Java基础复习

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

public class TestFileOutputStream {
    public static void main(String[] args) throws IOException {

        try(
                FileOutputStream fos = new FileOutputStream("output.txt",true);
                ){
            for (int i = 0; i < 10; i++) {
                fos.write("hello,world!".getBytes());
                fos.write("\n".getBytes());
            }

        }catch (IOException e){
            e.printStackTrace();
        }

    }
}

import java.io.*;

public class TestFileInputStream {
    public static void main(String[] args) {
        try (
                FileInputStream fis = new FileInputStream("input.txt");
                FileOutputStream fos = new FileOutputStream("output.txt");
        ) {
//            copyByByte(fis,fos);

            copyByBytes(fis,fos);

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 不使用缓冲区复制
     * @param is
     * @param os
     */
    private static void copyByByte(InputStream is, OutputStream os) throws IOException {
        int data;
        while ((data=is.read())!=-1){
            os.write(data);
        }
    }

    /**
     * 使用缓冲区复制
     * @param is
     * @param os
     */
    private static void copyByBytes(InputStream is, OutputStream os) throws IOException {
        byte[] bytes=new byte[1024];
        int len;
        while ((len=is.read(bytes))!=-1){
            os.write(bytes,0,len);
        }

    }
}

import java.io.*;


/*
给定一个源文件夹，将其复制到E:盘根目录下
 */
public class CopyDirectory {

    public static void main(String[] args) {
        File src = new File("E:\\");

//        System.out.println(srcDir.getName());
        File dest = new File("E:\\temp");

        copy(src,dest);

    }

    private static void copy(File src, File dest) {
        if(src.isFile()){
            //src是一个文件
            copyFile(src,new File(dest,src.getName()));
        }else {
            //src是一个目录
            //新建目标目录
            File newFolder = new File(dest, src.getName());
            if(!newFolder.exists()){
                newFolder.mkdirs();
            }
            File[] files = src.listFiles();
            for(File f:files){
                copy(f,newFolder);
            }
        }


    }

    private static void copyFile(File srcFile, File destFile) {
        try (
                BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));
                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));
        ) {

            byte[] bytes=new byte[2048];
            int len;
            while ((len=bis.read(bytes))!=-1){
                bos.write(bytes,0,len);
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.huangbei.io.input;

import java.io.*;

public class TestInputStreamReader {
    public static void main(String[] args) {

//        gb2312编码的txt转utf-8
        try (
                FileInputStream fis = new FileInputStream("斗破苍穹.txt");
                InputStreamReader isr=new InputStreamReader(fis,"gb2312");

                OutputStreamWriter osw=new OutputStreamWriter(new FileOutputStream("斗破苍穹(copy).txt"),"utf-8");
                ) {


            char[] chars = new char[2048];
            int len;
            while ((len=isr.read(chars))!=-1){
                osw.write(chars,0,len);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.huangbei.io.output;

import javafx.beans.binding.ObjectExpression;

import java.io.*;
import java.util.ArrayList;

public class TestObjectStream {
    public static void main(String[] args) throws IOException, ClassNotFoundException {

//        write();
        read();
    }

    private static void write() throws IOException {
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("object.data"));

        ArrayList<Student> list = new ArrayList<>();
        list.add(new Student("乔峰", 40));
        list.add(new Student("段誉", 25));
        list.add(new Student("虚竹", 27));
        objectOutputStream.writeObject(list);
    }
    private static void read() throws IOException, ClassNotFoundException {
        ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream("object.data"));
        Object o = objectInputStream.readObject();
        System.out.println(o);
    }
}
class Student implements Serializable{
    static final long serialVersionUID=7102412401203991L;

    private String name;
    private int age;
    private transient int id;

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public Student() {

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", id=" + id +
                '}';
    }
}