Changed startup handler setter to onStartup

Author: sapessi

README.md

@@ -146,7 +146,7 @@ public String echoServletHeaders(@Context HttpServletRequest context) {
 You can register [`Filter`](https://docs.oracle.com/javaee/7/api/javax/servlet/Filter.html) implementations by implementing a `StartupsHandler` as defined in the `AwsLambdaServletContainerHandler` class. The `onStartup` methods receives a reference to the current `ServletContext`.
 
 ```java
-handler.setStartupHandler(c -> {
+handler.onStartup(c -> {
     FilterRegistration.Dynamic registration = c.addFilter("CustomHeaderFilter", CustomHeaderFilter.class);
     // update the registration to map to a path
     registration.addMappingForUrlPatterns(EnumSet.of(DispatcherType.REQUEST), true, "/*");

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsLambdaServletContainerHandler.java

@@ -42,7 +42,6 @@ public abstract class AwsLambdaServletContainerHandler<RequestType, ResponseType
     // Variables - Private
     //-------------------------------------------------------------
 
-
     private FilterChainManager filterChainManager;
 
     //-------------------------------------------------------------
@@ -92,23 +91,23 @@ protected void setServletContext(final ServletContext context) {
 
 
     /**
-     * You can use the <code>setStartupHandler</code> to intercept the ServletContext as the Spring application is
+     * You can use the <code>onStartup</code> to intercept the ServletContext as the Spring application is
      * initialized and inject custom values. The StartupHandler is called after the <code>onStartup</code> method
      * of the <code>LambdaSpringApplicationinitializer</code> implementation. For example, you can use this method to
      * add custom filters to the servlet context:
      *
      * <pre>
      * {@code
      *      handler = SpringLambdaContainerHandler.getAwsProxyHandler(EchoSpringAppConfig.class);
-     *      handler.setStartupHandler(c -> {
+     *      handler.onStartup(c -> {
      *      // the "c" parameter to this function is the initialized servlet context
      *      c.addFilter("CustomHeaderFilter", CustomHeaderFilter.class);
      *      });
      * }
      * </pre>
      * @param h A lambda expression that implements the <code>StartupHandler</code> functional interface
      */
-    public void setStartupHandler(final StartupHandler h) {
+    public void onStartup(final StartupHandler h) {
         startupHandler = h;
     }
 

aws-serverless-java-container-spring/src/test/java/com/amazonaws/serverless/proxy/spring/SpringServletContextTest.java

@@ -32,7 +32,7 @@ public static void setUp() {
         try {
             handler = SpringLambdaContainerHandler.getAwsProxyHandler(EchoSpringAppConfig.class);
             handler.setRefreshContext(true);
-            handler.setStartupHandler(c -> {
+            handler.onStartup(c -> {
                 FilterRegistration.Dynamic registration = c.addFilter("CustomHeaderFilter", CustomHeaderFilter.class);
                 // update the registration to map to a path
                 registration.addMappingForUrlPatterns(EnumSet.of(DispatcherType.REQUEST), true, "/*");