Add package-info.java to all folders containing .java files

pkginfo.go

package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
)

var template = `%s
@org.eclipse.jdt.annotation.NonNullByDefault
package %s;
`

//Recursively creates NonNullByDefault annotated java package info files.
func main() {
	comment := flag.String("comment", "", "--comment <Comment>")
	workspace := flag.String("workspace", "", "--workspace <Path to workspace>")

	flag.Parse()

	if workspace == nil || len(*workspace) == 0 {
		fmt.Println("Workspace path hasn't been specified!")
		os.Exit(1)
	} else {
		absWorkingDir, err := filepath.Abs(filepath.Dir(os.Args[0]))
		if err != nil {
			panic(err)
		}
		absWorkspaceDir := filepath.Join(absWorkingDir, *workspace)

		createPackageInfo(absWorkspaceDir, *comment)
	}
}

func createPackageInfo(workspace string, comment string) error {
	return filepath.Walk(workspace, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			panic(err)
		}

		if info.IsDir() {
			if DirContainsJavaFiles(path) {
				_, infoError := os.Stat(filepath.Join(path, "package-info.java"))
				if os.IsNotExist(infoError) {
					packagePath := strings.Replace(path, workspace, "", 1)
					packagePathDots := strings.TrimPrefix(strings.Replace(packagePath, "\\", ".", -1), ".")
					fileContent := fmt.Sprintf(template, comment, packagePathDots)

					fmt.Println(fmt.Sprintf("Adding package-info.java to '%s'", path))
					ioutil.WriteFile(filepath.Join(path, "package-info.java"), []byte(fileContent), os.ModeType)
				} else {
					fmt.Println(fmt.Sprintf("Skipping '%s', as a package-info.java already exists.", path))
					//TODO NonNullByDefaultHinzufügen
				}
			}

			return nil
		}

		return nil
	})
}

func DirContainsJavaFiles(dir string) bool {
	files, err := ioutil.ReadDir(dir)

	if err != nil {
		return false
	}

	for _, fileInfo := range files {
		if strings.HasSuffix(fileInfo.Name(), ".java") {
			return true
		}
	}

	return false
}