package top.qaqaq.java.P592;

import org.junit.jupiter.api.Test;

import java.io.*;

/**
 * 测试FileInputStream和FileOutputStream的使用
 *
 * 结论：
 * 1. 对于文本文件(.txt,.java,.c,.cpp)，使用字符流处理
 * 2. 对于非文本文件(.jpg,.mp3,.mp4,.avi,.doc,.ppt,...)，使用字节流处理
 *
 * @author RichieZhang
 * @create 2022-10-29 下午 10:01
 */
public class FileInputOutputStreamTest {

    //使用字节流FileInputStream处理文本文件，可能出现乱码。
    @Test
    public void testFileInputStream() {
        FileInputStream fis = null;

        try {
            //1. 造文件
            File file = new File("hello.txt");

            //2. 造流
            fis = new FileInputStream(file);

            //3. 读数据
            byte[] buffer = new byte[5];
            int len;//记录每次读取的字节的个数
            while ((len = fis.read(buffer)) != -1){

                String str = new String(buffer,0,len);
                System.out.print(str);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(fis != null){
                //4. 关闭资源
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }
    }

    /*
    实现对图片的复制操作
     */
    @Test
    public void testFileInputOutputStream() {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            //
            File strFile = new File("爱情与友情.jpg");
            File destFile = new File("爱情与友情2.jpg");

            //
            fis = new FileInputStream(strFile);
            fos = new FileOutputStream(destFile);

            //复制的过程
            byte[] buffer = new byte[5];
            int len;
            while ((len = fis.read(buffer)) != -1){
                fos.write(buffer,0,len);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fos != null){
                //
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    //指定路径下文件的复制
    public void copyFile(String srcPath, String destPath){
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            //
            File strFile = new File(srcPath);
            File destFile = new File(destPath);

            //
            fis = new FileInputStream(strFile);
            fos = new FileOutputStream(destFile);

            //复制的过程
            byte[] buffer = new byte[1024];
            int len;
            while ((len = fis.read(buffer)) != -1){
                fos.write(buffer,0,len);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fos != null){
                //
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    @Test
    public void testCopyFile(){

        long start = System.currentTimeMillis();

        String srcPath = "C:\\Users\\ZRich\\Documents\\我的文档\\PDF.pdf";
        String destPath = "PDF.pdf";

//        String srcPath = "hello.txt";
//        String destPath = "hello3.txt";

        copyFile(srcPath,destPath);

        long end = System.currentTimeMillis();

        System.out.println("复制操作花费的时间为：" + (end - start));//614
    }
}