输出给定字符串在哪些文件中出现

public class ReadStringAndPrintPath 
{
    public static void main(String[] args) 
    {
        System.out.println("Hello World!");
        String str = "test";
        File file = new File("a");
        File[] list = file.listFiles();
        searchString(list,str);
    }
    public static void searchString(File[] files,String str){
        for(int i = 0 ; i < files.length; i ++){
            if(files[i].isFile()){
                //是文件，搜索是否存在字符串
                try{
                    Scanner scan = new Scanner(files[i]);
                    while(scan.hasNext()){
                        if(scan.nextLine().indexOf(str) != -1){
                            System.out.println(files[i].getAbsolutePath());
                            break;
                        }
                    }
                }catch(IOException ex){
                    ex.printStackTrace();
                }
            }else{
                //是文件夹
                File[] list = files[i].listFiles();
                searchString(list,str);
            }
        }
    }
}