Autoconfiguation excluded but embedded servlet container is still being used - spring

I've followed all the steps mentioned in the documentation to enable the traditional war deployment for spring boot app i.e excluded the EmbeddedServletContainerAutoConfiguration from the #EnableAutoConfiguration and I only have one such instance. Also extended SpringBootServletInitializer and make sure the packaged war doesnt have any tomcat starter dependency. Also ran the spring boot report and confirmed the EmbeddedServletContainerAutoConfiguration is in the exclusion list.
Apart from all the changes when I deploy the war it is still creating a embedded application context with embedded servlet contatiner.
What did I miss and what other areas can I inspect ? Spring boot version 1.5.13.

>
Hi Veeram,
We do not need to exclude the AutoConfiguration-classes, but excluding the tomcat dependency is needed.
You need to do is omit tomcat starter dependency from pom.xml. It gets pulled from spring-boot-starter-web as a transitive dependency. So, you need to add exclusion for it:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
Now, as you are using <packaging>war</packaging> and using SpringBootServletInitializer, we would need servlet-api dependency on the classpath.
So, add the servlet dependency to your pom.xml
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
Hope this helps!

Related

Determine compatible Versions of Spring Modules and other libraries

Which is the best way to determine the versions for my Spring modules and other libraries in a Spring Boot project?
Versions for Spring Modules
Versions for Third Party libraries
There are a lot of question when you search for "Compatible versions in Spring".
But all these questions are regarding specific libraries.
I would like to have general rules of how to determine compatible versions for my project.
You may checkout my post on this A comprehensive list of dependencies managed by latest Spring-Boot 2.3.2.RELEASE (as a custom parent)
That's is just a reference for how it should be, but you may discard the version in as they will be managed indirectly by spring itself.
Ok so, this is something almost every spring developer stumble upon. Let me try to explain this how was I able to resolve all the managed and third party libraries.
Let's suppose you want to build spring-boot microservices with a centralized configuration server.
So we can take it as following modules:
A company project starter: acts as a parent, managing the dependency
A config-server
A config-client
and let's suppose you chose spring-boot 2.3.2 version, which I used and find more stable. You would expect all the managed ones are using this spring-boot 2.3.2 version directly or indirectly.
I would highly recommend using https://mvnrepository.com
artifact: my_company-boot-starter-parent
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.2.RELEASE</version>
</parent>
<groupId>com.my_company</groupId>
<artifactId>my_company-boot-starter-parent</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>my_company starter-parent</name>
<dependencyManagement>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!-- ... -->
<!-- ... -->
<!-- other dependencies -->
<!-- ... -->
<!-- ... -->
</dependencyManagement>
If you got to Spring Boot Starter Parent ยป 2.3.2.RELEASE, under Managed Dependencies you can see the comprehensive list of all the dependencies with default version that would be referenced implicitly with boot version 2.3.2, see column Version.
The Updates column indicate that these managed dependencies are having their newest updates as this, but you are not required to override the dependency version of managed ones. If you intent to use more recent version, you have to chose more recent version of spring-boot-starter-parent. So let the spring download all the managed one itself.
With spring-boot-starter-parent 2.3.2 , they do not mention which spring-cloud-dependencies verion you should use, and this is where we get stuck and we need to figure it out.
Let us got to spring-cloud-dependencies . Hee you can see numerous version but which one to chose, it's like verifying which latest version uses spring-boot 2.3.2 indirectly.
You need to follow the managed dependency and go along with it until you find your parent version.
For example If you go for :
Hoxton.SR6
Spring Cloud Dependencies(Hoxton.SR6) -> Spring Cloud Config Dependencies( 2.2.3.RELEASE) -> Spring Cloud Starter Config(2.2.3.RELEASE) -> Spring Cloud Starter(2.2.3.RELEASE) -> Spring Boot Starter(2.3.0.RELEASE)
Here you can see, we end up using Spring Boot Starter(2.3.0.RELEASE) which is not what we expected it to be.
Hoxton.SR7
Spring Cloud Dependencies(Hoxton.SR7) -> Spring Cloud Config Dependencies(2.2.4.RELEASE) -> Spring Cloud Starter Config(2.2.4.RELEASE) -> Spring Cloud Starter(2.2.4.RELEASE) -> Spring Boot Starter(2.3.2.RELEASE)
Here we end up using same boot version 2.3.2. So in your parent pom.xml, you can set the spring cloud version as :
<properties>
<java.version>15</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<lombok.version>1.18.20</lombok.version>
<spring-cloud.version>Hoxton.SR7</spring-cloud.version>
</properties>
And in child poms (jars), you can just use the dependencies justby mentioning the group and artifact, skipping the version.
sample:
<parent>
<groupId>com.my_company</groupId>
<artifactId>my_company-boot-starter-parent</artifactId>
<version>1.0-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
<dependency>
<groupId>com.google.googlejavaformat</groupId>
<artifactId>google-java-format</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
</dependency>
</dependencies>
See, we have not provided the any version here, so spring-cloud-config-server version would be auto managed and it would be 2.2.4.RELEASE which again uses spring-boot-starter-web and spring-boot-starter both of 2.3.2 version.
Third party libraries
This is somewhat based on language version. You might want to use the latest third-party libs which is most recent till your language version supports it.
Like lombok: 1.18.20
Hope this might have helped you and others and provides an approach towards version compatibility.
Tips: Never forget to check the Managed Dependency Coordinates in Aappendix of all the spring boot release page as they keep their managed dependencies & version there. Like this one Appendix F: Dependency versions
1. Use Spring Initializr
Select all Spring modules you need in spring initializr and generate your code: https://start.spring.io/
You do not need to use the full generated code. But you should copy the library versions out of the generated pom.xml.
2. Watch out for dependency pom.xml
If available, import dependency pom.xml in your dependencyManagement.
Use the versions provided by these dependency poms.
E.g.
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Spring Dependency Version Documentation
You can also check the Spring Dependency Version Documentation. But I prefer the initilizr, because it's easier to handle.

change default web server on spring-boot 2.4.4

I'm working with Spring Boot 2.4.4 and I would change the default web server Tomcat to undertow orJHetty but I find it very difficult using both Gradle or Maven.
An old documentation exposes how do it but I'm sure all is changed because now tomcat, undertow and jetty configuration is embedded in the core library:
https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/html/howto-embedded-web-servers.html
How do it in the 2.4.4 version?
There are no changes between the versions. This is well described right at the Spring Boot 2.4.4 Reference guide, right in 3.1. Use Another Web Server section. Basically, the change consists of two steps:
Exclude embedded Tomcat server dependency from the spring-boot-starter-web artifact:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<!-- Exclude the Tomcat dependency -->
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
Include your embedded server as a separate dependency instead:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
Just don't forget to notice the following quote from the reference guide in the very same section which might or might not be relevant to you:
The version of the Servlet API has been overridden as, unlike Tomcat 9 and Undertow 2.0, Jetty 9.4 does not support Servlet 4.0.
follow three steps to change the default web server, change configuration in pom.xml.
1.exclude the default web server.
2.Include the necessary web server.
3.Maven update.
For example,
Instead of this
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
Add this one
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
for the necessary server add the appropriate web server dependency.

How to deploy spring boot framework in tomcat

I have an application that dynamically generates several web application (war files) with the same dependencies (spring boot, kafka, etc.) .my question is how I can put all these dependencies in Tomcat to reduce the size of the war files and after in my pom.xml I write for example.
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<scope>provided</scope>
</dependency>
One idea I can think of is to add the common jars to Tomcat/lib/SharedFolder and include that under shared.loader in catalina.properties and then Add the jars as provided dependencies. I can see you have already added the provided tag.
I think that will work. I haven't tried it in a sample application but I remember helping my friend do something similar to what I described above.
Hope it helps

ERROR:The type org.apache.log4j.Logger cannot be resolved. It is indirectly referenced from required .class files

Trying to upgrade a project from using Camel v2.21.2 to using Camel v2.22.0
This entails going from Spring v4.x to v5.x and from Spring-boot v1.5.x to Spring-boot v2.0.4.RELEASE.
Project uses groovy-all 2.4.15. We are not using log4j in our project, we are using slf4j-api(1.7.25) and logback(1.2.3) in our project. Yet, running a Maven install is giving an error saying that some class is using log4j
When I added log4j(1.2.17) dependency it is working fine but we don't want to add it.
Is there something that can be excluded from the spring-boot starter? Any other solutions? Any hints on how to diagnose the problem?
I think log4j or log4j2 should be in the classpath. Spring Boot v2.0.x has log4j2 added. If log4j2 is not compatible with Camel version. Exclude the log4j2 and add log4j dependency and try . Hope it should work..!
<!-- Exclude Spring Boot's Default Logging -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Add Log4j Dependency -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j</artifactId>
</dependency>

Log4J2 in Spring Boot with embedded Tomcat

I am trying to let the embedded Tomcat in Spring Boot log to my Log4J2 configuration, but it doesn't work.
According to this answer that copes with an external Tomcat: https://stackoverflow.com/a/28639068/1845463 there seems to be the need to move some jars to $Catalina_home/libs etc. I think this is not possible with Spring Boot, isn't it?
Has someone managed to get log4j2 running and be able to configure appenders for catalina log?
Thanks in advance
EDITED: The simplest way to do is to add spring-boot-starter-log4j2.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
N.B. Make sure that the other components don't need different version of log4j. This may cause run-time errors. e.g. elasticsearch java API requires 2.6+ and spring-boot-starter-log4j2:1.3.8 provides log4j:2.4.1, if we're building an app that connects elasticsearch and uses spring boot too. Then we will end up getting NoSuchMethodError or similar errors. For resolution of those errors we should add log4j2:2.6+ in our pom.
Which Spring Boot version are you using? I believe 1.4.x.RELEASE uplifted it to log4j2.
As #M.Deinum mentioned including:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
<version>1.4.6.RELEASE</version>
</dependency>
brings in:
log4j-core, log4j-api and a few more. See https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-log4j2/1.4.6.RELEASE
It might be advisable to exclude logging starter using:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>

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