[FIXED] How to fix Heroku deployment error in SprinBoot

Issue

Hi i have an Springboot application and i want to deploy it but when try to deploy from heroku CLI i get this error and i am new into this i don't know how to fix this. I have to solve this problem until tomorrow but i don't know what should i do . This is what i get in cmd when i try to deploy my project to heroku

[INFO] BUILD FAILURE
       [INFO] ------------------------------------------------------------------------
       [INFO] Total time:  9.571 s
       [INFO] Finished at: 2022-05-04T15:53:46Z
       [INFO] ------------------------------------------------------------------------
       [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project todoapp: Fatal error compiling: invalid target release: 11 -> [Help 1]
       [ERROR] 
       [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
       [ERROR] Re-run Maven using the -X switch to enable full debug logging.
       [ERROR] 
       [ERROR] For more information about the errors and possible solutions, please read the following articles:
       [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
 !     ERROR: Failed to build app with Maven
       We're sorry this build is failing! If you can't find the issue in application code,
       please submit a ticket so we can help: https://help.heroku.com/
 !     Push rejected, failed to compile Java app.
 !     Push failed

And this is my xml file i am not sure where the error comes from but i think it comes from XML file:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.7</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>todoapp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>todoapp</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>jakarta.validation</groupId>
            <artifactId>jakarta.validation-api</artifactId>
            <version>2.0.2</version>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.6</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-boot-starter</artifactId>
            <version>3.0.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.21.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.9.0</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Solution

SOLVED.

I added System.properties file:

java.runtime.version=11

Answered By - Murathan Business
Answer Checked By - Marie Seifert (JavaFixing Admin)