提问 要写实训报告从这些代码里面咋写啊 用到了哪些知识

Question

package cn.glutnn.jy03;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.LocalDate;
import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;

public class Jy200335 {

public static void main(String[] args) {

// //1.接收控制台的用户输入数据
String in = getInputs();
System.out.println(in);

    //2.根据用户的输入数据来创建文件夹
    Path dir=makeDir(in);

// System.out.println(dir.toAbsolutePath().toString());

    //3.在指定文件夹下创建文本文件
    Path file=makeFile(dir,in);

// //4.准备存入文本文件的书籍
Book b1=new Book("1001011", "书1", LocalDate.of(2001, 4, 13));
Book b2=new Book("1001012", "书2", LocalDate.of(2003, 5, 1));
Book b3=new Book("1001013", "书3", LocalDate.of(2010, 4, 23));
Book b4=new Book("1001014", "书4", LocalDate.of(2021, 8, 13));
Book b5=new Book("1001015", "书5", LocalDate.of(2011, 7, 22));
Book b6=new Book("1001015", "书6", LocalDate.of(2016, 8, 22));

    TreeSet<Book> books=new TreeSet<Book>(new MyComparable());
    books.add(b6);
    books.add(b5);
    books.add(b4);
    books.add(b3);
    books.add(b2);
    books.add(b1);
    

// for(Book book:books) {
// System.out.println(book);
//
// }

    //5.
    writeFile(file,books);
    
    //6.
    TreeSet<Book> bookset=readFile(file);
    System.out.println("读取到的文本内容如下：");
    for(Book book:bookset) {
        System.out.println(book);
    }

 }

private static TreeSet<Book> readFile(Path file) {
    
    TreeSet<Book> bookset = null;
    try(InputStream in=new FileInputStream(file.toFile());
        ObjectInputStream ois=new ObjectInputStream(in);) {
        bookset = (TreeSet<Book>) ois.readObject();
    } catch (FileNotFoundException e) {
        System.out.println("被读取的文本文件不存在！");
    } catch (ClassNotFoundException e) {
        System.out.println("强制类型转换失败！");
    } catch (IOException e) {
        System.out.println("指定文本文件读取失败！");
    }    
    
    return bookset;
}

private static void writeFile(Path file, TreeSet<Book> books) {        
    //追加数据写入到文本文件
    try(OutputStream io=new FileOutputStream(file.toFile());
            ObjectOutputStream oos=new ObjectOutputStream(io);) {    
        oos.writeObject(books);
        System.out.println("写文本文件成功！");
    } catch (FileNotFoundException e) {
        System.out.println("被写入的文本文件不存在！");
    } catch (IOException e) {

System.out.println(file.toAbsolutePath().toString()+"该文本文件写入失败！");
e.printStackTrace();
}
}

private static Path makeFile(Path dir, String in) {
    Path file=Paths.get(dir.toAbsolutePath().toString(),in.concat(".txt"));
    try {
        file = Files.createFile(file);
    } catch(FileAlreadyExistsException e){
        System.out.println("同名文本文件已经存在！");
    }catch (IOException e) {
        System.out.println("无法创建指定的文本文件！");
        file=null;
    }
    return file;
}

private static Path makeDir(String in) {
    Path dir = Paths.get(in);
    try {
        dir=Files.createDirectory(dir);
    } catch (FileAlreadyExistsException  e) {
        System.out.println("已经存在同名的文件夹！");
    }catch(IOException e) {
        System.out.println("无法创建指定文件夹！");
        dir=null;
    }    
    return dir;
}

private static String getInputs() {
    Scanner scanner = new Scanner(System.in);        
    boolean flag = false;
    String inputs = null;
    while (!flag) {
        System.out.println(">>>");
        inputs = scanner.next();
        Pattern pattern = null;
        //正则表达式：jy200[3|4][0-9]{2}
        flag = pattern.matches("^jy200[3|4][0-9]{2}$", inputs);

// System.out.println("flag的返回值为：" + flag);

        if (flag == true) {
            break;
        }else {
            System.err.println("你输入的数据格式错误，要重新输入！");
        }
    }

scanner.close();
return inputs;
}

Answer 1

基本输入输出IO流，对象流，TreeSet集合保存数据，目录创建，文件操作保存集合数据等技术。