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<!-- GFM-TOC -->
* [????](#????)
* [???????](#???????)
* [??????](#??????)
* [???????](#???????)
* [???????](#???????)
* [???????](#???????)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD>̲<EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD>̲<EFBFBD><CCB2><EFBFBD>)
* [<EFBFBD>ֽڲ<EFBFBD><EFBFBD><EFBFBD>](#<23>ֽڲ<D6BD><DAB2><EFBFBD>)
* [<EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [1. InetAddress](#1-inetaddress)
* [2. URL](#2-url)
* [3. Sockets](#3-sockets)
* [4. Datagram](#4-datagram)
* [NIO](#nio)
* [1. ?????](#1-?????)
* [2. ?????????](#2-?????????)
* [2.1 ???](#21-???)
* [2.2 ??????](#22-??????)
* [3. ????????????](#3-????????????)
* [4. ??<3F><>??????](#4-??<3F><>??????)
* [5. ???????????](#5-???????????)
* [5.1 ????? I/O](#51-?????-io)
* [5.2 ??????? I/O](#52-???????-io)
* [6. ????????](#6-????????)
* [1. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#1-<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [2. ͨ<EFBFBD><EFBFBD><EFBFBD>뻺<EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#2-ͨ<><CDA8><EFBFBD>뻺<EFBFBD><EBBBBA><EFBFBD><EFBFBD>)
* [2.1 ͨ<EFBFBD><EFBFBD>](#21-ͨ<EFBFBD><EFBFBD>)
* [2.2 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#22-<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [3. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD><EFBFBD>)
* [4. <EFBFBD><EFBFBD>д<EFBFBD>ļ<EFBFBD>ʵ<EFBFBD><EFBFBD>](#4-<2D><>д<EFBFBD>ļ<EFBFBD>ʵ<EFBFBD><CAB5>)
* [5. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#5-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [5.1 <EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ I/O](#51-<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ-io)
* [5.2 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ I/O](#52-<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ-io)
* [6. <EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>](#6-<2D>׽<EFBFBD><D7BD><EFBFBD>ʵ<EFBFBD><CAB5>)
* [6.1 ServerSocketChannel](#61-serversocketchannel)
* [6.2 Selectors](#62-selectors)
* [6.3 ?????](#63-?????)
* [6.4 ??????????](#64-??????????)
* [6.5 ???????????](#65-???????????)
* [6.6 ?????????? SelectionKey](#66-??????????-selectionkey)
* [6.7 ????? I/O](#67-?????-io)
* [?<3F><>?????](#?<3F><>?????)
* [6.3 <EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD>](#63-<EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD>)
* [6.4 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#64-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [6.5 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>µ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#65-<2D><><EFBFBD><EFBFBD><EFBFBD>µ<EFBFBD><C2B5><EFBFBD><EFBFBD><EFBFBD>)
* [6.6 ɾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SelectionKey](#66-ɾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-selectionkey)
* [6.7 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O](#67-<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-io)
* [<EFBFBD>ο<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23>ο<EFBFBD><CEBF><EFBFBD><EFBFBD><EFBFBD>)
<!-- GFM-TOC -->
# ????
# <EFBFBD><EFBFBD><EFBFBD><EFBFBD>
Java ?? I/O ???????????????
Java <EFBFBD><EFBFBD> I/O <EFBFBD><EFBFBD><EFBFBD>ſ<EFBFBD><EFBFBD>Էֳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD>
1. ?????????File
2. ????????InputStream ?? OutputStream
3. ?????????Reader ?? Writer
4. ?????????Serializable
5. ?????????Socket
6. ??????? IO??NIO
1. <EFBFBD><EFBFBD><EFBFBD>̲<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>File
2. <EFBFBD>ֽڲ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>InputStream <EFBFBD><EFBFBD> OutputStream
3. <EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Reader <EFBFBD><EFBFBD> Writer
4. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Serializable
5. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Socket
6. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ IO<EFBFBD><EFBFBD>NIO
# ???????
# <EFBFBD><EFBFBD><EFBFBD>̲<EFBFBD><EFBFBD><EFBFBD>
File ????????????????????????????????????????????????????????????
File <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD>ʾ<EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD>Ŀ¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD>ʾ<EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>
# ??????
# <EFBFBD>ֽڲ<EFBFBD><EFBFBD><EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8143787f-12eb-46ea-9bc3-c66d22d35285.jpg)
Java I/O ???????????????????? InputStream ?????InputStream ??????????FileInputStream ?? InputStream ??????????????????????????????????????FilterInputStream ????????????????????????????????????????????????? BufferedInputStream ? FileInputStream ??????????????????????<3F><>??<3F><>????????????????????? FileInputStream ????????????? BufferedInputStream ????<3F><>?
Java I/O ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>װ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģʽ<EFBFBD><EFBFBD>ʵ<EFBFBD>֡<EFBFBD><EFBFBD><EFBFBD> InputStream Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>InputStream <EFBFBD>dz<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FileInputStream <EFBFBD><EFBFBD> InputStream <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>࣬<EFBFBD><EFBFBD><EFBFBD>ھ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FilterInputStream <20><><EFBFBD>ڳ<EFBFBD><DAB3><EFBFBD>װ<EFBFBD><D7B0><EFBFBD>ߣ<EFBFBD>װ<EFBFBD><D7B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>װ<EFBFBD><D7B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD>Ĺ<EFBFBD><C4B9>ܣ<EFBFBD><DCA3><EFBFBD><EFBFBD><EFBFBD> BufferedInputStream Ϊ FileInputStream <EFBFBD>ṩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĺ<EFBFBD><EFBFBD>ܡ<EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD>湦<EFBFBD>ܵ<EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD> FileInputStream <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> BufferedInputStream <EFBFBD><EFBFBD><EFBFBD>󼴿ɡ<EFBFBD>
```java
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
```
DataInputStream ?????????????????????????????????????? int??double ??????????
DataInputStream װ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD>˶Ը<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>IJ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> int<EFBFBD><EFBFBD>double <EFBFBD>Ȼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͡<EFBFBD>
????????????<3F><>???????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```java
byte[] buf = new byte[20*1024];
int bytes = 0;
// ????? buf.length ????????????????????????????? -1 ??????????? eof???????<3F><>
// <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ buf.length <EFBFBD><EFBFBD><EFBFBD>ֽڣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ʶ<EFBFBD>ȡ<EFBFBD>ĸ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> -1 <20><>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD> eof<6F><66><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD>β
while((bytes = in.read(buf, 0 , buf.length)) != -1) {
// ...
}
```
# ???????
# <EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
???????????????<3F><>????<3F><>??<3F><>?????????????????????????? I/O ????????????????????????????????<3F><>??????????????????????????????????????<3F><>??????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǵ<EFBFBD><EFBFBD>̻<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>紫<EFBFBD>䣬<EFBFBD><EFBFBD>С<EFBFBD>Ĵ洢<EFBFBD><EFBFBD>Ԫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽڣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O <20><><EFBFBD><EFBFBD><EFBFBD>Ķ<EFBFBD><C4B6><EFBFBD><EFBFBD>ֽڶ<D6BD><DAB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڳ<EFBFBD><DAB3><EFBFBD><EFBFBD>в<EFBFBD><D0B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>в<EFBFBD><D0B2><EFBFBD><EFBFBD>ķ<EFBFBD><C4B7><EFBFBD><EFBFBD><EFBFBD>
InputStreamReader ?????????????????????????????OutputStreamWriter ??????????????????????????????????????? Reader ?? Writer??
InputStreamReader ʵ<EFBFBD>ִ<EFBFBD><EFBFBD>ı<EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>OutputStreamWriter ʵ<><CAB5><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>ı<EFBFBD><C4B1>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƕ<EFBFBD><C7B6>̳<EFBFBD><CCB3><EFBFBD> Reader <EFBFBD><EFBFBD> Writer<EFBFBD><EFBFBD>
????????????????????????????????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD>ַ<EFBFBD>ת<EFBFBD><EFBFBD>Ϊ<EFBFBD>ֽڣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϳ<EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD>
```java
byte[] bytes = str.getBytes(encoding); // ????
String str = new String(bytes, encoding)?? // ????
byte[] bytes = str.getBytes(encoding); // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>
String str = new String(bytes, encoding)<EFBFBD><EFBFBD> // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```
GBK ?????<3F><>?????? 2 ?????????? 1 ??????UTF-8 ?????<3F><>?????? 3 ?????????? 1 ??????Java ?????????? UTF-16be???????????? 2 ??????
GBK <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ 2 <20><><EFBFBD>ֽڣ<D6BD>Ӣ<EFBFBD><D3A2>ռ 1 <20><><EFBFBD>ֽڣ<D6BD>UTF-8 <20><><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD>ռ 3 <20><><EFBFBD>ֽڣ<D6BD>Ӣ<EFBFBD><D3A2>ռ 1 <20><><EFBFBD>ֽڣ<D6BD>Java ʹ<><CAB9>˫<EFBFBD>ֽڱ<D6BD><DAB1><EFBFBD> UTF-16be<62><65><EFBFBD><EFBFBD><EFBFBD>ĺ<EFBFBD>Ӣ<EFBFBD>Ķ<EFBFBD>ռ 2 <20><><EFBFBD>ֽڡ<D6BD>
????????????????<3F><>??????????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ò<EFBFBD>ͬ<EFBFBD>ı<EFBFBD><EFBFBD>뷽ʽ<EFBFBD><EFBFBD>ô<EFBFBD>ͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>롣
# ???????
# <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
???<3F><>????????????????????????<3F><>?????<3F><>?????
<EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǽ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>洢<EFBFBD>ʹ<EFBFBD><EFBFBD>䡣
???<3F><>???ObjectOutputStream.writeObject()
<EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>ObjectOutputStream.writeObject()
?????<3F><>???ObjectInputStream.readObject()
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>ObjectInputStream.readObject()
???<3F><>??????????? Serializable ?????????????????????<3F>ʦ<EFBFBD>??????????
<EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫʵ<EFBFBD><EFBFBD> Serializable <20>ӿڣ<D3BF><DAA3><EFBFBD>ֻ<EFBFBD><D6BB>һ<EFBFBD><D2BB><EFBFBD><EFBFBD>׼<EFBFBD><D7BC>û<EFBFBD><C3BB><EFBFBD>κη<CEBA><CEB7><EFBFBD><EFBFBD><EFBFBD>Ҫʵ<D2AA>֡<EFBFBD>
transient ??????????<3F><>??????????<3F><>???
transient <EFBFBD>ؼ<EFBFBD><EFBFBD>ֿ<EFBFBD><EFBFBD><EFBFBD>ʹһЩ<EFBFBD><EFBFBD><EFBFBD>Բ<EFBFBD><EFBFBD>ᱻ<EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>
**ArrayList ???<3F><>???????<3F><>??????**??ArrayList ?<3F>՛<EFBFBD>????????????? transient ???<3F><>???????????????????????????????<3F><>????????????????????<3F><>???????????<3F><>????????<3F><>???<3F><>???????<3F><>?????????????????<3F><>????????????????????????
**ArrayList <EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>**<EFBFBD><EFBFBD>ArrayList <EFBFBD>д洢<EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> transient <20><><EFBFBD>εģ<CEB5><C4A3><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƕ<EFBFBD>̬<EFBFBD><CCAC>չ<EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĿռ䶼<D5BC><E4B6BC>ʹ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD><EFBFBD>˾Ͳ<CBBE><CDB2><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD>ݶ<EFBFBD><DDB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><D0BB><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD>д<EFBFBD><D0B4><EFBFBD>л<EFBFBD><D0BB>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><DDB5>Dz<EFBFBD><C7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>
```
private transient Object[] elementData;
```
# ???????
# <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
Java ?<3F><>?????????
Java <EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֧<EFBFBD>֣<EFBFBD>
1. InetAddress????????????????????????? IP ?????
2. URL?????????<3F><>??????? URL ?????????????<3F><>??????????????
3. Sockets????? TCP <20><>?????????????
4. Datagram????? UDP <20><>?????????????
1. InetAddress<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD>ʾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD>Ӳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7>
2. URL<EFBFBD><EFBFBD>ͳһ<EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> URL <20><><EFBFBD><EFBFBD>ֱ<EFBFBD>Ӷ<EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD>ݣ<EFBFBD>
3. Sockets<EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD> TCP Э<><D0AD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD>
4. Datagram<EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD> UDP Э<><D0AD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD>
## 1. InetAddress
??<3F><>??<3F><>??????????????????????????????????? InetAddress.getByName(String host)??InetAddress.getByAddress(byte[] addr)??
û<EFBFBD>й<EFBFBD><EFBFBD>й<EFBFBD><EFBFBD>캯<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> InetAddress.getByName(String host)<EFBFBD><EFBFBD>InetAddress.getByAddress(byte[] addr)<EFBFBD><EFBFBD>
## 2. URL
???????? URL ?<3F><>???????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>Ӵ<EFBFBD> URL <20>ж<EFBFBD>ȡ<EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```java
URL url = new URL("http://www.baidu.com");
InputStream is = url.openStream(); // ?????
InputStreamReader isr = new InputStreamReader(is, "utf-8"); // ?????
InputStream is = url.openStream(); // <EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD>
InputStreamReader isr = new InputStreamReader(is, "utf-8"); // <EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD>
BufferedReader br = new BufferedReader(isr);
String line = br.readLine();
while (line != null) {
@ -137,56 +137,56 @@ is.close();
## 3. Sockets
Socket ??????
Socket ͨ<EFBFBD><EFBFBD>ģ<EFBFBD><EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/fa4101d7-19ce-4a69-a84f-20bbe64320e5.jpg)
- ServerSocket????????????
- Socket?????????
- ServerSocket<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- Socket<EFBFBD><EFBFBD><EFBFBD>ͻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
??????????????? InputStream ?? OutputStream ?????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϳͻ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> InputStream <EFBFBD><EFBFBD> OutputStream <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
## 4. Datagram
- DatagramPacket?????????
- DatagramSocket???????
- DatagramPacket<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݰ<EFBFBD><EFBFBD><EFBFBD>
- DatagramSocket<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
# NIO
NIO ???????? I/O ???? ( ??????????????? ) ?????????????? ??????????????????????????????????
NIO <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD> I/O <20><><EFBFBD><EFBFBD> ( <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ) ת<>ƻز<C6BB><D8B2><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>Աȥ<D4B1><C8A5><EFBFBD>ƾͿ<C6BE><CDBF>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶȡ<D9B6>
## 1. ?????
## 1. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
I/O ?? NIO ?????????????????????????????????????????I/O ??????????????????? NIO ???????????????
I/O <EFBFBD><EFBFBD> NIO <EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD>ᵽ<EFBFBD>ģ<EFBFBD>I/O <20><><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD> NIO <20>Կ<EFBFBD><D4BF>ķ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>
???????? I/O ???????????<3F><>????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? I/O ?????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O һ<><D2BB>һ<EFBFBD><D2BB><EFBFBD>ֽڽ<D6BD><DABD>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֽڵ<D6BD><DAB5><EFBFBD><EFBFBD>ݣ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֽڵ<D6BD><DAB5><EFBFBD><EFBFBD>ݡ<EFBFBD>Ϊ<EFBFBD><CEAA>ʽ<EFBFBD><CABD><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>dz<EFBFBD><C7B3><EFBFBD><EFBFBD>ף<EFBFBD><D7A3><EFBFBD><EFBFBD>Ӽ<EFBFBD><D3BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ա<EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD>𵥸<EFBFBD><F0B5A5B8><EFBFBD><EFBFBD>Ӵ<EFBFBD><D3B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD>֣<EFBFBD><D6A3><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD><EFBFBD>Լ򵥵ġ<F2B5A5B5><C4A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ǣ<EFBFBD><C7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O ͨ<><CDA8><EFBFBD>൱<EFBFBD><E0B5B1><EFBFBD><EFBFBD>
????????? I/O ??????????????????????????????????<3F><>??????????????????<3F><>???<3F><>????????????????????????????????? I/O ????<3F><>???????? I/O ?????<3F><>????????????
һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O ϵͳ<CFB5>Կ<EFBFBD><D4BF><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>ÿһ<C3BF><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>в<EFBFBD><D0B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ݿ顣<DDBF><E9A1A3><EFBFBD>鴦<EFBFBD><E9B4A6><EFBFBD><EFBFBD><EFBFBD>ݱȰ<DDB1><C8B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD>öࡣ<C3B6><E0A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O ȱ<><C8B1>һЩ<D2BB><D0A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O <20><><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ժͼ<D4BA><CDBC><EFBFBD><EFBFBD>ԡ<EFBFBD>
I/O ???? NIO ?????????????java.io.\* ????? NIO ????????????????????????????????? NIO ???<3F><>????????<3F><> java.io.\* ???<3F><>??<3F><>??????????????<3F><>??????????????<3F><>????????????????<3F><>??????????????
I/O <EFBFBD><EFBFBD><EFBFBD><EFBFBD> NIO <EFBFBD>Ѿ<EFBFBD><EFBFBD>ܺõؼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ˣ<EFBFBD>java.io.\* <20>Ѿ<EFBFBD><D1BE><EFBFBD> NIO Ϊ<><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD>ˣ<EFBFBD><CBA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NIO <20><>һЩ<D2BB><D0A9><EFBFBD>ԡ<EFBFBD><D4A1><EFBFBD><EFBFBD>磬 java.io.\* <20><><EFBFBD>е<EFBFBD>һЩ<D2BB><D0A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Կ<EFBFBD><D4BF><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><CABD>д<EFBFBD><D0B4><EFBFBD>ݵķ<DDB5><C4B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ü<EFBFBD>ʹ<EFBFBD>ڸ<EFBFBD><DAB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶ<EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD><EFBFBD>졣
## 2. ?????????
## 2. ͨ<EFBFBD><EFBFBD><EFBFBD>뻺<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
### 2.1 ???
### 2.1 ͨ<EFBFBD><EFBFBD>
??? Channel ???? I/O ???<3F><>??????????????????????<3F><>???????
ͨ<EFBFBD><EFBFBD> Channel <EFBFBD>Ƕ<EFBFBD>ԭ I/O <EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD>⣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>
????????????????????????????????????????(??????????? InputStream ???? OutputStream ??????)?? ???????????????????????<3F><>???????????<3F><>??
ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>IJ<EFBFBD>֮ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڣ<EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><EFBFBD><EFBFBD>(һ<><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> InputStream <EFBFBD><EFBFBD><EFBFBD><EFBFBD> OutputStream <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)<29><> <20><>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD>˫<EFBFBD><CBAB><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڶ<EFBFBD><DAB6><EFBFBD>д<EFBFBD><D0B4><EFBFBD><EFBFBD>ͬʱ<CDAC><CAB1><EFBFBD>ڶ<EFBFBD>д<EFBFBD><D0B4>
????????????????
ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD>
- FileChannel????????<EFBFBD><EFBFBD>?<EFBFBD><EFBFBD>?????
- DatagramChannel????? UDP ??<3F><>???????????
- SocketChannel????? TCP ??<3F><>???????????
- ServerSocketChannel???????????????? TCP ?????????????????????????????? SocketChannel??
- FileChannel<65><6C><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>ж<EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>
- DatagramChannel<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> UDP <20><>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>
- SocketChannel<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> TCP <20><>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>
- ServerSocketChannel<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>½<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> TCP <20><><EFBFBD>ӣ<EFBFBD><D3A3><EFBFBD>ÿһ<C3BF><D2BB><EFBFBD>½<EFBFBD><C2BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӷ<EFBFBD><D3B6>ᴴ<EFBFBD><E1B4B4>һ<EFBFBD><D2BB> SocketChannel<EFBFBD><EFBFBD>
### 2.2 ??????
### 2.2 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
????????????????<3F><>???????????????????<3F><>?????????????<3F><>?????<3F><>??????????????????<3F><>???????????????????????<EFBFBD><EFBFBD>?<EFBFBD><EFBFBD>??????????????????????
<EFBFBD><EFBFBD><EFBFBD>͸<EFBFBD>һ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD>󶼱<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷŵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD>أ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݶ<EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>Ӷ<EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ⱦ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
???????????????????<3F><>??????????????????<3F><>?????????????????????????????????????????/<2F><>?????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>顣<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD>˶<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵĽṹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ը<EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD>Ķ<EFBFBD>/д<><D0B4><EFBFBD>̡<EFBFBD>
???????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD>
- ByteBuffer
- CharBuffer
@ -197,50 +197,50 @@ I/O ???? NIO ?????????????java.io.\* ????? NIO ?????????????????????????????????
- DoubleBuffer
## 3. ????????????
## 3. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- capacity???????????
- position??????????<3F><>?????????
- limit?????????<3F><>?????????
- capacity<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- position<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- limit<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Զ<EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
??????????????
״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĸı<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD>
1\. ????????<3F><>? 8 ???????????????? position ? 0???? limit == capacity == 9??capacity ???????????????????????????
1\. <EFBFBD>½<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>СΪ 8 <20><><EFBFBD>ֽڵĻ<DAB5><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ position Ϊ 0<EFBFBD><EFBFBD><EFBFBD><EFBFBD> limit == capacity == 9<EFBFBD><EFBFBD>capacity <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ı䣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ۻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1bea398f-17a7-4f67-a90b-9e2d243eaa9a.png)
2\. ??????????<3F><>?? 3 ?????????<3F><>???????<3F><>???? position ?????? 3??limit ???????
2\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD>ȡ 3 <20><><EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD>뻺<EFBFBD><EBBBBA><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD>ʱ position <20>ƶ<EFBFBD><C6B6><EFBFBD>Ϊ 3<><33>limit <20><><EFBFBD>ֲ<EFBFBD><D6B2>䡣
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/4628274c-25b6-4053-97cf-d1239b44c43d.png)
3\. ???????????????<3F><>???????????????????? flip() ??????????????? limit ???????? position?????? position ????? 0??
3\. <EFBFBD>ڽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD>֮ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>ȵ<EFBFBD><EFBFBD><EFBFBD> flip() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> limit <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA>ǰ position<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> position <EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 0<><30>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/952e06bd-5a65-4cab-82e4-dd1536462f38.png)
4\. ?????????? 4 ??????????????<3F><>???? position ??? 4??
4\. <EFBFBD>ӻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ 4 <20><><EFBFBD>ֽڵ<D6BD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD>ʱ position <EFBFBD><EFBFBD>Ϊ 4<><34>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/b5bdcbe2-b958-4aef-9151-6ad963cb28b4.png)
5\. ?????????? clear() ??????????????????? position ?? limit ????????????<3F><>?<3F><>?
5\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> clear() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ<EFBFBD><D5BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ position <EFBFBD><EFBFBD> limit <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD>á<EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/67bf5487-c45d-49b6-b9c0-a058d8c68902.png)
## 4. ??<3F><>??????
## 4. <EFBFBD><EFBFBD>д<EFBFBD>ļ<EFBFBD>ʵ<EFBFBD><EFBFBD>
1\. ?????????????? FileInputStream???????? FileInputStream ??????? FileChannel??
1\. ΪҪ<EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileInputStream<EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> FileInputStream <EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileChannel<EFBFBD><EFBFBD>
```java
FileInputStream fin = new FileInputStream("readandshow.txt");
FileChannel fic = fin.getChannel();
```
2\. ???????????? 1024 ?? Buffer
2\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 1024 <EFBFBD><EFBFBD> Buffer
```java
ByteBuffer buffer = ByteBuffer.allocate(1024);
```
3\. ??????????? FileChannel <EFBFBD><EFBFBD>?? Buffer ?<3F><>??????????????? read() ???????? -1
3\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileChannel д<EFBFBD>뵽 Buffer <EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵĻ<EFBFBD><EFBFBD><EFBFBD> read() <20><><EFBFBD><EFBFBD><EFBFBD>᷵<EFBFBD><E1B7B5> -1
```java
int r = fcin.read(buffer);
@ -249,86 +249,86 @@ if (r == -1) {
}
```
4\. ??<3F><>?????????? FileOutputStream???????? FileOutputStream ?????? FileChannel
4\. ΪҪд<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileOutputStream<EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> FileOutputStream <EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileChannel
```java
FileOutputStream fout = new FileOutputStream("writesomebytes.txt");
FileChannel foc = fout.getChannel();
```
5\. ???? flip() ?<3F><>???<EFBFBD><EFBFBD>
5\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD> flip() <EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>д
```java
buffer.flip();
```
6\. ?? Buffer ?<3F><>???????????? FileChannel ??
6\. <EFBFBD><EFBFBD> Buffer <EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݶ<EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> FileChannel <EFBFBD><EFBFBD>
```java
foc.write(buffer);
```
7\. ?????? clear() ?????????
7\. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> clear() <EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```java
buffer.clear();
```
## 5. ???????????
## 5. <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
??????FileChannel ?????<3F><>?????????????????? Channel ?????
Ӧ<EFBFBD><EFBFBD>ע<EFBFBD>⣬FileChannel <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģʽ<EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD> Channel <EFBFBD><EFBFBD><EFBFBD>ԡ<EFBFBD>
### 5.1 ????? I/O
### 5.1 <EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ I/O
????? I/O ????? InputStream.read() ?????????????????????????????????????? ServerSocket.accept() ???????????????????<3F><>??????????????????????????????????????????????????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ I/O <20>ڵ<EFBFBD><DAB5><EFBFBD> InputStream.read() <EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>һֱ<EFBFBD>ȵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>Ż᷵<EFBFBD>أ<EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD><EFBFBD> ServerSocket.accept() <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>Ҳ<EFBFBD><D2B2>һֱ<D2BB><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>пͻ<D0BF><CDBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӲŻ᷵<C5BB>أ<EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD>ͻ<EFBFBD><CDBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӹ<EFBFBD><D3B9><EFBFBD><EFBFBD>󣬷<EFBFBD><F3A3ACB7><EFBFBD><EFBFBD>˶<EFBFBD><CBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>߳<EFBFBD>ȥ<EFBFBD><C8A5><EFBFBD><EFBFBD><EFBFBD>ÿͻ<C3BF><CDBB>˵<EFBFBD><CBB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/edc23f99-c46c-4200-b64e-07516828720d.jpg)
### 5.2 ??????? I/O
### 5.2 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ I/O
?????????????????????<3F><>? I/O ???????????????
<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ר<EFBFBD>ŵ<EFBFBD><EFBFBD>߳<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD> I/O <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD>
??????????????????????????????????????????????
<EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>򴥷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD>
???????????????? wait()??notify() ?????????????????????<3F><>???????????????????<3F><>??????<3F><>???
<EFBFBD>߳<EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><EFBFBD>߳<EFBFBD>֮<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD> wait()<EFBFBD><EFBFBD>notify() <EFBFBD>ȷ<EFBFBD>ʽͨ<EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD>֤ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ν<EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>
![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/7fcb2fb0-2cd9-4396-bc2d-282becf963c3.jpg)
## 6. ????????
## 6. <EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>
### 6.1 ServerSocketChannel
???????????????? ServerSocketChannel ?????????????
ÿһ<EFBFBD><EFBFBD><EFBFBD>˿ڶ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> ServerSocketChannel <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD>
```java
ServerSocketChannel ssc = ServerSocketChannel.open();
ssc.configureBlocking(false); // ???????????
ssc.configureBlocking(false); // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
ServerSocket ss = ssc.socket();
InetSocketAddress address = new InetSocketAddress(ports[i]);
ss.bind(address); // ?????
ss.bind(address); // <EFBFBD>󶨶˿ں<EFBFBD>
```
### 6.2 Selectors
?? I/O ??? Selector ??????? I/O ???????? ?D ?????????????????????????????????????????????????????????
<EFBFBD>첽 I/O ͨ<EFBFBD><EFBFBD> Selector ע<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ض<EFBFBD> I/O <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD>Ȥ <20>D <20>ɶ<EFBFBD><C9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵĵ<DDB5><C4B5><EFBFBD>µ<EFBFBD><C2B5>׽<EFBFBD><D7BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵȵȣ<C8B5><C8A3>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD>ʱ<EFBFBD><CAB1>ϵͳ<CFB5><CDB3><EFBFBD>ᷢ<EFBFBD><E1B7A2>֪ͨ<CDA8><D6AA>
???? Selectors ?????????????????????? register() ??????register() ????????????????? Selector????????????? OP_ACCEPT?????????????????????? accept ????????????????????????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD> Selectors ֮<EFBFBD>󣬾Ϳ<EFBFBD><EFBFBD>ԶԲ<EFBFBD>ͬ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> register() <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>register() <EFBFBD>ĵ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Selector<6F><72><EFBFBD>ڶ<EFBFBD><DAB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OP_ACCEPT<50><54><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD> accept <20>¼<EFBFBD><C2BC><EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>µ<EFBFBD><C2B5><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD>
SelectionKey ????????????? Selector ?????????????? Selector ????????????????????????????????????? SelectionKey ?????<3F><>??SelectionKey ?????????????????????
SelectionKey <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD> Selector <20>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD><EFBFBD>ע<EFBFBD>ᡣ<EFBFBD><E1A1A3>ij<EFBFBD><C4B3> Selector ֪ͨ<CDA8><D6AA>ij<EFBFBD><C4B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD>ṩ<EFBFBD><E1B9A9>Ӧ<EFBFBD>ڸ<EFBFBD><DAB8>¼<EFBFBD><C2BC><EFBFBD> SelectionKey <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еġ<EFBFBD>SelectionKey <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ע<EFBFBD>ᡣ
```java
Selector selector = Selector.open();
SelectionKey key = ssc.register(selector, SelectionKey.OP_ACCEPT);
```
### 6.3 ?????
### 6.3 <EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD>
???????????? Selector ?? select() ??????????????????????????????????????????????????????????????????????? select() ?????????????????????????????
<EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD> Selector <EFBFBD><EFBFBD> select() <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ע<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߸<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD> select() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
??????????????? Selector ?? selectedKeys() ?????????????????????? SelectionKey ???????? ???? ??
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD> Selector <EFBFBD><EFBFBD> selectedKeys() <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ط<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD> SelectionKey <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB> <20><><EFBFBD><EFBFBD> <20><>
??????????? SelectionKeys ?????<3F><>?????? SelectionKey ??????????????????? SelectionKey????????????????????? I/O ???????????????????<3F><> I/O ????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SelectionKeys <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δ<EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD> SelectionKey <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿһ<EFBFBD><EFBFBD> SelectionKey<65><79><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʲô I/O <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD>Ӱ<EFBFBD><D3B0><EFBFBD><EFBFBD>Щ I/O <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```java
int num = selector.select();
@ -342,9 +342,9 @@ while (it.hasNext()) {
}
```
### 6.4 ??????????
### 6.4 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
??????<3F><>??????????????? ServerSocketChannel??????????????????????????????????????? SelectionKey ???? readyOps() ??????????<3F><>????????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǽ<EFBFBD>ע<EFBFBD><EFBFBD><EFBFBD><EFBFBD> ServerSocketChannel<65><6C><EFBFBD><EFBFBD><EFBFBD>ҽ<EFBFBD>ע<EFBFBD><D7A2><EFBFBD><EFBFBD><EFBFBD>ǡ<EFBFBD><C7A1><EFBFBD><EFBFBD>ա<EFBFBD><D5A1>¼<EFBFBD><C2BC><EFBFBD>Ϊȷ<CEAA><C8B7><EFBFBD><EFBFBD>һ<EFBFBD>㣬<EFBFBD><E3A3AC><EFBFBD>Ƕ<EFBFBD> SelectionKey <EFBFBD><EFBFBD><EFBFBD><EFBFBD> readyOps() <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>鷢<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʲô<EFBFBD><EFBFBD><EFBFBD>͵<EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD><EFBFBD>
```java
if ((key.readyOps() & SelectionKey.OP_ACCEPT)
@ -354,39 +354,39 @@ if ((key.readyOps() & SelectionKey.OP_ACCEPT)
}
```
??????????? readOps() ??????????????????????????
<EFBFBD><EFBFBD><EFBFBD>Կ϶<EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD> readOps() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǹ<EFBFBD><C7B8>¼<EFBFBD><C2BC><EFBFBD><EFBFBD>µ<EFBFBD><C2B5><EFBFBD><EFBFBD>ӡ<EFBFBD>
### 6.5 ???????????
### 6.5 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>µ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
?????????????????????????????????????????????????????????????????????????????? accept() ????????????
<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>֪<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵȴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Կ<EFBFBD><EFBFBD>԰<EFBFBD>ȫ<EFBFBD>ؽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD> accept() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
```java
ServerSocketChannel ssc = (ServerSocketChannel)key.channel();
SocketChannel sc = ssc.accept();
```
??????????????? SocketChannel ??????????????????????????????????????????????????????????????????????? SocketChannel ??? Selector????????????
<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ǽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD> SocketChannel <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ġ<EFBFBD><C4A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڽ<EFBFBD><DABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD>Ϊ<EFBFBD>˶<EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><D7BD>ֵ<EFBFBD><D6B5><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǻ<EFBFBD><C7BB><EFBFBD><EFBFBD>뽫 SocketChannel ע<EFBFBD>ᵽ Selector<EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><EFBFBD>
```java
sc.configureBlocking( false );
SelectionKey newKey = sc.register( selector, SelectionKey.OP_READ );
```
?????????? register() ?? OP_READ ???????? SocketChannel ??????? ??? ?????? ???? ???????
ע<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD> register() <EFBFBD><EFBFBD> OP_READ <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SocketChannel ע<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>ȡ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD>
### 6.6 ?????????? SelectionKey
### 6.6 ɾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SelectionKey
????? SelectionKey ???????????????????????????????????????????????? SelectionKey ????????????????????????????????????????????????????????????????????????????????????????????<3F><>????????????????????? remove() ???????????????? SelectionKey??
<EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD> SelectionKey ֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Է<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD><EFBFBD>ˡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>DZ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SelectionKey <20><>ѡ<EFBFBD><D1A1><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɾ<EFBFBD><C9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB>ɾ<EFBFBD><C9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><C3B4><EFBFBD><EFBFBD>Ȼ<EFBFBD><C8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD>֣<EFBFBD><D6A3><EFBFBD><EFBFBD>ᵼ<EFBFBD><E1B5BC><EFBFBD><EFBFBD><EFBFBD>dz<EFBFBD><C7B3><EFBFBD><EFBFBD>ٴδ<D9B4><CEB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><C7B5>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> remove() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɾ<EFBFBD><C9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SelectionKey<EFBFBD><EFBFBD>
```java
it.remove();
```
???????????????????????????????????<3F><>????????(???????????? I/O ???)???
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǿ<EFBFBD><EFBFBD>Է<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܴ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>(<28><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O <20>¼<EFBFBD>)<29>ˡ<EFBFBD>
### 6.7 ????? I/O
### 6.7 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O
?????????????????????????????????? I/O ??????????????????<3F><>??? Selector.select()????????????????? I/O ?????????<3F><>? SelectionKey ???????? OP_READ ??????????????
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ᴥ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> I/O <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ᵼ<EFBFBD><E1B5BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD><EFBFBD>е<EFBFBD><D0B5><EFBFBD> Selector.select()<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>߶<EFBFBD><DFB6><EFBFBD> I/O <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>Σ<EFBFBD> SelectionKey <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ OP_READ <20>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE>
```java
} else if ((key.readyOps() & SelectionKey.OP_READ)
@ -398,9 +398,9 @@ it.remove();
```
# ?<3F><>?????
# <EFBFBD>ο<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- Eckel B, ????? , ??? , ?? . Java ?????? [M]. ??<3F><>????????? , 2002.
- [IBM: NIO ????](https://www.ibm.com/developerworks/cn/education/java/j-nio/j-nio.html)
- [ ??????? Java I/O ????????? ](https://www.ibm.com/developerworks/cn/java/j-lo-javaio/index.html)
- [NIO ??? IO ?????? ](http://blog.csdn.net/shimiso/article/details/24990499)
- Eckel B, <EFBFBD><EFBFBD><EFBFBD>˶<EFBFBD> , <20><><EFBFBD><EFBFBD> , <EFBFBD><EFBFBD> . Java <EFBFBD><EFBFBD><EFBFBD><EFBFBD>˼<EFBFBD><EFBFBD> [M]. <20><>е<EFBFBD><D0B5>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> , 2002.
- [IBM: NIO <EFBFBD><EFBFBD><EFBFBD><EFBFBD>](https://www.ibm.com/developerworks/cn/education/java/j-nio/j-nio.html)
- [ <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Java I/O <EFBFBD>Ĺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ](https://www.ibm.com/developerworks/cn/java/j-lo-javaio/index.html)
- [NIO <EFBFBD>봫ͳ IO <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ](http://blog.csdn.net/shimiso/article/details/24990499)