package com.io.stream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class TestFileInputStream {
    //定義一個(gè)流對(duì)象
    private static FileInputStream fis;
    public static void main(String[] args) {
        try {
            //1、 創(chuàng)建流對(duì)象.參數(shù)可以是一個(gè)File類、String字符串表示的文件路徑
            fis = new FileInputStream("E:\\aaa.txt");//在e盤下有一個(gè)aaa.txt的文件夾，內(nèi)容為（abcdefg）
            //2、使用流的方法對(duì)文件進(jìn)行讀
            while (true) {
                int read = fis.read();//注意這里返回的是int類型，代表是字符的ASCII值
                if (read==-1) {//讀到最后會(huì)返回-1，退出條件
                    break;
                }
                System.out.println(read);
            }
        } catch (FileNotFoundException e) {//異常細(xì)?；?，不同異常可以選擇不同的處理方式
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                //3、關(guān)閉流
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Arrays;
public class TestFileInputStream2 {
    private static FileInputStream fis;
    public static void main(String[] args) {
        try {
            fis = new FileInputStream("IO流\\aaa.txt");
            //準(zhǔn)備一個(gè)byte數(shù)組
            byte[] b= new byte[3];
            int readNum = 0;
            while (true) {
                //先進(jìn)行讀操作。
                readNum=fis.read(b);
                //判斷
                if (readNum == -1) {
                    break;
                }
                //將字符數(shù)組轉(zhuǎn)為String,后面兩個(gè)參數(shù)為起始位置，和長(zhǎng)度
                String str = new String(b, 0, readNum);
                System.out.println(str);
            }
            /*輸出
				abc
				def
				g
			*/
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                //關(guān)閉流
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

public class TestFileInputStream3 {
    public static void main(String[] args) throws IOException {
        FileInputStream fis = new FileInputStream("IO流\\aaa.txt");
        byte[] bytes = new byte[fis.available()];//創(chuàng)建一個(gè)和文件字符數(shù)量一樣大的byte數(shù)組，文件不能太大。
        fis.read(bytes);
        System.out.println(new String(bytes));//b轉(zhuǎn)為字符串，輸出abcdefg
    }
}

package com.io.stream.output;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
/**
 * @Author cyh
 * @Date 2021/8/7 17:21
 */
public class Test1 {
    private static FileOutputStream fos;
    public static void main(String[] args) {
        try {
            //新建一個(gè)輸出流，參數(shù)是輸出的路徑，最后的為文件名。
            fos = new FileOutputStream("IO流\\bbb.txt");
            //新建一個(gè)byte數(shù)組，里面對(duì)應(yīng)的是abcd的ascii值
            byte[] bytes = {97, 98, 99, 100,101,127}; //注意byte的范圍是-128~127
            //輸出流調(diào)用write方法寫入byte數(shù)組，以文件形式保存到上面的路徑
            fos.write(bytes);
            //寫完之后，一定要刷新
            fos.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

//新建一個(gè)輸出流，參數(shù)是輸出的路徑，最后的為文件名。增加true表示開(kāi)啟追加寫
fos = new FileOutputStream("IO流\\bbb.txt",true);

package com.io.stream.copy;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
/**
 * @Author cyh
 * @Date 2021/8/7 17:53
 */
public class TestCopy {
    private static FileInputStream fis;
    private static FileOutputStream fos;
    public static void main(String[] args) {
        try {
            //創(chuàng)建一個(gè)輸入流
            fis = new FileInputStream("D:\\edgeDownload\\VSCodeUserSetup-x64-1.55.0.exe");
            //創(chuàng)建一個(gè)輸出流
            fos = new FileOutputStream("C:\\Users\\PC\\Desktop\\copy\\b\\VSCodeUserSetup-x64-1.55.0.exe");
            //核心，一邊讀、一邊寫
            byte[] bytes = new byte[1024*1024];//1MB,一次最多拷貝1MB
            int readNum=0;
            while((readNum=fis.read(bytes))!=-1){
                fos.write(bytes,0,readNum);//將bytes全部寫入
            }
            //刷新
            fos.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //資源要分開(kāi)釋放，不然一個(gè)出錯(cuò)會(huì)導(dǎo)致另一個(gè)無(wú)法釋放
            try {
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}