driver.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

import java.io.*;
import java.util.Scanner;

/** Program to write to a new binary file and read from it using Scanner  (end of Section 13.6)
 *  Author: David Riley
 *  Date: January, 2005
 */
public class Driver  {

    public Driver()   {
		try {
			FileOutputStream outStream;
            PrintWriter printWriter;
			
			outStream = new FileOutputStream( "example.txt" );
			printWriter = new PrintWriter( outStream );
			printWriter.print( 12+" " );
        	printWriter.print( true+" " );
			printWriter.println( 98.7+" " );
			printWriter.println( "hello world" );
			printWriter.println('Z');
			printWriter.flush();
			printWriter.close();
		}
		catch (IOException e)  {
			System.out.println("ERROR writing." );
    }

            
	try {
        FileInputStream inStream;
        Scanner inScan;
        inStream = new FileInputStream( "example.txt" );
        inScan = new Scanner( inStream );
            
        while ( inScan.hasNext() )   {
            if (inScan.hasNextBoolean()) 
                System.out.println( "Boolean value: " + inScan.nextBoolean());
            else if (inScan.hasNextLong()) 
                System.out.println( "Integer value: " + inScan.nextLong());
            else if (inScan.hasNextDouble()) 
                System.out.println( "Double value: " + inScan.nextDouble());
            else // it must be a String
                System.out.println( "String value: " + inScan.next());
            }
            inScan.close();
        }
        catch (IOException e)  {
            System.out.println("ERROR reading." );
        }
    }
}