Heroku deploy build failure for Spring Boot REST API

Question

I have a Spring Boot REST API locally.

It is successfully generating the.war file locally when I run mvn clean package.

Now I want to deploy it to Heroku.

These are the steps I've done.

1. Uploded the code to a github respository. Let's say \myrestapi.

2. Opened a terminal to run Heroku CLI commands

3. Logged in heroku

   heroku login

4. Ran command to create the app on heroku

   heroku create myrestapi

   This command didn't work. Got the message saying the name "myrestapi" already existed.

   So I changed the name to something else. Let's say "cl-myrestapi":

   heroku create cl-myrestapi

   It ran successfully.

5. Ran command to create the free postgreSQL database on heroku:

   heroku addons:create heroku-postgresql:hobby-dev

6. Git push

   git push heroku main

   This starts downloads successfully.

   But then generates the following error:

    remote:        [INFO] BUILD FAILURE
    remote:        [INFO] ------------------------------------------------------------------------
    remote:        [INFO] Total time:  14.653 s
    remote:        [INFO] Finished at: 2021-02-19T18:43:12Z
    remote:        [INFO] ------------------------------------------------------------------------
    remote:        [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-
    compile) on project myrestapi: Fatal error compiling: invalid target release: 11 -> [Help 1]
    remote:        [ERROR]
    remote:        [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
    remote:        [ERROR] Re-run Maven using the -X switch to enable full debug logging.
    remote:        [ERROR]
    remote:        [ERROR] For more information about the errors and possible solutions, please read the following artic
    les:
    remote:        [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
    remote:
    remote:  !     ERROR: Failed to build app with Maven
    remote:        We're sorry this build is failing! If you can't find the issue in application code,
    remote:        please submit a ticket so we can help: https://help.heroku.com/
    remote:
    remote:  !     Push rejected, failed to compile Java app.
    remote:
    remote:  !     Push failed
    remote:  !
    remote:  ! ## Warning - The same version of this code has already been built: e11a85238783f54ee30765ba4f8a55354930be
    09
    remote:  !
    remote:  ! We have detected that you have triggered a build from source code with version e11a85238783f54ee30765ba4f
    8a55354930be09
    remote:  ! at least twice. One common cause of this behavior is attempting to deploy code from a different branch.
    remote:  !
    remote:  ! If you are developing on a branch and deploying via git you must run:
    remote:  !
    remote:  !     git push heroku <branchname>:main
    remote:  !
    remote:  ! This article goes into details on the behavior:
    remote:  !   https://devcenter.heroku.com/articles/duplicate-build-version
    remote:
    remote: Verifying deploy...
    remote:
    remote: !       Push rejected to cl-myrestapi.
    remote:
    To https://git.heroku.com/cl-myrestapi.git
     ! [remote rejected] main -> main (pre-receive hook declined)
    error: failed to push some refs to 'https://git.heroku.com/cl-myrestapi.git'

Why am I getting this error since it is building successfully locally?

There are only two differences I can see:

1. The need to have a different project name on heroku (see step 4 above)

2. Application.properties is different.

This is my original application.properties (that runs locally).

spring.datasource.url=jdbc:postgresql://localhost:5432/myrestapi
spring.datasource.username=xxx
spring.datasource.password=yyy
spring.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.hibernate.ddl-auto=update

This is the updated application.properties (being uploaded to heroku)

spring.datasource.url=${JDBC_DATASOURCE_URL}
spring.jpa.hibernate.ddl-auto=update

UPATE: Noted that when the git push heroku main command is executed, at the begining it says "Installing jdk 1.8", while I'm using version 11.

So that seems to be the issue.

To solve that I tried to add a System.properties file at the root with the following line:

java.runtime.version=11

But didn't solve.

Answer 1

• First Don't forget to add this in pom.xml

<properties>
        <java.version>11</java.version>
    </properties>

• Second, check project SDK and project language level (in project structure) both of them should be 11.

Check Java compiler in settings and make sure that project-byte-code-version and target-byte-code-version have set 11.

• Also for last chance if Heroku can't deploy, try this at bottom of your pom.xml file.

<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>
        </plugins>
    </build>