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1、实验4：输入输出流一、实验目的1. 理解I/O流的概念，掌握其分类，掌握Java I/O基本原理。2. 掌握对硬盘上的文件和目录进行操作的基本方法。3. 掌握FileInputStream、FileOutputStream类的基本使用方法。4. 掌握FileReader类 、FileWriter类的使用。5. 掌握BufferedWriter类 、BufferedWriter类的使用。6. 掌握RandomAccessFile类的使用。7. 掌握对象序列化的方法及ObjectInputStream、ObjectOutputStream类的基本使用方法。二、实验要求本次实验要求以Eclipse为
2、开发平台。三、实验内容与步骤1编写一个Java Application程序，实现如下的设计功能：运行该程序可以列出当前目录下的所有文件。import java.io.*;public class sy1 public static void main(String args)File file= new File(D:);file.mkdir();Filef1=file.listFiles();for(int i=0;if1.length;i+)if(f1i.isDirectory()System.out.println(dirctory is+f1i.getName();elseSystem
3、.out.println(flie is+f1i.getName();2编写一个Java Application程序（文件名为CopyFile.java），要求通过字节流从该文件中读取数据并写入到“temp.txt”文件中去，实现该文件的复制。import java.io.*;public class CopyFile public static void main(String args)int a;byte b=你好吗，逗比.getBytes();tryFileOutputStream out=new FileOutputStream(D:jdk1.8.0_20新建文件夹zzjsrczzj
4、temp.txt); out.write(b);out.close();catch(IOException e)System.out.println(error+e);3编写一个程序（文件名为ReadExample.java），将程序文件本身的内容每行开头添加上行号拷贝到另一个文件tempfile.txt中。import java.io.*;public class ReadExample public static void main(String args)int a;char b=new char18;tryFile f=new File(D:jdk1.8.0_20新建文件夹zzjsrc
5、zzjReadExample.java);FileReader in=new FileReader(f);FileWriter out=new FileWriter(D:jdk1.8.0_20新建文件夹zzjsrczzjtempfile.txt);while(a=in.read(b,0,18)!=-1)String s=new String(b,0,18);out.write(b);System.out.print(b);in.close();out.close();catch(IOException e)System.out.println(error+e);4现在有如下格式的学生成绩单（文
6、本格式）score.txt：姓名:张三，数学72分，物理67分，英语70分.姓名:李四，数学92分，物理98分，英语88分.姓名:周五，数学68分，物理80分，英语77分.要求按行读入成绩单，并在该行的后面加上该运动员的总成绩，然后再将该行写入到一个名字为socreAnalysis.txt的文件中。请按如下的程序模板中的要求，将【代码】替换为Java程序代码，以完成该程序。Fenxi.java文件清单：import java.util.*;public class Fenxi public static int getTotalScore(String s) String regex=0123
7、456789 ; /匹配非数字的正则表达式 String digitMess=s.replaceAll(regex,*); StringTokenizer fenxi = new StringTokenizer(digitMess,*); int totalScore=0; while(fenxi.hasMoreTokens() int score = Integer.parseInt(fenxi.nextToken(); totalScore = totalScore+score; return totalScore; AnalysisResult.java文件清单：import java.
8、io.*;import java.util.*;public class AnalysisResult public static void main(String args) File fRead = new File(score.txt); File fWrite = new File(socreAnalysis.txt); try Writer out = 【代码1】/创建指向文件fWrite的文件输出流对象out BufferedWriter bufferWrite = 【代码2】/创建指向out的bufferWrite流 Reader in = 【代码3】/创建指向文件fRead的文
9、件输入流对象in BufferedReader bufferRead =【代码4】/创建指向in的缓冲流 String str = null; while(str=bufferRead.readLine()!=null) int totalScore=Fenxi.getTotalScore(str); str = str+总成绩:+totalScore; System.out.println(str); bufferWrite.write(str); bufferWrite.newLine(); bufferRead.close(); bufferWrite.close(); catch(IO
10、Exception e) System.out.println(e.toString(); class AnalysisResult public static void main(String args) File fRead = new File(D:jdk1.8.0_20新建文件夹zzjsrczzjscore.txt); File fWrite = new File(D:jdk1.8.0_20新建文件夹zzjsrczzjsocreAnalysis.txt); try Writer out =new FileWriter(fWrite); BufferedWriter bufferWrit
11、e =new BufferedWriter(out); Reader in =new FileReader(fRead); BufferedReader bufferRead =new BufferedReader(in); String str = null; while(str=bufferRead.readLine()!=null) int totalScore=Fenxi.getTotalScore(str); str = str+总成绩:+totalScore; System.out.println(str); bufferWrite.write(str); bufferWrite.
12、newLine(); bufferRead.close(); bufferWrite.close(); catch(IOException e) System.out.println(e.toString(); 5编写一个程序，利用缓冲流实现接收键盘输入的数据，并写入到指定文件中（如当前目录下的tt.txt文件）的功能，要求键盘输入”exit”时结束。（提示：）import java.io.*;import java.util.Scanner;public class sy5 public static void main(String args) Scanner sc=new Scanner
13、(System.in);String s = sc.next();tryFileWriter out=new FileWriter(D:jdk1.8.0_20新建文件夹zzjsrczzjtt.txt);while(s=exit)BufferedWriter br=new BufferedWriter(out);br.write(s);s=sc.next();catch(IOException e)System.out.println(error+e);6下面的程序使用随机流进行文件的保存和读取，请按如下的程序模板中的要求，将【代码】替换为Java程序代码，以完成该程序，使得程序在控制台的输出结
14、果如下：程序清单：import java.io.*;public class testRandom2 public static void main(String args) try RandomAccessFile rf = new RandomAccessFile(rtest.dat, rw);for (int i = 0; i 10; i+) rf.writeInt(i);rf.writeDouble(i * 1.414);rf.close();rf = new RandomAccessFile(rtest.dat, rw);rf.seek (【代码1】);rf.writeInt(47)
15、;rf.writeDouble(47.00021);rf.close();rf = new RandomAccessFile(rtest.dat, r);for (int i = 0; i 10; i+) ;System.out.println(Value + rf.readInt() + : +【代码2】);rf.【代码3】; catch (IOException e) System.out.println(e.toString();import java.io.*;public class testRandom2 public static void main(String args) t
16、ry RandomAccessFile rf = new RandomAccessFile(rtest.dat, rw);for (int i = 0; i 10; i+) rf.writeInt(i);rf.writeDouble(i * 1.414);rf.close();rf = new RandomAccessFile(rtest.dat, rw);rf.seek (0);rf.writeInt(47);rf.writeDouble(47.00021);rf.close();rf = new RandomAccessFile(rtest.dat, r);for (int i = 0;
17、i 10; i+) ;System.out.println(Value + rf.readInt() + : +rf.readDouble();rf.close(); catch (IOException e) System.out.println(e.toString();7. 下面的程序使用对象的序列化及对象流进行对象的保存和读取，请按如下的程序模板中的要求，将【代码】替换为Java程序代码，以完成该程序。程序清单：import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOExceptio
18、n;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;public class SerializableDemo public static void main(String args) throws Exception student stu = new student(20131064, 张三, 20, 西华大学);FileOutputStream fout = new FileOutputStream(data1.ser);ObjectOutputS
19、tream oout = new 【代码1】;/ 输出对象oout.writeObject(stu);oout.close();stu = null;FileInputStream fin = new 【代码2】;ObjectInputStream oin = new 【代码3】;/ 读入对象stu = 【代码4】;oin.close();System.out.println(学生信息：);System.out.println(ID： + stu.id);System.out.println(name： + stu.name);System.out.println(age： + stu.age
20、);System.out.println(department： + stu.department);class student implements Serializable int id;String name;int age;String department;public student(int id, String name, int age, String department) this.id = id;this.name = name;this.age = age;this.department = department;import java.io.FileInputStre
21、am;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;public class SerializableDemo private static student stu;public static void main(String args) throws Exception stu = new student(20131064, 张三,
22、20, 西华大学);FileOutputStream fout = new FileOutputStream(data1.ser);ObjectOutputStream oout = new ObjectOutputStream(fout);oout.writeObject(stu);oout.close();stu = null;FileInputStream fin = new FileInputStream(data1.ser);ObjectInputStream oin = new ObjectInputStream(fin);stu =new student(20131064, 张三
23、, 20, 西华大学);oin.close();System.out.println(学生信息：); System.out.println(ID: +stu.id);System.out.println(name： + stu.name);System.out.println(age： + stu.age);System.out.println(department： + stu.department);class student implements Serializable int id;String name;int age;String department;public studen
24、t(int id, String name, int age, String department) this.id = id;this.name = name;this.age = age;this.department = department;8. 下面的程序以字节为单位进行文件的读写操作，请阅读并分析该程序，上机运行查看效果，然后修改程序，使其以字符流方式进行文件的读写操作。程序清单：import java.io.*;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class readerbyt
25、e extends JFrame implements ActionListener JButton b1, b2, b3;JTextField jt1;JTextArea jt2;readerbyte() setTitle(FileInputStream-FileOutputStream演示);getContentPane().setLayout(new FlowLayout();this.setDefaultLookAndFeelDecorated(true);this.setSize(450, 350);b1 = new JButton(写入);b2 = new JButton(读取);
26、b3 = new JButton(退出);b1.addActionListener(this);b2.addActionListener(this);b3.addActionListener(this);jt1 = new JTextField(10);jt2 = new JTextArea(10, 30);jt2.setLineWrap(true);jt2.setWrapStyleWord(true);JScrollPane jspa = new JScrollPane(jt2);JPanel p1 = new JPanel();p1.add(new JLabel(请输入文件名：);p1.a
27、dd(jt1);JPanel p2 = new JPanel();p2.add(new JLabel(文件内容：);p2.add(jspa);JPanel p3 = new JPanel();p3.add(b1);p3.add(b2);p3.add(b3);getContentPane().add(p1);getContentPane().add(p2);getContentPane().add(p3);setVisible(true);public void actionPerformed(ActionEvent ee) if (ee.getSource() = b3) dispose();
28、System.exit(0);if (ee.getSource() = b1)writer();if (ee.getSource() = b2)reader();void writer() String s1, s2;s1 = jt1.getText().trim();if (s1.equals() JOptionPane.showMessageDialog(null, 没有输入文件名);jt1.requestFocus(); else s2 = jt2.getText().trim();char s22 = s2.toCharArray();try FileOutputStream file
29、 = new FileOutputStream(s1);for (int i = 0; i s22.length; i+)file.write(s22i);file.close(); catch (IOException ie) jt1.setText();jt2.setText();void reader() String s1, s2 = ;s1 = jt1.getText().trim();if (s1.equals() JOptionPane.showMessageDialog(null, 没有输入文件名);jt1.requestFocus(); elsetry FileInputSt
30、ream file = new FileInputStream(s1);int c;while (c = file.read() != -1)s2 = s2 + (char) c;jt2.setText(s2);file.close(); catch (IOException ie) jt1.setText();public static void main(String args) new readerbyte();import java.io.*;import java.awt.*;import java.awt.event.*;import javax.swing.*;public cl
31、ass readerbyte extends JFrame implements ActionListener JButton b1, b2, b3;JTextField jt1;JTextArea jt2;readerbyte() setTitle(FileInputStream-FileOutputStream演示);getContentPane().setLayout(new FlowLayout();this.setDefaultLookAndFeelDecorated(true);this.setSize(450, 350);b1 = new JButton(写入);b2 = new
32、 JButton(读取);b3 = new JButton(退出);b1.addActionListener(this);b2.addActionListener(this);b3.addActionListener(this);jt1 = new JTextField(10);jt2 = new JTextArea(10, 30);jt2.setLineWrap(true);jt2.setWrapStyleWord(true);JScrollPane jspa = new JScrollPane(jt2);JPanel p1 = new JPanel();p1.add(new JLabel(
33、请输入文件名：);p1.add(jt1);JPanel p2 = new JPanel();p2.add(new JLabel(文件内容：);p2.add(jspa);JPanel p3 = new JPanel();p3.add(b1);p3.add(b2);p3.add(b3);getContentPane().add(p1);getContentPane().add(p2);getContentPane().add(p3);setVisible(true);public void actionPerformed(ActionEvent ee) if (ee.getSource() = b
34、3) dispose();System.exit(0);if (ee.getSource() = b1)writer();if (ee.getSource() = b2)reader();void writer() String s1, s2;s1 = jt1.getText().trim();if (s1.equals() JOptionPane.showMessageDialog(null, 没有输入文件名);jt1.requestFocus(); else s2 = jt2.getText().trim();char s22 = s2.toCharArray();try FileWrit
35、er file = new FileWriter(s1);for (int i = 0; i s22.length; i+)file.write(s22i);file.close(); catch (IOException ie) jt1.setText();jt2.setText();void reader() String s1, s2 = ;s1 = jt1.getText().trim();if (s1.equals() JOptionPane.showMessageDialog(null, 没有输入文件名);jt1.requestFocus(); elsetry FileReader file = new FileReader(s1);int c;while (c = file.read() != -1)s2 = s2 + (char) c;jt2.setText(s2);file.close(); catch (IOException ie) jt1.setText();public static void main(String args) new readerbyte();