JAVA IO流知识点全总结

Java IO流是Java进行数据输入输出操作的重要部分，以下是一些常见的IO流知识点及其简单解释和示例代码：

1. 字节流

   • InputStream 和 OutputStream

   • 示例代码：

     
     
     
     InputStream is = new FileInputStream("file.txt");
     int byteContent;
     while ((byteContent = is.read()) != -1) {
         // 处理读取的字节
     }
     is.close();
      
     OutputStream os = new FileOutputStream("file.txt");
     String content = "Hello, World!";
     os.write(content.getBytes());
     os.close();

2. 字符流

   • Reader 和 Writer

   • 示例代码：

     
     
     
     Reader reader = new FileReader("file.txt");
     int charContent;
     while ((charContent = reader.read()) != -1) {
         // 处理读取的字符
     }
     reader.close();
      
     Writer writer = new FileWriter("file.txt");
     String content = "Hello, World!";
     writer.write(content);
     writer.close();

3. 缓冲流

   • BufferedInputStream，BufferedOutputStream，BufferedReader，BufferedWriter

   • 示例代码：

     
     
     
     BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
     String line;
     while ((line = reader.readLine()) != null) {
         // 处理读取的行
     }
     reader.close();
      
     BufferedWriter writer = new BufferedWriter(new FileWriter("file.txt"));
     writer.write("Hello, World!");
     writer.close();

4. 对象流

   • ObjectInputStream，ObjectOutputStream

   • 示例代码：

     
     
     
     ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("object.txt"));
     oos.writeObject(new MyClass());
     oos.close();
      
     ObjectInputStream ois = new ObjectInputStream(new FileInputStream("object.txt"));
     MyClass myObject = (MyClass) ois.readObject();
     ois.close();

5. 标准输入输出流

   • System.in，System.out，System.err

   • 示例代码：

     
     
     
     Scanner scanner = new Scanner(System.in);
     System.out.println("请输入内容：");
     String content = scanner.nextLine();
     System.out.println("您输入的内容是：" + content);
     scanner.close();

6. 文件流

   • FileInputStream，FileOutputStream，FileReader，FileWriter
   • 示例代码已在字节流和字符流部分给出。

7. 数据流

   • DataInputStream，DataOutputStream

   • 示例代码：

     
     
     
     DataOutputStream dos = new DataOutputStream(new FileOutputStream("data.txt"));
     dos.writeDouble(123.456);
     dos.writeInt(789);
     dos.close();