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();
     }
 }