实验7 Java高级I/O流程序设计

一、实验目的

 1、了解流、输入/输出流的概念。

  2、掌握常见的输入/输出流类及其主要方法。

  3、掌握用I/O流实现文件读/写的方法。

二、实验内容

1．编写程序将从键盘上输入的一行内容写入到文件copyfile.txt中，文件的保存位置自己确定。

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Scanner;

public class Test1 {
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		String str=in.next();
		//将字符串转化为byte数组
		byte[] b=str.getBytes();
		//创建输出流
		FileOutputStream f=null;
		try {
			f=new FileOutputStream("C:\JavaExercise\copyfile.txt");
			//开始写
			f.write(b);
			//输出流最后要刷新
			f.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}catch(IOException e) {
			e.printStackTrace();
		}finally {
			//关闭流
			try {
				f.close();
			}catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

2. 选择一个含有中文注释的.java文件，使用FileInputStream和FileReader分别读取文件，并把内容显示在控制台上。然后使用FileOutputStream和FileWriter将文件分别将文件复制到另一个文件copyfile1.txt和 copyfile2.txt中，文件的保存位置自己确定。

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class Test2_1 {
	public static void main(String[] args) {
		//先创建流
		FileInputStream fi=null;
		FileOutputStream fo=null;
		try {
			fi=new FileInputStream("D:\Users\Administrator\eclipse-workspace\FirstProject\src\com\java\exer7\Test1.java");
			fo=new FileOutputStream("C:\JavaExercise\copyfile2.txt");
			//边读边拷贝
			//准备byte数组
			byte[] b=new byte[1024];
			int readCount=0;
			while((readCount=fi.read(b))!=-1) {
				System.out.println(new String(b, 0, readCount));
				fo.write(b);
			}
			//刷新输出流
			fo.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}catch(IOException e) {
			e.printStackTrace();
		}finally {
			if(fi!=null) {
				try {
					fi.close();
				}catch(IOException e) {
					e.printStackTrace();
				}
			}
			if(fo!=null) {
				try {
					fi.close();
				}catch(IOException e){
					e.printStackTrace();
				}
			}
		}
	}
}

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Test2_2 {
	 public static void main(String[] args) {
	        //先创建流
	        FileReader fileReader = null;
	        FileWriter fileWriter = null;
	        try {
	            fileReader = new FileReader("D:\Users\Administrator\eclipse-workspace\FirstProject\src\com\java\exer7\Test1.java");
	            fileWriter = new FileWriter("C:\JavaExercise\copyfile1.txt");
	            //准备char数组
	            char[] chars = new char[4];
	            int readCount = 0;
	            //边读边写
	            while((readCount = fileReader.read(chars)) != -1){
	                System.out.print(new String(chars,0,readCount));
	                fileWriter.write(chars);
	            }
	            //刷新
	            fileWriter.flush();
	        } catch (FileNotFoundException e) {
	            e.printStackTrace();
	        } catch (IOException e) {
	            e.printStackTrace();
	        }finally {
	            if(fileReader != null){
	                try {
	                    fileReader.close();
	                } catch (IOException e) {
	                    e.printStackTrace();
	                }
	            }
	            if (fileWriter != null){
	                try {
	                    fileWriter.close();
	                } catch (IOException e) {
	                    e.printStackTrace();
	                }
	            }
	        }

	    }
}

3．利用上机6中第3题 的Book类，创建10个相应的对象，写入到文件book2.dat中；再从文件book2.dat中读出copy到文件book3.dat中。

import java.io.Serializable;
import java.util.*;

public class Book implements Comparable, Serializable {
    private String isbn;
    private String title;
    private String author;
    private final static Book[] books = generateData();

    public static Book[] generateData () {
        Book[] books = new Book[10];
        for (int i = 0; i < 10; i++) {
            Book book = new Book(i + 1 + "", "书本" + i, "biubiu");
            books[i] = book;
        }
        return books;
    }

    public static void linkedList() {
        List bookLinkedList = new LinkedList<>();
        for (int i = 0; i < books.length; i++) {
            bookLinkedList.add(books[i]);
        }
        bookLinkedList.stream().forEach(System.out::println);
    }

    public static void arrayList() {
        List bookArrayList = new ArrayList<>();
        for (int i = 0; i < books.length; i++) {
            bookArrayList.add(books[i]);
        }
        bookArrayList.stream().forEach(System.out::println);
    }

    public static void hashSet() {
        Set bookHashSet = new HashSet<>();
        for (int i = 0; i < books.length; i++) {
            bookHashSet.add(books[i]);
        }
        bookHashSet.stream().forEach(System.out::println);
    }

    public static void hasMap() {
        Map bookHashMap = new HashMap<>();
        for (int i = 0; i < books.length; i++) {
            bookHashMap.put(books[i].isbn,books[i]);
        }
        for (String key : bookHashMap.keySet()) {
            System.out.println(bookHashMap.get(key));
        }
    }

    public static void treeSet() {
        TreeSet treeSet = new TreeSet();
        for (int i = 0; i < books.length; i++) {
            treeSet.add(books[i]);
        }
        treeSet.stream().forEach(System.out::println);
    }


    public String getIsbn() {
        return isbn;
    }

    public void setIsbn(String isbn) {
        this.isbn = isbn;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public Book(String isbn, String title, String author) {
        this.isbn = isbn;
        this.title = title;
        this.author = author;
    }

    @Override
    public String toString() {
        return "Book{" +
                "isbn='" + isbn + ''' +
                ", title='" + title + ''' +
                ", author='" + author + ''' +
                '}';
    }

    @Override
    public int compareTo(Book o) {
        return this.isbn.compareTo(o.isbn);
    }

    public static void main(String[] args) {
        System.out.println("linkedList");
        linkedList();
        System.out.println("arrayList");
        arrayList();
        System.out.println("hashSet");
        hashSet();
        System.out.println("hasMap");
        hasMap();
        System.out.println("treeSet");
        treeSet();
    }
}