package com.example.demo.controller;

import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.*;

/**
 * 数据流
 */
@RestController
@RequestMapping("/")
public class StreamController {

    /**
     * 字符数据流
     */
    @GetMapping("/character")
    public void characterDemo() throws IOException {
        //CharArrayWriter用来接收数据
        CharArrayWriter charArrayWriter = new CharArrayWriter();
        charArrayWriter.write("cat1"); //可以是字符串或者下面的字节数组
        char[] char01 = {'c','a','t','2'};
        charArrayWriter.write(char01);

        char[] char02 = charArrayWriter.toCharArray(); //转字符数组
        System.out.print(char02);
        System.out.print("\r\n");
        CharArrayReader charArrayReader = new CharArrayReader(char02);
        CharArrayReader reader = new CharArrayReader(char02);
        while (charArrayReader.read() != -1){ //读数据
            System.out.print((char) reader.read());
        }
        System.out.print("\r\n");

        //推荐使用
        BufferedReader bufferedReader = new BufferedReader(new CharArrayReader(char02));
        System.out.print(bufferedReader.readLine());
    }


    /**
     * 字节数据流&文件流
     */
    @PostMapping("/byte")
    public void byteDemo(@RequestPart @RequestParam("file") MultipartFile file) throws IOException {
        String filename = file.getOriginalFilename(); //获取文件名
        byte[] fileContent = file.getBytes();
        FileOutputStream fileOutputStream = new FileOutputStream("test.txt");
        fileOutputStream.write(fileContent); //写入
        fileOutputStream.close(); //关闭

        File file2 = new File("test2.txt");
        File file2rename = new File("test2rename.txt");
        file2.renameTo(file2rename);

        if(file2.createNewFile() == false){
            System.out.print("文件新建失败");
        }
        file2.delete(); //删除
    }

}