>gradle clean
:clean

BUILD SUCCESSFUL

Total time: 3.93 secs

>gradle test
:compileJava
:processResources UP-TO-DATE
:classes
:compileTestJava
:processTestResources UP-TO-DATE
:testClasses
:test

mayton.EncodingTest > test FAILED
    org.junit.ComparisonFailure at EncodingTest.java:12

1 test completed, 1 failed
:test FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':test'.
> There were failing tests. See the report at: file://........./TestGradle3/build/reports/tests/index.html

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

BUILD FAILED

Total time: 6.222 secs

package mayton;

import org.junit.Ignore;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class EncodingTest{

 @Test
 public void test(){
    assertEquals("АБВ from Gradle","АБВ from Gradle");
 } 

}

apply plugin: 'java'
apply plugin: 'application'

mainClassName = "mayton.Hello"
compileJava.options.encoding = 'UTF-8'

version = '1.0'

repositories {
    mavenCentral()
}

dependencies {
    compile     'log4j:log4j:1.2.17'
    testCompile 'junit:junit:4.7',
                'log4j:log4j:1.2.17'
}

>gradle jar
:compileJava
:processResources UP-TO-DATE
:classes
:jar

BUILD SUCCESSFUL

Total time: 5.981 secs

>cd build
build>

build>cd libs
build\libs>java -jar TestGradle3-1.0.jar

no main manifest attribute, in TestGradle3-1.0.jar

D:\sql.ru\TestGradle3\build\libs>unzip TestGradle3-1.0.jar
Archive:  TestGradle3-1.0.jar
   creating: META-INF/
  inflating: META-INF/MANIFEST.MF
   creating: mayton/
  inflating: mayton/Hello.class

D:\sql.ru\TestGradle3\build\libs>cd META-INF
D:\sql.ru\TestGradle3\build\libs\META-INF>

D:\sql.ru\TestGradle3\build\libs\META-INF>cat MANIFEST.MF
Manifest-Version: 1.0

apply plugin: 'java'
apply plugin: 'application'

mainClassName = "mayton.Hello"
compileJava.options.encoding = 'UTF-8'

version = '1.0'

repositories {
    mavenCentral()
}

dependencies {
    compile     'log4j:log4j:1.2.17'
    testCompile 'junit:junit:4.7',
                'log4j:log4j:1.2.17'
}

tasks.withType(Compile) {
  options.encoding = 'UTF-8'
}

D:\sql.ru\TestGradle3>gradle clean
:clean

BUILD SUCCESSFUL

Total time: 3.804 secs

D:\sql.ru\TestGradle3>gradle test
:compileJava
:processResources UP-TO-DATE
:classes
:compileTestJava
:processTestResources UP-TO-DATE
:testClasses
:test

BUILD SUCCESSFUL

Total time: 6.505 secs