Add Tomcat ProtocolHandlerCustomizer

[philwebb]

Hi, this is a first-timers-only issue. This means we've worked to make it more legible to folks who either haven't contributed to our codebase before, or even folks who haven't contributed to open source before.

If that's you, we're interested in helping you take the first step and can answer questions and help you out as you do. Note that we're especially interested in contributions from people from groups underrepresented in free and open source software!

If you have contributed before, consider leaving this one for someone new, and looking through our general ideal-for-contribution issues. Thanks!

Background

Spring Boot provides a number of callback interfaces that can be used to customize the web server. A TomcatConnectorCustomizer can be used to customize a Tomcat Connector.

Problem

Customizing the ProtocolHandler on the Connector requires creating a TomcatConnectorCustomizer. This is bit tedious as can be seen from the example below:

@Bean
public TomcatConnectorCustomizer connectorCustomizer() {
       return (connector) -> { ((AbstractHttp11Protocol<?>) connector
				.getProtocolHandler()).setProcessorCache(250));
       };
}

Instead, if we added a TomcatProtocolHandlerCustomizer and applied those beans automatically, that would simplify the configuration to the following:

@Bean
public TomcatProtocolHandlerCustomizer<AbstractHttp11Protocol<?>> processorCacheCustomizer() {
	return (handler) -> handler.setProcessorCache(250);
}

Solution

Add a TomcatProtocolHandlerCustomizer type. Beans of TomcatProtocolHandlerCustomizer type should be applied automatically to TomcatServletWebServerFactory and TomcatReactiveWebServerFactory. For TomcatServletWebServerFactory, this can be done here and the configuration for the reactive one can be found here.

The ObjectProvider interface can be used for injecting a dependency. Here is an example that can be used to inject customizers when there can be 0..n of them.

Tests for the servlet and reactive versions are here and here respectively.

Steps to Fix

• Claim this issue with a comment below and ask any clarifying questions you need
• Set up a repository locally following the Contributing Guidelines
• Try to fix the issue following the steps above
• Commit your changes and start a pull request.

[pas2al]

I would love to give it a try.

[atulkulkarni18]

I would like to fix this issue.

[mbhave]

@pas2al It's all yours! Please let us know if you have any questions.

@atulkulkarni18 Thanks, we'll reach out to you if @pas2al isn't able to work on it for some reason.

[mhewedy]

I like the idea 😃

[FDelporte]

@philwebb @mbhave great idea! You can add me to the waiting list :-)

[saket88]

@philwebb @mbhave I am on the waitlist :)

[sundarraj4u]

Can you put me on the waiting list for future issue fix.

[snicoll]

@sundarraj4u sorry but that's not how this works. We don't have a waiting list, please watch for future issues flagged with first-timers-only.

[pas2al]

I have problems setting up the project. I did import the project using the root pom.xml in IntelliJ and selected the modules i want to work on:

• spring-boot/spring-boot-project/spring-boot
• spring-boot/spring-boot-project/spring-boot-autoconfigure

Before, i built the whole project from the root with mvn clean install. Some test were failing due to dependency problems. This is the error when running a build for the whole project:

[INFO] [ERROR] Failed to execute goal on project spring-boot-sample-oauth2-resource-server: Could not resolve dependencies for project org.springframework.boot:spring-boot-sample-oauth2-resource-server:jar:2.2.0.BUILD-SNAPSHOT: Failed to collect dependencies at com.squareup.okhttp3:mockwebserver:jar:3.9.0 -> com.squareup.okhttp3:okhttp:jar:3.9.0: Failed to read artifact descriptor for com.squareup.okhttp3:okhttp:jar:3.9.0: Could not transfer artifact com.squareup.okhttp3:okhttp:pom:3.9.0 from/to central (https://repo.maven.apache.org/maven2): Connection reset -> [Help 1]

This is the rest of the log, every other module was successfully:

[INFO] Spring Boot Samples Invoker ........................ FAILURE [08:43 min]
[INFO] Spring Boot Tests .................................. SKIPPED
[INFO] Spring Boot Integration Tests ...................... SKIPPED
[INFO] Spring Boot Configuration Processor Tests .......... SKIPPED
[INFO] Spring Boot DevTools Tests ......................... SKIPPED
[INFO] Spring Boot Hibernate 5.2 tests .................... SKIPPED
[INFO] Spring Boot Server Tests ........................... SKIPPED
[INFO] Spring Boot Launch Script Integration Tests 2.2.0.BUILD-SNAPSHOT SKIPPED

The spring-boot module works fine in my IDE, but spring-boot-autoconfigure does not compile, due to dependency problems. It does not find Spring dependencies or even JUnit. I rebuilt thespring-boot-autoconfigure and reimported the maven module in IntelliJ. It still does not compile. The spring-boot-autoconfigure module does build when i run a mvn clean install. Can you help me?