使用Java构造文件路径

Question

I am trying to create a file, but file path is constructed through String Concats that uses some internal variables and labels, I am getting following error :

Exception in thread "main" java.io.IOException: The filename, directory name, or volume label syntax is incorrect
    at java.io.WinNTFileSystem.createFileExclusively(Native Method)
    at java.io.File.createNewFile(Unknown Source)
    at CopyEJ.CopyEJ.main(CopyEJ.java:133)

Is there a standard approach to built such files ?

String s_path = text_dir + "\\" + time_stmp + "_" + "Session" + "_" + file_name;


        File ssw = new File(s_path);

        ssw.createNewFile();  //Errors Out here

Answer 1

This will help you:

String path = "D://abc" + filename+ ".txt";
System.out.println("Path--- " + path);
File file = new File(path);
file.createNewFile()

Answer 2

You need to create the folder ( directory ) first:

String s_path = text_dir + "/" + time_stmp + "_" + "Session" + "_" + file_name;
File ssw = new File(s_path);

ssw.getParentFile().mkdirs();
ssw.createNewFile();

Answer 3

If You are using Java 1.7 you can rewrite it as follows:

Path s_path = Paths.get(text_dir, time_stmp + "_" + "Session" + "_" + file_name);
Files.createDirectories(s_path.getParent());  
File ssw = s_path.toFile();
ssw.createNewFile();

Paths.get() will use default system path separator.