java input/ output file problems -

the aim here method create file if not exist if exists : open , modify it... errors createnewfile() not member of class, exist() not member of class..i imported java.io.* post snippet..i hightlight problems comments quicker help...

  public void writecoordtofile () throws ioexception   {        file file = new file("fermipresentcoord.txt");      //  boolean yes = createnewfile("fermipresentcoord.txt") throws ioexception; error when try        //boolean yes = exists("fermipresentcoord.txt"); error exists not member of file         // creates file        file.createnewfile();         // creates filewriter object        filewriter writer = new filewriter(file);         // writes content file        writer.write(pos_let);        writer.write(pos_num);        writer.flush();        writer.close();    } 

you need give file object, createnewfile() method of file class. function's of class can accessed using file's object(file).methodname()

file file = new file("fermipresentcoord.txt"); boolean yes = file.createnewfile()  boolean yes1 = file.exists();