《Java语言程序设计与数据结构》编程练习答案（第十七章）

英文名：Introduction to Java Programming and Data Structures, Comprehensive Version, 11th Edition

17.1

import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           File dst = new File("Exercise17_01.txt");        FileWriter fw = new FileWriter(dst,true);        try(                PrintWriter output = new PrintWriter(fw);){
               for(int i=0;i<100;i++) {
                   output.print((int) (Math.random() * 100)+" ");            }            output.print('\n');        }    }}

17.2

import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           try(FileOutputStream musashi = new FileOutputStream("Exercise17_02.dat",true);)        {
               for(int i=0;i<100;i++)                musashi.write((int)(Math.random()*100));        }    }}

17.3

import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           try(                FileInputStream yamato = new FileInputStream("Exercise17_02.dat");                ){
               int v=0;            while(yamato.read()!=-1)                v++;            System.out.print(v);        }    }}

17.4

import java.util.*;import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           File yukikaze = new File(args[0]);        Scanner input = new Scanner(yukikaze);        String nagato="";        while(input.hasNext())            nagato+=input.nextLine();        input.close();        try(DataOutputStream shimakaze = new DataOutputStream(new FileOutputStream(args[1]));){
               shimakaze.writeChars(nagato);        }    }}

17.5

import java.util.*;import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           int[] PoW = {
   1,2,3,4,5};        Date KGV = new Date();        double DoY = 5.5;        try(                ObjectOutputStream Bismark = new ObjectOutputStream(new FileOutputStream("Exercise17_05.dat"));                ){
               Bismark.writeObject(PoW);            Bismark.writeObject(KGV);            Bismark.writeDouble(DoY);        }        try(                ObjectInputStream Tilpitz = new ObjectInputStream(new FileInputStream("Exercise17_05.dat"));                ){
               int[] ss= (int[])(Tilpitz.readObject());            Date jj=(Date)(Tilpitz.readObject());            double bb= Tilpitz.readDouble();            for(int i=0;i

17.8

public class book {
       public static void main(String[] args)            throws Exception    {
           RandomAccessFile eagle = new RandomAccessFile("Exercise17_08.dat","rw");        eagle.writeInt(1);        eagle.close();        RandomAccessFile victory = new RandomAccessFile("Exercise17_08.dat","rw");        int swordfish = victory.readInt();        swordfish++;        victory.setLength(0);        victory.writeInt(swordfish);    }}

17.10

import java.util.*;import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           System.out.print("Enter the src: ");        Scanner input = new Scanner(System.in);        String jj = input.next();        System.out.print("Enter the num: ");        int num = input.nextInt();        RandomAccessFile src = new RandomAccessFile(jj,"r");        src.seek(0);        long llen = src.length()/num;        for(int i=1;i<=num;i++){
               RandomAccessFile tmp = new RandomAccessFile(jj+"."+i,"rw");            for(long j=0;j

17.14

import java.util.*;import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           System.out.print("Enter the src and dst: ");        Scanner input = new Scanner(System.in);        String jj = input.next();        String mm = input.next();        RandomAccessFile src = new RandomAccessFile(jj,"r");        RandomAccessFile dst = new RandomAccessFile(mm,"rw");        src.seek(0);        for(int i=0;i

17.15

import java.util.*;import java.io.*;public class book {
       public static void main(String[] args)            throws Exception    {
           System.out.print("Enter the src and dst: ");        Scanner input = new Scanner(System.in);        String jj = input.next();        String mm = input.next();        RandomAccessFile src = new RandomAccessFile(jj,"r");        RandomAccessFile dst = new RandomAccessFile(mm,"rw");        src.seek(0);        for(int i=0;i