTestUtils;
+
 /**
  * @author Roy Clarkson
+ * @author Fahim Farook
  */
 public class HystrixDashboardConfigurationTests {
 
+	private ConfigurableApplicationContext context;
+
+	@After
+	public void close() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+	
 	@Test
 	public void normal() {
 		MockHttpServletResponse response = new MockHttpServletResponse();
@@ -87,5 +104,17 @@ public class HystrixDashboardConfigurationTests {
 		assertThat(response.getHeader("Content-Type"), is("text/proxy.stream"));
 		assertThat(response.getHeader("Connection"), is("close"));
 	}
-
+	
+	@Test
+	public void initParameters() {
+		this.context = new SpringApplicationBuilder(HystrixDashboardConfiguration.class)
+							.properties("hystrix.dashboard.init-parameters.wl-dispatch-polixy=work-manager-hystrix")
+							.web(false).bannerMode(Mode.OFF).run();
+		final ServletRegistrationBean registration = this.context.getBean(ServletRegistrationBean.class);
+		assertNotNull(registration);
+		
+		final Map<String, String> initParameters = registration.getInitParameters();
+		assertNotNull(initParameters);
+		assertThat(initParameters.get("wl-dispatch-polixy"), is("work-manager-hystrix"));
+	}
 }