Gradle - Could not target platform: 'Java SE 8' using tool chain: 'JDK 7 (1.7)'

Question

This is what worked for me (Intellij Idea 2018.1.2):

1) Navigate to: File -> Settings -> Build, Execution, Deployment -> Build Tools -> Gradle

2) Gradle JVM: change to version 1.8

3) Re-run the gradle task

For IntelliJ 2019:

Intellij IDEA -> Preferences -> Build, Execution, Deployment -> Build Tools -> Gradle -> Gradle JVM

Select correct version.

For IntelliJ 2019, JDK 13 and gRPC:

Intellij IDEA -> Preferences -> Build, Execution, Deployment -> Build Tools -> Gradle -> Gradle JVM

and Select correct version.

you might also have to adding below line in your build.gradle dependencies

compileOnly group: 'javax.annotation', name: 'javax.annotation-api', version: '1.3.2'

Finally I imported my Gradle project. These are the steps:

1. I switched from local Gradle distrib to Intellij Idea Gradle Wrapper (gradle-2.14).
2. I pointed system variable JAVA_HOME to JDK 8 (it was 7th previously) as I had figured out by experiments that Gradle Wrapper could process the project with JDK 8 only.
3. I deleted previously manually created file gradle.properties (with org.gradle.java.homevariable) in windows user .gradle directory as, I guessed, it didn't bring any additional value to Gradle.

Since I had to compile some source with 7 compatibility, because of some legacy system and ran into the same problem. I found out that in the gradle configuration there where two options set to java 8

sourceCompatibility = 1.8
targetCompatibility = 1.8

switching these to 1.7 solved the problem for me, keeping JAVA_HOME pointing to the installed JDK-7

sourceCompatibility = 1.7
targetCompatibility = 1.7

I had a very related issue but for higher Java versions:

$ ./gradlew clean assemble

... <other normal Gradle output>

Could not target platform: 'Java SE 11' using tool chain: 'JDK 8 (1.8)'.

I noticed that the task succeeded when running using InteliJ. Adding a file (same level as build.gradle) called .java-version solved my issue:

 # .java-version
 11.0.3

you have to change the -> sourceCompatibility = '1.7' in build.Gradle