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I wanted to run some of the class files present inside build/install/ folder. So, I have created task like below.

Note : dummy java class present inside build/install/dummy.class

task runWithExec(type: JavaExec) {
    workingDir = "$buildDir/install/"
    //classpath = files("$buildDir/install/lib")
    main = 'dummy'    
}

but, when i execute this task, I am getting exception saying, ‘Error: Could not find or load main class dummy’

why i am getting such a exception when i am setting my workingDir properly.