reader and writer problem

Java implementations:The key to this problem is the synchronization between reader and writer, especially the use of Java to operate.1. Wait for the reader, use Countdownlatch mreaderlatch, but Countdownlatch can only be used once, so you need to new one each time.Or you might consider using semaphore instead, but Sema

FileInputStream (file);3. Create the destination document;File1 = new File ("e:\\picture2.jpg");4. Build the output stream pipelineOS = new FileOutputStream (file1);int b = 0;Reads a byte from the source file every time, as if the destination file writes a bytewhile ((B=is.read ())!=-1) {Os.write (b);}} catch (FileNotFoundException e) {TODO auto-generated Catch blockE.printstacktrace ();} catch (IOException e) {TODO auto-generated Catch blockE.printstacktrace ();}finally{try {if (os!=null) {Os.

Method Summary FileReader (File file)Creates a new filereader given the File from which the data is read. FileReader (FileDescriptor FD)Creates a new filereader given the filedescriptor from which the data is read. FileReader (String fileName)Creates a new FileReader given the file name from which the data is read. WriterWriter's subclass:It is obvious that writer is corresponding to

Stream is for byte [] operations and binary file operations. Reader and writer are used for char operations and text file operations. By default, the native encoding method is used to write char, such as UTF-8 and UTF-16 and gb2312 encoding.Reader and writer are abstract classes and cannot be used directly. Generally, filereader and filewriter are used.If the c

Readers first: Reader Process Execution: No other reader to write, direct execution There are written and so on, but other readers are reading and reading directly There are written by the writer, waiting Writer Process Execution: No other

{ Public StaticFile File =NewFILE (); Public Static void Main(string[] args) {System.out.println ("Hello world!"); Executorservice executors = Executors.newfixedthreadpool (5); Executors.execute (NewWriterr ()); Executors.execute (NewReaderr (1)); Executors.execute (NewReaderr (2)); Executors.execute (NewReaderr (3)); Executors.execute (NewReaderr (4)); Executors.shutdown (); }StaticClass Writerr implements Runnable { Public void Run(){ while(true) {file.write (); } } }StaticCl

When writing multithreading, there is a situation that is more common. That is, there are fewer opportunities for public data modification . Rather than rewrite, they read more opportunities. Reader-writer mode: Three relationships, two types of people, one placeThree types of relationships:Readers and readers: no relationshipWritten and written by: mutual exclusionReader and

ExtJs4 (9) reader and writer Ext. data. reader. Json JSON Reader uses a proxy to read the return value in JSON format returned by the server. It is generally used to load the result into a storage set. For example, we will create the following: Ext.define('User', { extend: 'Ext.data.Model', fields: ['id', 'nam

.4.CharArrayWriterpublic class Chararraywriter extends WriterOK, this class and Bytearrayoutputstream function is very similar, mainly used to write text to the built-in char[], the buff can be automatically grown. Then there are tochararray,tostring and other functions. There are WriteTo methods , you can write the data in the buff to another Witer object.5.FilterWriterPublic abstract class Filterwriter extends WriterFirst notice that this is an abstract class, it is also a decoration class, fo

() ;}}reader class and writer class Reader and writer are abstract base classes for all character stream classes that simplify the input-output programming of strings, which is used to read and write text data. The difference between a binary file and a text file. Strictly speaking, each file in the f

Reprint please indicate source: http://www.cnblogs.com/lighten/p/7071733.html1. PrefaceThe previous section has already introduced the byte stream in the IO package of Java8. This chapter begins with the introduction of another important system in Java IO, the character stream. The byte is to the computer to see, the character characters is the person to be able to realize, can imagine the character stream importance. The root of the character stream system is the abstraction of the parent

methods may write different byte sequences. The specific output depends on the encoding method,All child classes of the writer class have constructors of the specified character set.. Writer canBufferIt is possible to chain directly to bufferedwriter or indirectly (because the underlying output stream is buffered ). To force a write request to be submitted to the output media, call the flush () method: w

/** Reader Writer Questions ***/classBuffer{ publicstringbuffer[]=newstring[10];//used to identify a shared buffer The publicbooleanflag=false;//is used to identify the state of the buffer public inti=0;//represents the position written to the buffer }classwriterimplementsrunnable// There may be multiple read {privatebufferbuffer;public writer (Bufferbuffer) { t

Writer/****/ PackageCom.java.demo;ImportJava.io.File;ImportJava.io.FileWriter;ImportJava.io.Writer; Public classTestdemo { Public Static voidMain (String args[])throwsexception{//Set File pathFile FL =NewFile ("E:" +file.separator+ "Hello" + file.separator+ "demo" +file.separator+ "Java.txt" ); if(!fl.getparentfile (). exists ()) {//Parent Directory does not existFl.getparentfile (). Mkdirs ();//Create a parent directory, but do not create a f

W_lock (myLock); -STD::stringThreadId = boost::lexical_caststring>(boost::this_thread::get_id ()); inStd::cout "upgraded writer holding lock, ThreadID"" "Std::endl; theSleep ( +); theStd::cout "END, ThreadID"" "Std::endl; About the }; the the + voidReader_thread () { - readlock R_lock (myLock); theSTD::stringThreadId = boost::lexical_caststring>(boost::this_thread::get_id ());BayiStd::cout "Reader holdi

directly to n bytes, returns the number of characters actually skipped. subclasses must implement only read (char[], int, int) and close ().However, most subclasses will override some of the methods defined here to provide higher efficiency and/or other functionality. WriterThe output character Stream reader defines a method for writing data in characters. The basic methods are:void Write (int c) method: Writes a character C to the output stream. v

What is the difference between a character and a byte ...... I don't know.1. Basic operation instance import java.io.*;public class CharDemo{public static void main(String[] args){File f=new File("F:\\workspace\\Javaprj\\test.txt");Writer out=null;Reader in=null;try{out=new FileWriter(f);String str="Hello World!!!";out.write(str);System.out.println("The string "+"\"Hello World!!!\""+" has been written into

J2SE quick advanced -- four basic abstract classes of IO stream: InputStream, OutputStream, Reader, Writer, and abstract class The above section briefly describes the four abstract classes in the java. io package and Their Relationships. Here we will further summarize them and their subclasses. At the end of the previous blog, I posted the entire IO family in Java, and then I modified it again. On the basi

#include #include#includeintbuffer[Ten];inti,j;pthread_rwlock_t Rwlock;void*writefun (void*Arg) { intPID =pthread_self (); printf ("writer%d enters the waiting state .... \ n", PID); Pthread_rwlock_wrlock (Rwlock); printf ("written by%d write >>>\n", PID); Sleep (Ten); printf ("written by%d write end \ n", PID); Pthread_rwlock_unlock (Rwlock); returnNULL;}void*readfun (void*Arg) { intPID =pthread_self (); printf ("

:ImportJava.io.*;classcopytext{ Public Static voidMain (string[] args)throwsIOException {FileReader fr=NewFileReader ("F:\\myfile\\practice.txt"); FileWriter FW=NewFileWriter ("F:\\myfile\\test.txt",true); //The first way: (after all the data is read into the buffer, and then one time to continue to write to the target file) intNum=0; Char[] buf =New Char[1024]; while(num = Fr.read (buf))!=-1) {String str=NewString (buf,0, num); Fw.write ("\ r \ n" +str); //Fw.write (buf,0,num);Fw.close