Inplace html files that swap out version numbers but still allow gradle to keep up to date checks

build.gradle

apply plugin: 'java'
apply plugin: 'jetty'

sourceCompatibility = 1.8
version = '1.0'

repositories {
    mavenCentral()
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.11'
}

war {
    expand([version: version])
    duplicatesStrategy DuplicatesStrategy.FAIL
}

task warList(dependsOn: war) << {
    def tree= zipTree(war.archivePath);
    tree.each { println it; if (it.name == 'index.html') { println it.toPath().readLines().toString() } }
}

to be specific about which files are expanded you can use

with {
    from('index.html')
    expand([version: version])
}