passing a input file as a parameter

Question

I really need help on my java project. My problem is that I am new to Java and I can't figure out how to pass a input file in java.

I need to open a .dat file, read the file, and set it as a named constant so I can pass it to other methods as a string.

For example I want to open myFle.dat in my beginning method and pass it to a method like this so I can work with it their

doMethod(fileString);

If possible talk simple java to me because I am new to this.

Answer 1

You need to open a Stream to the File and read that into a StringBuilder , here is a simple example:

final File file = new File("/path/to/my/file.txt");
final StringBuilder stringBuilder = new StringBuilder();
try (final Reader reader = new InputStreamReader(new FileInputStream(file), "UTF-8")) {
    final CharBuffer cb = CharBuffer.allocate(1024);
    while (reader.read(cb) != -1) {
        stringBuilder.append(cb.flip());
        cb.clear();
    }
}
final String fileAsString = stringBuilder.toString();

This assumes the file is in "UTF-8" encoding. The code uses the Java 7 try-with-resources construct to close the Reader when you're done with it. Otherwise you would need to use a try-finally.