java assemble filter for java source, java resources

java-filter.gradle

apply plugin: JavaFilterPlugin

class JavaFilterPlugin implements Plugin<Project> {
    void apply(Project project) {
        project.afterEvaluate {
            if (project.file('filter.properties').exists()) {
                def processResources = project.tasks.findByName("processResources")
                processResources.configure {
                    from(processResources.source) {
                        filesMatching('*') {
                            Properties properties = new Properties()
                            properties.load(new FileInputStream(project.file('filter.properties')))
                            filter(ReplaceTokens, tokens: properties, beginToken: '${', endToken: '}')
                        }
                    }
                }
                def compileJava = project.tasks.findByName("compileJava")
                def filterJavaSources = project.tasks.create("filterJavaSources", Copy) {
                    from(compileJava.source) {
                        filesMatching('**/*.java') {
                            Properties properties = new Properties()
                            properties.load(new FileInputStream(project.file('filter.properties')))
                            filter(ReplaceTokens, tokens: properties, beginToken: '${', endToken: '}')
                        }
                    }
                    into "$project.buildDir/generated-java-src"
                }

                compileJava.configure {
                    dependsOn filterJavaSources
                    setSource(filterJavaSources.outputs.files)
                }
            }
        }
    }
}