inputfile.java

源码为科学出版社出版的英文<java设计模式>(影印版)所用的所有例子程序

import java.awt.*;
import java.io.*;

public class InputFile
{
RandomAccessFile f = null;
boolean errflag;
String s = null;
 public InputFile(String fname) 
 {
 errflag = false;
  try
    {
    //open file
    f = new RandomAccessFile(fname, "r");
    }
   catch (IOException e)
    {
    //print error if not found
     System.out.println("no file found");
     errflag = true;    //and set flag
    }
  }
//-----------------------------------------
public boolean checkErr()
 {
 return errflag;
 }
//-----------------------------------------
public String read()
{
//read a single field up to a comma or end of line
String ret = "";
if (s == null)          //if no data in string
   {
   s = readLine();      //read next line
   }
if (s != null)          //if there is data
 {
 s.trim();              //trim off blanks
 int i = s.indexOf(",");  //find next comma
 if (i <= 0)
  {
  ret = s.trim();       //if no commas go to end of line
  s = null;             //and null out stored string
  }
 else
  {
  ret = s.substring(0, i).trim(); //return left of comma      
  s = s.substring(i+1); //save right of comma
  }
}
else
  ret = null;
return ret;             //return string
}
//-----------------------------------------
public String readLine()
 {
 //read in a line from the file
 s = null;
 try
  {
  s = f.readLine();     //could throw error
  }
 catch (IOException e)
 {
 errflag = true;
 System.out.println("File read error");
 }
 return s;
 }
//-----------------------------------------
public void close()
{
try
 {
 f.close();     //close file
 }
catch (IOException e)
 {System.out.println("File close error");
  errflag = true;
 }
}
//-----------------------------------------
}