java文件操作之字节流与字符流

字节流需要用到的类：

 字符流需要用到的类：

说一下读写操作大致过程：

 一般如果纯文本，我们最好用字符流，但是如果图片，这种按照字节拼接，就采用字节流

下面看一下代码实例：我们从一张盘拷贝一张照片到另外一张盘

import java.io.*;

public class ImageCopy {
    public static void main(String[] args) {
        File srcFile = new File("F:\\pxx\\1.jpg");
        File destFile = new File("E:\\haha.jpg");
        copyImage(srcFile,destFile);
    }

    //这个采用一边读，一边写的思路来做
    public static void copyImage(File srcFile, File destFile)  {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            fis = new FileInputStream(srcFile);
            fos = new FileOutputStream(destFile);
            byte[] buff = new byte[1024];
            int len = 0;
            while((len = fis.read(buff)) != -1) {
                fos.write(buff,0,len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

然后我们看一下对于一个文本拷贝的代码：关于乱码问题，可以看一下我字符集编码问题：

//采用字符流来读取文本操作
    public static void copyText(File srcFile,File destFile) {
        InputStreamReader fr = null;
        OutputStreamWriter fw = null;
        try {
            fr = new InputStreamReader(new FileInputStream(srcFile),"gbk");
          //  fw = new FileWriter(destFile);
            fw = new OutputStreamWriter(new FileOutputStream(destFile),"gbk");
            char[] buff = new char[1024];
            int len = 0;
            while((len = fr.read(buff)) != -1) {
                System.out.println("读取到的长度:" + len);
                fw.write(buff,0,len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fr.close();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    fw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }