Java学习笔记——I/O流

朝辞白帝彩云间，千里江陵一日还。
两岸猿声啼不尽，轻舟已过万重山。

　　　　　　　　　　　　　　——早发白帝城

我们老师写代码有个特点，就是简洁。每一句的意图都十分明确。所以他讲课的速度也比较快。

跑题了，说说I/O流:

1、字节输入流

2、字符输入流

3、字节输出流

4、字符输出流

上代码：

 public class FileInputStreamAndFileoutputSteamDemo {

     public static void main(String[] args) throws IOException {

         FileOutputStream fos = new FileOutputStream("/home/yanshaochen/public/abc.txt");

         byte[] bytes = new byte[];

         bytes = "金麟岂是池中物,一遇风云变化龙".getBytes();

         fos.write(bytes);

         fos.close();

         FileInputStream fis = new FileInputStream("/home/yanshaochen/public/abc.txt");

         String str = "";

         int data;

         while ((data = fis.read(bytes)) != -) {

             str += new String(bytes, , data);

         }

         System.out.println(str);

         fis.close();

     }

 }

 public class WriterAndReader {

     public static void main(String[] args) throws IOException {

         String path = "/home/yanshaochen/public/abc.txt";

         Writer wt = new FileWriter(path);

         String str = "AAAAA";

         wt.write(str);

         wt.close();

         Reader rd = new FileReader(path);

         char[] chars = new char[];

         int data;

         str = "";

         while ((data = rd.read(chars))!=-) {

             str += new String(chars, , data);

         }

         System.out.println(str);

         rd.close();

     }

 }

带缓冲区的字符输入输出流

 public class BufferedReaderAndBufferedWriter {

     public static void main(String[] args) throws IOException {

         Writer fw = new FileWriter("/home/yanshaochen/public/abc.txt");

         BufferedWriter bw = new BufferedWriter(fw);

         String str = "AAAAAAAA";

         bw.write(str);

         bw.newLine();

         bw.close();

         Reader fr =new FileReader("/home/yanshaochen/public/abc.txt");

         BufferedReader br = new BufferedReader(fr);

         while ((str = br.readLine())!= null) {

             System.out.println(str);

         }

         br.close();

     }

 }

字节流读写二进制

 public class DataInputStreamDemo {

     public static void main(String[] args) throws IOException {

         //原始地址

         InputStream is = new FileInputStream("/home/yanshaochen/图片/2017-05-06 15-12-02屏幕截图.png");

         DataInputStream dis = new DataInputStream(is);

         //目标地址

         OutputStream os = new FileOutputStream("/home/yanshaochen/public/2017-05-06 15-12-02屏幕截图.png");

         DataOutputStream dos = new DataOutputStream(os);

         byte[] bytes = new byte[];

         int data;

         while((data = dis.read(bytes)) != -){

             dos.write(bytes,,data);

         }

         System.out.println("copy ok!");

         dos.close();

         dis.close();

     }

 }