Not able to create JAR file for gradle project

Question

I want to create a jar file which I can upload on AWS, but every time I run the command gradle jar from command prompt I get the following error.

> Task :compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or -- 
debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

I get 'Build Successful' whenever I run gradle clean in command prompt. Here is the content of build.gradle:

buildscript {
ext {
    springBootVersion = '2.0.4.RELEASE'
}
repositories {
    mavenCentral()
    maven {
        url "https://plugins.gradle.org/m2/"
    }
}
dependencies {
    classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
    classpath "net.ltgt.gradle:gradle-apt-plugin:0.18"
}
}



apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'
apply plugin: 'net.ltgt.apt'

group = 'com.myproject.api'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = JavaVersion.VERSION_1_8


ext {
  lombokVersion = '1.16.20'
  mapstructVersion = '1.2.0.Final'
}

repositories {
    mavenCentral()
    mavenLocal()
    jcenter()
             flatDir {
                dirs 'libs'
        }
    

}

dependencies {

    compile('org.springframework.boot:spring-boot-starter-web')
    compile('org.springframework.boot:spring-boot-starter-data-jpa')
    compile('org.springframework.boot:spring-boot-starter-mail')
    compile('org.springframework.boot:spring-boot-starter-thymeleaf')
    compile('org.springframework.data:spring-data-jpa')
    compile('io.springfox:springfox-swagger2:2.9.2')
    compile('io.springfox:springfox-swagger-ui:2.9.2')
    compile group: 'commons-io', name: 'commons-io', version: '2.6'
 
    
    compile group: 'org.json', name: 'json', version: '20180813'
    compile files('libs/checksum_2.0.0.jar')

    compileOnly("org.projectlombok:lombok:${lombokVersion}")
    compileOnly("org.mapstruct:mapstruct-jdk8:${mapstructVersion}")
    compileOnly("org.mapstruct:mapstruct-processor:${mapstructVersion}")

    runtime('org.springframework.boot:spring-boot-devtools')
    runtime('mysql:mysql-connector-java')
    testCompile('org.springframework.boot:spring-boot-starter-test')
}


eclipse {
    classpath {
        file.whenMerged { cp ->
            cp.entries.add( new org.gradle.plugins.ide.eclipse.model.SourceFolder('build/generated/source/apt/ma 
   in', null) )
        }
    }
}

Do I need to add any plugins? Thanks in advance. Please help

Danaides

> Compilation failed; see the compiler error output for details. try to locate the source of the compilation error and fix it – Anaphase

@Anaphase I saw the source of the error it says: "Resolving global dependency management for project 'myproject-' Excluding [org.apache.tomcat:tomcat-annotations-api, ognl:ognl] Excluding [] Caching disabled for task ':compileJava' because: Build cache is disabled Task ':compileJava' is not up-to-date because: Task has failed previously. All input files are considered out-of-date for incremental task ':compileJava'. Full recompilation is required because no incremental change information is available. This is usually caused by clean builds or changing compiler arguments" – Danaides

The problem is not with gradle. The problem is with your Java code. It doesn't compile. Read the compilation errors you get from the compiler and fix them. That's what Compilation failed; see the compiler error output for details. means. – Ancylostomiasis

@JBNizet I am new to programming. Could you please help me find compiler error output window in spring tool suite. – Danaides

Answer 1

I was using gradle clean and gradle build instead of gradlew clean and gradlew build.
gradle commands worked for me.

Danaides

Answer 2

Open task manger and force stop Java(TM) Platform SE binary and delete

C:\Users\{current user}\.gradle\caches\jars-9\jars-9.lock file

Chiropractic

Many thanks, this solution worked for me after hours of try & error – Weft