I. Io and stream
Data input and output (I/O for input/output)The input and output of standard input devices and standard output devices are referred to as standard I/OThe input and output of files stored on an external disk are referred to as files I/O.The input and output of the specified string bucket in the memory are referred to as string I/O.
The process of data input and output can be visually viewed as a stream.The operation for retrieving dat
java.io uses design patterns such as adapter pattern decoration mode to solve the socket and input-output problems of character streams.
A byte stream can only be processed at a time, in order to more easily manipulate the data, it adds a socket flow.
Problem Introduction:
Why is the buffer stream more efficient than ordinary file-byte throttling?
An operation without buffering, which writes a byte ever
1: Login Register IO version case (master)Ask, write it over again.Cn.itcast.pojo UserCn.itcast.dao UserdaoCn.itcast.dao.impl UserDaoImp1 (realize I don't care)Cn.itcast.game GuessnumberCn.itcast.test Usertest2: Data manipulation flow (flow of manipulating basic type data) (understanding)(1) Basic types of data can be manipulated(2) Stream object nameDataInputStreamDataOutputStream3: Memory operation flow (understanding)(1) Sometimes we do not need to
The content of this article:
What is a stream
BYTE stream
Character Stream
Starting Date: 2018-07-24
what is a stream
Flow is an abstract concept, is an abstraction of input, the input stream can be regarded as an input channel, the outpu
Elementary stream
In the MPEG-2, bit streams that contain encoded images, sounds, or data are called the basic stream ES (elementary stream ), it only contains one type of data (audio, video, or subtitle). What we call "audio", "video", or "bit stream" is elementary stream,
The IP datagram has a header and data two parts, the first part of the header is a fixed length of 20 bytes, is all the IP datagram must have. The header includes: total length, logo, MF, DF, offset.
The digital signal actually transmits the data stream, the general data flow includes the following three kinds:
ES streams: Also called basic streams, which contain continuous streams of video, audio, or data.
PES st
Java input/output streamPre-knowledge preparation1. Basic Java SyntaxBasic principle:While the program is running, it may be necessary to read the required data from an external storage medium or other program, which requires the use of an input stream object. The input stream points to the source called it, and the program reads the source data from the input stream
java.io uses design patterns such as adapter mode decoration mode to solve the problem of socket and input and output of character streams.The byte stream can only process one bytes at a time, and in order to manipulate data more conveniently, it joins the socket stream.Problem Introduction: Why is buffered stream more efficient than normal file-byte throttling?Without buffering, a byte is written for each
Java I/O article 2 (buffer stream random stream array Stream Data Stream), java Article 2
1: Buffer stream BufferedReader BufferedWriter
Strong read/write capability, able to read and write a single row of data separately, can reduce the number of visits to the hard disk.
1/
Java operation files are processed by streams (in many other languages)First: Java IO stream, divided into: input stream and output stream (this is nonsense, this is from the point of view of the flow)Second: All IO streams in Java are divided into: byte stream and character stream
File stream and data stream, file stream data stream
1. File Type
1.1,In Qt, file types are dividedTwo categories
1.1.1,Text file:The file content is a readable text character
1.1.2,Data file:The file content is binary data directly.
1.2,QFileDirectly supporting text files and data filesRead/write
. Cpp File
# Incl
Document directory
Main methods and constants in the file class
Procedure
Byte output stream: outputstream
Byte input stream: inputstream
Character output stream: writer
Character input stream: Reader
File class
In the entire Io package, the only class that indicates the file itself is the file class. You can
Java IO stream byte stream, java IO stream byteI. Common file Operations
File file = new File ("E: \ test \ javaIo"); System. out. println (file. isDirectory (); // determines whether the file is a directory (if the file does not exist, false is returned) System. out. println (file. isFile (); // determines whether the file is a specific file System. out. printl
The Java stream is processed into a character stream and a byte stream. A character stream processes a cell that is 2-byte Unicode characters, manipulating characters, character arrays, or strings, and a byte-stream processing unit of 1 bytes, manipulating bytes and byte arr
The operation of the byte stream and the character stream is basically the same, the difference is only the data unit of the operation is different: the data unit of the byte stream operation is the data unit character of bytes, character stream manipulation.InputStream and reader are the base classes for all input str
Difference between Java byte stream and hidden stream, java byte hidden stream
The use of byte streams is very similar to that of byte streams. Are there other differences between the two in addition to the differences in the operation code?In fact, the byte stream itself does not use a buffer (memory) during operation
The operation of the byte stream and the character stream is basically the same, the difference is only the data unit of the operation is different: the data unit of the byte stream operation is the data unit character of bytes, character stream manipulation.
InputStream and reader are the base classes for all input st
; System.out.println (v); Method Stringpropertynames, stores the keys in the collection to the set collection, similar to the method of the map interface keyset set2, read the key value in the file to save to the collection/* * Properties Collection Unique method load * Load (InputStream in) * Load (reader r) * Pass any byte or character input stream * Stream object read key value pair in file, sav
One, file streamThe FileStream class is primarily used to read and write disk files . Often used to store data or read configuration files to disk.Read file://File stream: Read FileStream FileStream = File.Open (@ "D:\test.txt", FileMode.Open); Initialize file stream byte[] array = new byte[filestream.length]; Initializes a byte array that is used to stage the read to byte filestream.read (array, 0, array
Java processing files in the class, stream at the end of the use of byte stream, reader and writer End is a character stream. The difference between the two is read and write, one is read by Byte, and the other is by character.
The bottom of the character stream is the byte stream
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