[FIXED] VSCode and Java Setup: No compatible Jar

Issue

I'm setting up Java within VSCode and just can't seem to get the JREs correct. Can someone please lend a pair of eyes and point out what I'm missing?

2 errors I'm seeing:

1. Build path specifies execution environment JavaSE-1.8. There are no JREs installed in the workspace that are strictly compatible with this environment.
   
2. The compiler compliance specified is 1.8 but a JRE 11 is used

OS: Windows 10
Java version installed: JDK 11 (version 11.0.2)

Environment Variables:
JAVA_HOME > C:\Program Files\Java\jdk-11.0.12
MAVEN_HOME > C:\Program Files\apache-maven-3.8.2
PATH > %MAVEN_HOME%\bin

POM:

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>sqa.tan</groupId>
  <artifactId>automation</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>automation</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <maven.compiler.source>1.8</maven.compiler.source>
   <maven.compiler.target>1.8</maven.compiler.target>
</properties>

<dependencies>

  <dependency>
    <groupId>io.appium</groupId>
    <artifactId>java-client</artifactId>
    <version>7.5.1</version>
  </dependency>

  <dependency>
    <groupId>com.google.apis</groupId>
    <artifactId>google-api-services-gmail</artifactId>
    <version>v1-rev20200919-1.31.0</version>
  </dependency>

  <dependency>
    <groupId>com.google.apis</groupId>
    <artifactId>google-api-services-oauth2</artifactId>
    <version>v2-rev20200213-1.31.0</version>
  </dependency>

  <dependency>
    <groupId>com.google.oauth-client</groupId>
    <artifactId>google-oauth-client-jetty</artifactId>
    <version>1.31.5</version>
  </dependency>

  <dependency>
    <groupId>io.github.bonigarcia</groupId>
    <artifactId>webdrivermanager</artifactId>
    <version>4.4.3</version>
  </dependency>

  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-1.2-api</artifactId>
    <version>2.7</version>
  </dependency>

  <dependency>
    <groupId>org.awaitility</groupId>
    <artifactId>awaitility</artifactId>
    <version>4.1.0</version>
  </dependency>

  <dependency>
    <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>selenium-java</artifactId>
    <version>3.141.59</version>
  </dependency>

  <dependency>
    <groupId>org.testng</groupId>
    <artifactId>testng</artifactId>
    <version>7.4.0</version>
    <scope>test</scope>
  </dependency>
</dependencies>

<build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
          <configuration>
             <source>1.8</source>
             <target>1.8</target>
          </configuration>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
</build>
</project>

Screenshot of a few jars in the JRE System Library

Solution

You have specified JAVA 1.8 in your POM file but you have Java 11 installed on your system.

Make the below changes to the POM file:

Replace:

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <maven.compiler.source>1.8</maven.compiler.source>
   <maven.compiler.target>1.8</maven.compiler.target>
</properties>

To,

<properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target> 
</properties>

Also, replace

  <configuration>
     <source>1.8</source>
     <target>1.8</target>
  </configuration>

To,

  <configuration>
     <source>11</source>
     <target>11</target>
  </configuration>

Answered By - Alok