maven spring library correct dependency - spring

Let's say I am creating a new project, maven based, and I want to use spring 4.2.3.RELEASE.
I also want to use spring-test and spring security and X, Y and Z.
How can I know for sure what exact versions to add in maven to avoid conflicts?
Thanks
later edit:
can this help me?
Maven "Bill Of Materials" Dependency
It is possible to accidentally mix different versions of Spring JARs when using Maven. For example, you may find that a third-party library, or another Spring project, pulls in a transitive dependency to an older release. If you forget to explicitly declare a direct dependency yourself, all sorts of unexpected issues can arise.
To overcome such problems Maven supports the concept of a "bill of materials" (BOM) dependency. You can import the spring-framework-bom in your dependencyManagement section to ensure that all spring dependencies (both direct and transitive) are at the same version.
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-framework-bom</artifactId>
<version>4.2.3.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
An added benefit of using the BOM is that you no longer need to specify the <version> attribute when depending on Spring Framework artifacts:
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</dependency>
<dependencies>

You are right, the BOM is one of the most powerfull ways to fight (even maven based) dependency hell.

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.

Using dependencies of an artifact

I have a complex Spring project with tens of dependencies and modules. I notice that some of them might be replaced by spring-boot-starters.
However, when I'm replacing some dependencies with starters in main, parent pom, I'm getting errors in children modules.
Here's an example:
PARENT POM
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-activemq</artifactId>
<version>2.0.5.RELEASE</version>
</dependency>
</dependencies>
</dependencyManagement>
MODULE POM
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jms</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
According to maven repository spring-boot-starter-activemq depends on, among others, spring-boot-starter and spring-jms.
Should these dependencies be available for modules?
Is there a way to use dependencies like that? I would make pom files shorter.
Or maybe is it a bad idea to do it like that and I should define all dependencies I will use in dependencyManagement?
In a POM, you should have all the dependencies that you directly use in your code. Do not rely on transitive resolution for things you actively use.
Your construction does not work because you did not manage the spring-jsm and spring-boot-starter in your dependencyManagement. Being a dependency of the managed dependency does not help.

How to say to Maven which dependency to use

Right now I'm migrating legacy project from Spring 1 to bigger version (yeah I know it's 2017). The project has 1 dependency which contains a lot of spring/ibatis dependencies. One of ibatis dependency is version 2.1.6 but migrating spring requires bigger version(2.3.4) I put the new dependency in my pom but maven keeps using the old one. I know that it's not soo good to have 2 different version in the project and the main goal for me is to remove the old big dependency but right now I want to start the project with the new one without removing the old one.
How to tell maven which dependency to use and how to ignore the other one? If this is not possible tell me how to migrate easily.
Thank you.
add the <exclusions> tag under the <dependency> section of the pom.
More Details here
Sample:
<project>
...
<dependencies>
<dependency>
<groupId>sample.ProjectA</groupId>
<artifactId>Project-A</artifactId>
<version>1.0</version>
<scope>compile</scope>
<exclusions>
<exclusion> <!-- declare the exclusion here -->
<groupId>sample.ProjectB</groupId>
<artifactId>Project-B</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</project>

How do I indicate to maven that one dependency provides another?

After version 11.0.2, Google's guava library switched to Java 6. Fortunately, for those of us stuck on Java 5, they also released a "guava-jdk5" artifact.
Unfortunately, some of my dependencies pull in guava 11.0.2 transitively. Which leaves my project containing both guava-jdk5 and guava.
Normally when I have conflicting versions, I can use the "dependencymanagement" tag to indicate which version to pull in. But since these are two different artifacts, I do not understand how to do this. Ultimately I want to tell maven, guava and guava-jdk5 are the same artifact and I want the 17.0 version of guava-jdk5 to be the one that is used. How do I do this?
Thanks!
One easy way is to use a dependency exclusion, nutshell from the link:
<project>
...
<dependencies>
<dependency>
<groupId>sample.ProjectA</groupId>
<artifactId>Project-A</artifactId>
<version>1.0</version>
<scope>compile</scope>
<exclusions>
<exclusion> <!-- declare the exclusion here -->
<groupId>sample.ProjectB</groupId>
<artifactId>Project-B</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</project>

spring.io hibernate config

I'm using the Spring IO 1.0.1 BOM to manage my dependencies for my project. I've imported it in my super-pom's dependency management section like this -
<dependencyManagement>
<dependencies>
<dependency>
<groupId>io.spring.platform</groupId>
<artifactId>platform-bom</artifactId>
<version>1.0.1.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
...
Now, in a submodule POM of my project, I've declared these dependencies
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
</dependency>
And my final packaged war includes both hibernate-jpa-2.0 and hibernate-jpa-2.1. Since the entity manager depends on 2.1 and the api is 2.0. These are causing conflicts within my deployed app.
I cannot find a declaration of 2.1 in the platform bom so I'm confused about how to proceed. The documentation lists both of these as libraries provided by the platform, but the BOM doesn't provide any resolution between their conflicting versions. What is the recommended approach? Should I manually exclude 2.0 and explicitly declare 2.1 even if its not in the parent BOM? Should I force hibernate-entitymanager to use the 2.0 APIs?
I was hoping that the IO platform BOM would help me with these kinds of collisions.

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