Java小记（第二周）

在本周利用课下时间学习了io流以及mysql的通用语法和JDBC、mybatis，并且将上周的没有加上io流的图书管理系统，用io流进行了输入输出

以下是我整理的io流的部分我认为比较重要的知识点

输入流：InputStream
read(byte[] b)
从输入流读取一些字节数，并将它们存储到缓冲区 b 。
read(byte[] b, int off, int len)
从输入流读取最多 len字节的数据到一个字节数组。
close()
关闭此输入流并释放与流相关联的任何系统资源。

输出流：OutputStream
write(byte[] b)
将 b.length字节从指定的字节数组写入此输出流。
write(byte[] b, int off, int len)
从指定的字节数组写入 len个字节，从偏移 off开始输出到此输出流。
write(int b)
将指定的字节写入此输出流。

flush()
刷新此输出流并强制任何缓冲的输出字节被写出。

close()
关闭此输出流并释放与此流相关联的任何系统资源。

以下是我写的图书管理系统：

基本目录：

 在上周的基础上进行了改造，加上了下面这些，其余的与上周基本类似

Filebook

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package file;

import bean.Book;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class FileBook {
    public FileBook() {
    }

    public void saveBook(List l) {
        File fb = new File("d:/zzm/Book.txt");
        FileWriter fwb = null;

        try {
            fwb = new FileWriter(fb);
        } catch (IOException var8) {
            System.out.println(var8.getMessage());
        }

        PrintWriter p = new PrintWriter(fwb);
        Iterator it = l.iterator();

        while(it.hasNext()) {
            Book b = (Book)it.next();
            String str = b.getId() + "," + b.getName() + "," + b.getAuthor() + "," + b.getcbs() + "," + b.getDate() + "," + b.getsum() + "," + b.getPrice() + ",";
            p.println(str);
            p.flush();
        }

        p.close();
    }

    public List selectBook() {
        List l = new ArrayList();
        File fb = new File("d:/zzm/Book.txt");
        FileReader frb = null;

        try {
            frb = new FileReader(fb);
        } catch (IOException var15) {
            System.out.println("文件未找到");
        }

        BufferedReader br = new BufferedReader(frb);
        String str = null;

        try {
            str = br.readLine();
        } catch (IOException var14) {
            System.out.println(var14.getMessage());
        }

        while(str != null) {
            Book c = new Book();
            String[] s = str.split(",");
            c.setId(s[0]);
            c.setName(s[1]);
            c.setAuthor(s[2]);
            c.setCbs(s[3]);
            c.setDate(s[4]);
            int sum = Integer.parseInt(s[5]);
            c.setsum(sum);
            double price = Double.parseDouble(s[6]);
            c.setPrice(price);
            l.add(c);

            try {
                str = br.readLine();
            } catch (IOException var13) {
                System.out.println(var13.getMessage());
            }
        }

        try {
            br.close();
        } catch (IOException var12) {
            System.out.println(var12.getMessage());
        }

        return l;
    }

    public void add(Book b) {
        String str = b.getId() + "," + b.getName() + "," + b.getAuthor() + "," + b.getcbs() + "," + b.getDate() + "," + b.getsum() + "," + b.getPrice() + ",";
        File fb = new File("d:/zzm/Book.txt");
        FileWriter fwb = null;

        try {
            fwb = new FileWriter(fb, true);
        } catch (IOException var6) {
            System.out.println(var6.getMessage());
        }

        PrintWriter p = new PrintWriter(fwb);
        p.println(str);
        p.flush();
        p.close();
    }
}

Filereader

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package file;

import bean.Readin;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class FileReadin {
    public FileReadin() {
    }

    public void saveReadin(List l) {
        File fl = new File("d:/zzm/Readin.txt");
        FileWriter fwl = null;

        try {
            fwl = new FileWriter(fl);
        } catch (IOException var8) {
            System.out.println(var8.getMessage());
        }

        PrintWriter p = new PrintWriter(fwl);
        Iterator it = l.iterator();

        while(it.hasNext()) {
            Readin b = (Readin)it.next();
            String str = b.getXh() + "," + b.getRname() + "," + b.getXy() + "," + b.getMc() + ",";
            p.println(str);
            p.flush();
        }

        p.close();
    }

    public List selectReadin() {
        List l = new ArrayList();
        File fl = new File("d:/zzm/Readin.txt");
        FileReader frl = null;

        try {
            frl = new FileReader(fl);
        } catch (IOException var12) {
            System.out.println("文件未找到");
        }

        BufferedReader br = new BufferedReader(frl);
        String str = null;

        try {
            str = br.readLine();
        } catch (IOException var11) {
            System.out.println(var11.getMessage());
        }

        while(str != null) {
            Readin c = new Readin();
            String[] j = str.split(",");
            c.setXh(j[0]);
            c.setRname(j[1]);
            c.setXy(j[2]);
            c.setMc(j[3]);
            l.add(c);

            try {
                str = br.readLine();
            } catch (IOException var10) {
                System.out.println(var10.getMessage());
            }
        }

        try {
            br.close();
        } catch (IOException var9) {
            System.out.println(var9.getMessage());
        }

        return l;
    }

    public void add(Readin b) {
        String str = b.getXh() + "," + b.getRname() + "," + b.getXy() + "," + b.getMc() + ",";
        File fb = new File("d:/zzm/Readin.txt");
        FileWriter fwl = null;

        try {
            fwl = new FileWriter(fb, true);
        } catch (IOException var6) {
            System.out.println(var6.getMessage());
        }

        PrintWriter p = new PrintWriter(fwl);
        p.println(str);
        p.flush();
        p.close();
    }
}

Filebooklook

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package file;

import bean.Booklook;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class FileBooklook {
    public FileBooklook() {
    }

    public void savebooklook(List l) {
        File fl = new File("d:/zzm/booklook.txt");
        FileWriter fwl = null;

        try {
            fwl = new FileWriter(fl);
        } catch (IOException var8) {
            System.out.println(var8.getMessage());
        }

        PrintWriter p = new PrintWriter(fwl);
        Iterator it = l.iterator();

        while(it.hasNext()) {
            Booklook b = (Booklook)it.next();
            String str = b.getXh() + "," + b.getRname() + "," + b.getId() + "," + b.getName() + "," + b.getJdate() + "," + b.getRname() + "," + b.getGdate() + ",";
            p.println(str);
            p.flush();
        }

        p.close();
    }

    public List selectbooklook() {
        List l = new ArrayList();
        File fl = new File("d:/zzm/booklook.txt");
        FileReader frl = null;

        try {
            frl = new FileReader(fl);
        } catch (IOException var12) {
            System.out.println("文件未找到");
        }

        BufferedReader br = new BufferedReader(frl);
        String str = null;

        try {
            str = br.readLine();
        } catch (IOException var11) {
            System.out.println(var11.getMessage());
        }

        while(str != null) {
            Booklook c = new Booklook();
            String[] k = str.split(",");
            c.setXh(k[0]);
            c.setRname(k[1]);
            c.setId(k[2]);
            c.setName(k[3]);
            c.setJdate(k[4]);
            c.setRname(k[5]);
            c.setGdate(k[6]);
            l.add(c);

            try {
                str = br.readLine();
            } catch (IOException var10) {
                System.out.println(var10.getMessage());
            }
        }

        try {
            br.close();
        } catch (IOException var9) {
            System.out.println(var9.getMessage());
        }

        return l;
    }

    public void add(Booklook b) {
        String str = b.getXh() + "," + b.getRname() + "," + b.getId() + "," + b.getName() + "," + b.getJdate() + "," + b.getRname() + "," + b.getGdate() + ",";
        File fb = new File("d:/zzm/booklook.txt");
        FileWriter fwl = null;

        try {
            fwl = new FileWriter(fb, true);
        } catch (IOException var6) {
            System.out.println(var6.getMessage());
        }

        PrintWriter p = new PrintWriter(fwl);
        p.println(str);
        p.flush();
        p.close();
    }
}

工具类，接受控制台的数据

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package util;

import java.util.Scanner;

public class CMDUtil {
    private static Scanner sc;

    static {
        sc = new Scanner(System.in);
    }

    public CMDUtil() {
    }

    public static String getString() {
        String s = "";
        if (sc.hasNext()) {
            s = sc.nextLine();
        }

        return s;
    }

    public static int getInt() {
        int i = -1;
        boolean b = true;

        while(b) {
            try {
                String s = getString();
                i = Integer.parseInt(s);
                b = false;
            } catch (Exception var3) {
                System.out.println("请重新输入");
            }
        }

        return i;
    }

    public static char getChar() {
        String s = getString();
        s = s.toUpperCase();
        char c = s.charAt(0);
        return c;
    }

    public static double getDouble() {
        double i = -1.0;
        boolean b = true;

        while(b) {
            try {
                String s = getString();
                i = Double.parseDouble(s);
                b = false;
            } catch (Exception var4) {
                System.out.println("请重新输入");
            }
        }

        return i;
    }
}

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