Java實現文件讀取和寫入過程解析

package com.io;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * @auther:：9527
 * @Description: 嘗試
 * @program: shi_yong
 * @create: 2019-07-31 17:11
 */
public class Tyy {
  public static void main(String[] args) {
    //實例化對象
   Tyy tyy = new Tyy();
   //用一個byte[]接受數據
   byte[] bytes=tyy.read("d:/ak.txt");
   //將接受到的數據傳入寫入方法
   tyy.write("d:/hello.txt",bytes);

  }

  //讀取方法，設定傳參是文件的String路徑，返回一個byte[]數組
  public byte[] read(String str) {
    byte[] bytes = new byte[0];
    FileInputStream fis = null;
    try {
      fis = new FileInputStream(str);
      int read;
      bytes = new byte[1024000];
      System.out.println("內容讀取中...........");
      while ((read = fis.read(bytes)) != -1) {
        for (int i = 0; i < read; i++) {
          System.out.print((char) bytes[i]);
        }
        System.out.println("\n內容讀取完畢");
      }
      return bytes;
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      try {
        fis.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
    return bytes;
  }

  //寫入方法，需要兩個參數，一是寫入路徑，一是寫入內容
  public void write(String string,byte[] bytes) {
    System.out.println("文件寫入中-----");
    FileOutputStream fos = null;

    try {
      fos = new FileOutputStream(string);
      try {
        fos.write(bytes);
      } catch (IOException e) {
        e.printStackTrace();
      }
      System.out.println("文件寫入完畢");

    } catch (FileNotFoundException e) {
      e.printStackTrace();
    }finally {
      try {
        fos.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}