---
title: Java IO
category: Java
tag:
  - Java IO
  - Java
---


IO !UNIX ~

_//_

## 

I/O  I/O 

## I/O

###  I/O?

I/O**I**nput/**O**utpu **** 

** I/O**

. 5 

![](https://img-blog.csdnimg.cn/20190624122126398.jpeg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9pcy1jbG91ZC5ibG9nLmNzZG4ubmV0,size_16,color_FFFFFF,t_70)





** I/O **

** I/O**

 **User space**  **Kernel space ** 

 IO 



 IO 

 IO  **** 

 ** IO**  ** IO**

** IO  IO  IO  IO **

 I/O 

1.  I/O 
2. 

###  IO ?

UNIX  IO  5  ** I/O**** I/O****I/O **** I/O** ** I/O**

 5  IO 

## Java  3  IO 

### BIO (Blocking I/O)

**BIO  IO ** 

 IO  read 

![Tomcat & Jetty](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/6a9e704af49b4380bb686f0c96d33b81~tplv-k3u1fbpfcp-watermark.image)

 BIO  I/O 

### NIO (Non-blocking/New I/O)

Java  NIO  Java 1.4  `java.nio`  `Channel` , `Selector``Buffer` NIO  N  Non-blocking New I/O   NIO 

Java  NIO  **I/O **Java  NIO  IO 



 ** IO **

![Tomcat & Jetty](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/bb174e22dbe04bb79fe3fc126aed0c61~tplv-k3u1fbpfcp-watermark.image)

 IO  read 

 IO  IO 

 IO ** I/O  CPU **

**I/O ** 

![](https://p6-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/88ff862764024c3b8567367df11df6ab~tplv-k3u1fbpfcp-watermark.image)

IO  select  read read  -> 

>  IO  selectepoll select 
>
> - **select ** 
> - **epoll ** linux 2.6  select  IO 

**IO  CPU **

Java  NIO ** ( Selector )**  ****

![](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/0f483f2437ce4ecdb180134270a00144~tplv-k3u1fbpfcp-watermark.image)

### AIO (Asynchronous I/O)

AIO  NIO 2Java 7  NIO  NIO 2, IO 

 IO 

![](https://p1-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/3077e72a1af049559e81d18205b56fd7~tplv-k3u1fbpfcp-watermark.image)

 AIO Netty  AIONetty  AIO  Linux 

 Java  BIONIOAIO

![](https://images.xiaozhuanlan.com/photo/2020/33b193457c928ae02217480f994814b6.png)

## 

-  Tomcat & Jetty
-  IOhttps://llc687.top/126.html
-  IO[https://www.jianshu.com/p/fa7bdc4f3de7](https://www.jianshu.com/p/fa7bdc4f3de7)
- 10  Java NIO https://www.cnblogs.com/crazymakercircle/p/10225159.html
- IO  | https://www.cnblogs.com/sheng-jie/p/how-much-you-know-about-io-models.html
- UNIX   1 API 6.2  IO