oneliner

LineShrink.groovy

//
// usage:
//   groovy LineShrink.groovy <target.java>
//   java -jar ~/.m2/repository/org/codehaus/groovy/groovy/2.5.8/groovy-2.5.8.jar LineShrink.groovy <target.java>
//
def input = new File(args[0])

def methodDefinitionStartPattern = /^\s{4}(public|protected|private)?\s{1,2}[a-zA-Z]{1}[^\s\(\)]+\s*[a-zA-Z]{1}[^\s\(\)]+\(.*$/
def methodDefinitionEndPattern = /^\s{4}\}$/
def inMethodDefinition = false
def lineCommentPattern = /^\s*\/\/.*$/
def stack = []

input.eachLine { line ->

    if (line.trim().empty) {
        return
    }

    if (inMethodDefinition) {

        if (line ==~ lineCommentPattern) {
            return
        }

        stack << line
        def m = line =~ methodDefinitionEndPattern
        if (m) {
            println(stack.join(""))
            stack = []
            inMethodDefinition = false
        }
        return
    }

    def m = line =~ methodDefinitionStartPattern
    if (m) {
        inMethodDefinition = true
        stack << line
        return
    }

    println(line)
}