Preliminary discussion on Java I/O working mechanism

From a book: Deep inside Java Web technology

Basic architecture of the 1.Java I/O class Library

Java I/O operations class in the package java.io, about nearly 80 classes, probably divided into the following 4 groups:

• Byte-based operation of I/O interfaces: InputStream and OutputStream
• I/O interfaces based on character manipulation: writer and reader
• Disk operation-based I/O interface: File
• Network operation-based I/O interface: Socket

The first two groups are mainly data transmission data format, the latter two groups are mainly the way to transfer data.

1.1 Byte-based operation of I/O interfaces InputStream and OutputStream

InputStream Interface Common methods:

int read ();

int available ();

int Read (byte[] b);

int read (byte[] b,int off,int L);

OutputStream Interface Common methods:

Close ();

Flush ();

Writer (byte[] b);

Writer (byte[] b,int off,int L);

1.2 Interface for character-based I/O operations: Writer and reader.

The minimum storage unit for I/O operations is bytes, but because of the characters that are commonly manipulated in our programs, I/O methods for manipulating characters are provided.

Writer interface Common methods:

Writer (byte[] b);

Writer (byte[] b,int setoff,int L);

Writer (String S,int setoff,int L);

writer (int i);

Flush ();

Close ();

Reader interface Common methods:

int read ();

int read (byte[] b);

int read (byte[] b,int setoff,int L);

void Close ();

1.3 byte-to-character conversion interface

Data persistence or network transmission is done in bytes, so you know how to convert between bytes and characters.

　

InputStreamReader class

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Preliminary discussion on Java I/O working mechanism