setfilelength.java

本书属于《开发专家之 Sun ONE》系列丛书

//【代码7-3-6】
//SetFileLength.java
import java.io.*;
class SetFileLength.java
{
    public static void main(String[] args)
{
        if (args.length != 2)
{
            System.err.println(
                "usage: java Main <new filename> <size in bytes>");
            System.exit(-1);
        }
        long size = 0;
        try
{
            size = Long.parseLong(args[1]);
        }
catch (NumberFormatException e)
{
            System.err.println(
                "usage: java Main <new filename> <size in bytes>");
            System.exit(-1);
        }

        try
{
            RandomAccessFile raf = new RandomAccessFile(args[0], "rw");
            raf.setLength(size);     // extend file to be specified size
            raf.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}