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1. Store the data in the collection into a text file case:Requirement: To store string data in the ArrayList collection into a text file?(1) Analysis:Through the meaning of the topic, we can know some of the following things,A string is stored in the ArrayList collection.Traverse the ArrayList collection to get the data.It is then stored in a text file.The text file description uses a character stream .(2)Data Source :ArraylistDestination :A.txt--FileWriter--BufferedWriter2. code example:1 Pack

);Wuyi } the } - Private Static voidCopyFile (file srcfile, file newFile)throwsIOException { WuBufferedinputstream bis =NewBufferedinputstream (NewFileInputStream ( - srcfile)); AboutBufferedoutputstream BOS =NewBufferedoutputstream ( $ NewFileOutputStream (NewFile)); - byte[] Bys =New byte[1024]; - intLen = 0; - while(len = Bis.read (bys))! =-1) { ABos.write (bys, 0, Len); + } the bos.close (); - bis.close (); $ } the}Java Bas

1. Randomly get name cases in a text fileRequirements: I have a text file stored in a few names, please write a program implementation randomly get a person's name.Analysis:A: Storing the data in a text file in a collectionB: Randomly produce an indexC: Gets a value based on the index2. Code implementation:1 Packagecn.itcast_02;2 3 ImportJava.io.BufferedReader;4 ImportJava.io.FileReader;5 Importjava.io.IOException;6 Importjava.util.ArrayList;7 ImportJava.util.Random;8 9 /*Ten * Requirements: I

Goal:1, master the three kinds of system support for IO:System.outSystem.inSystem.err2, master the difference between System.out and System.err.3, master input, output redirect.Constants of the System classJava has some support for the system class for IO, and three constants are prefabricated.PrintStream Out,printstream Err,inputstream in.Variables declared with static final are global constants, and all word letters must be capitalized if they are c

can be divided into which two, respectively, to illustrate1 "input and output relative to program2 "input stream InputStream3 "Output stream OutputStream===============================================================4. According to the implementation of the function is divided into which two, respectively, illustrate1 in accordance with the implementation of the function is divided into "node flow" "Processing flow"2 "node stream: OutputStream3 "Processing flow: OutputStreamWriter==============

Question: I am studying windows SDK programming recently. I plan to share my learning summary and experiences with you, for more information, see Asynchronous Io is an essential feature of modern operating systems. It makes valuable CPU computing resources not wasted waiting for slow Io. Its behavior is intuitive. after sending an IO request, the user thread do

each block device or partition of a block device has its own request queue (request_queue), and each request queue can select an I/O Scheduler to coordinate the request submitted . The basic purpose of the I/O Scheduler is to arrange requests according to the sector code they correspond to on the block device to reduce the movement of the heads and improve efficiency. Requests in the request queue for each device are responded to in order. In fact, in addition to this queue, each scheduler itse

each block device or partition of a block device has its own request queue (request_queue), and each request queue can select an I/O Scheduler to coordinate the request submitted . The basic purpose of the I/O Scheduler is to arrange requests according to the sector code they correspond to on the block device to reduce the movement of the heads and improve efficiency. Requests in the request queue for each device are responded to in order. In fact, in addition to this queue, each scheduler itse

Channels are used in concert with the buffer in NIO. A channel is a bidirectional channel that is readable and writable. It is a bit similar to stream, but stream is unidirectional, the application does not directly perform read/write operations on the channel, but must use the buffer. For example, when reading a channel, you must first read the data into the corresponding buffer and then read it in the buffer. An example of using filechannel Package NiO; import Java.

A. Almost every peripheral is done by reading and writing registers on the device. Peripheral registers are also known as "I/O ports, usually includes: control registers, State registers and data registers three categories, and a peripheral register is usually continuously address. There are two ways for the CPU to address the physical addresses of peripheral IO ports: One is I/O mapping (i/o-mapped) and the other is the memory-mapped method (memory-m

Java (java io-File class), io-1. In the entire io package, the only class that indicates the File itself is the File class. You can use the File class to create or delete files. To use the File class, first observe the construction method of the File class. The common construction methods of this class are as follows: public File (String pathname)-> when instanti

Management of I/O Ports and I/O memory in Linux Port is the address of the register that can be directly accessed by the CPU in the interface circuit. Almost every type of peripherals is performed by reading and writing registers on the device. The CPU sends commands to registers in the interface circuit through these addresses to read the status and transmit data. A peripheral register, also known as an "I/O port", usually includes three categories: control registers, status registers, and data

Label:evaluating storage devices from a databaseIOPerformance ---------oracle11g IO Calibration Function Introduction Preface I/OSubsystem isORACLEan important part of the database becauseI/Ooperation is through the whole process of database management, its operations include logs, tables, indexes, data dictionaries, and some sort,undooperations and so on, each database reads or writes data on disk, resulting in a diskIO, so to speak of a normal busin

In the process of writing the driver program, it is seldom noticed thatIO portAndIo mem. Although some non-conforming code can achieve the ultimate goal, this is extremely not recommended. 1.CPUYesI386Architecture InI386In series processing, memory and externalIoIt is an independent addressing.MemThe memory space of is32Bit can be addressable4G,IoSpace is16Bit can be addressable64 K. InLinuxIn the kernel, accessIO portMust PassIO port. AccessIo memIt's cool, externalMemIt cannot be accessed in

http://elf8848.iteye.com/category/281637Objective:In general operations work often encounter such a scenario, the server's IO load is very high (util in iostat), but unable to quickly locate the IO load source process and source files resulting in the inability to make the appropriate policy to solve the problem.This phenomenon is more common on MySQL, and before 5.6 (Performance_schema provides

Java IO learning notes (3) Conversion stream, data stream, byte array stream, and io learning notes Conversion stream1. Conversion stream: Convert byte streams to a bytes stream. After conversion, you can write content to the program with one character and one character. You can also call the write (String s) method of the character node stream, you can also apply BufferedReader () and BufferedWriter outsid

Nonblocking Io) In non-blocking modeaccept()Andread()During the operation, if the data in the kernel is not ready, it does not block the user process, but immediately returns a message. That is to say, after a read operation is initiated by a process, it does not need to block the wait all the time, but immediately gets a result.If the data is ready, the data can be read and copied to the user memory. If the result shows that the data is not ready, th

I. Synchronous blocking IO bio is a blocking IO, network communication for multi-client connection, the server is always consistent with the number of client threads to handle each client task, that is, the number of clients and threads 1:1, and read and write operations in the room block, when you have thousands of clients to connect, Causes the server to constantly establish new threads, resulting in low-

use the bindiocompletioncallback function to deliver an asynchronous Io operation. On the IO completion port, the callback function is also executed by the thread pool thread.When the queueuserworkitem function or bindiocompletioncallback function is called for the first time, the thread pool is automatically created, or when timer-queue timers or registered wait operations are placed in the callback funct

IO multi-channel model -- select, IO model -- select1. Trigger of IO multiplexing Model First, we will introduce the concept of "Trigger" in an I/O multi-channel model: 1 # There are two modes of horizontal triggering and edge triggering in linux I/O multiplexing: 2 #3 # horizontal triggering: if the file descriptor is ready for non-blocking