Java Multithreading write the same file implementation __java

Recently, the project needs to crawl a lot of data from the site, using multithreading technology, each thread crawl data need to be saved to a file, avoid consuming a lot of memory.

Idea: Multiple access threads will save the data that needs to be written to a file into a queue, and then write the data from the queue and write it to the file by a dedicated writing thread.

Writerqueue.java store data queues to output

Package com.yulore.write;
Import java.util.LinkedList;
Import java.util.concurrent.locks.Condition;
Import Java.util.concurrent.locks.Lock;

Import Java.util.concurrent.locks.ReentrantLock;
	public class Writerqueue {private static final int max_queue_size = 5000;
	Private linkedlist<string> queue = new linkedlist<string> ();
	Private lock lock = new Reentrantlock ();
	Private Condition Notfull = Lock.newcondition ();
	
	Private Condition Notempty = Lock.newcondition ();
	
	private static Writerqueue manager = new Writerqueue ();
	Private Writerqueue () {} public static Writerqueue Getqueue () {return manager;
		
		public void put (String phone) {lock.lock ();
				try {while (queue.size () = = Max_queue_size) {System.out.println ("Warning:data queue is full!");
			Notfull.await ();
			
			Queue.addfirst (phone);
		Notempty.signal ();
		catch (Interruptedexception e) {e.printstacktrace ();
		} finally{Lock.unlock (); }} public LinkedliSt<string> Takeall () {linkedlist<string> retVal = new linkedlist<string> ();
		
		Lock.lock ();
				try {while (queue.size () = = 0) {System.out.println ("Warning:data queue is empty!");
			Notempty.await ();
} retval.addall (queue);
			
			for (String str:queue) {//Retval.add (str);//}//Empty queue queue.clear ();
		Notfull.signal ();
		catch (Interruptedexception e) {e.printstacktrace ();
		} finally{Lock.unlock ();
	return retVal;
 }
}

Writetask_new.java simulate the thread class that produces the data

Package com.yulore.write;

public class Writetask_new implements Runnable {
	

	@Override public
	void Run () {for
		(int i=0;i<20;i++) {
//			try {
//Sleep				(m);			catch (Interruptedexception e) {
//				e.printstacktrace ();
			Writerqueue.getqueue (). Put ("for:" +i+ "Thread:" +thread.currentthread (). GetName ());
		}

	private void sleep (int millis) throws Interruptedexception {
		thread.sleep (Millis);
	}
	
}

Outputtask.java is responsible for writing data to a file

Package com.yulore.write;
Import Java.io.BufferedWriter;
Import Java.io.File;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.OutputStreamWriter;

Import java.util.LinkedList;
	
	public class Outputtask implements Runnable {private String fileName;
	Public Outputtask (String fileName) {this.filename = filename;
			@Override public void Run () {while (true) {try {5000);
			catch (Interruptedexception e) {e.printstacktrace ();
			} linkedlist<string> list = Writerqueue.getqueue (). Takeall ();
			Write2disk (list);
		list = null; }} private void Write2disk (linkedlist<string> list) {if List==null | |
			List.size () ==0) {System.out.println ("no data ...");
		Return
		
		} System.out.println ("Start serialization data" +filename);
		String Path = "d:/fbb/myworkspace_dw07/";
		
		File outputfile = new file (path+filename); if (Outputfile==null | |!
			Outputfile.exists ()) {try {outputfile.createnewfile (); catch (IoexcEption e) {e.printstacktrace ();
		} fileoutputstream out = null;
		OutputStreamWriter writer = null;
		
		BufferedWriter bw = NULL;
			try {out = new FileOutputStream (outputfile, true);
			writer = new OutputStreamWriter (out);
			
			BW = new BufferedWriter (writer);
				for (String content:list) {bw.write (content);
				Bw.newline ();
			Bw.flush ();
		} catch (IOException e) {e.printstacktrace ();
			}finally{try {if (bw!=null) bw.close ();
			catch (IOException e) {e.printstacktrace ();
	}} private void sleep (int millis) throws Interruptedexception {Thread.Sleep (Millis);
 }

}

Test class

Package com.yulore.write;

public class Testwrite {

	/**
	 * @param args
	 *
	/public static void main (string[] args) {
		
//		Test () ;
		test02 ();
	}

	private static void test02 () {
		writetask_new write = New writetask_new ();
		for (int i=0;i<4;i++) {
			new Thread (write). Start ();
		
		Outputtask output = new Outputtask ("Abc.txt");
		New Thread (Output). Start ();

	private static void Test () {
		Writetask write = new Writetask ("Abc.txt");
		for (int i=0;i<5;i++) {
			new Thread (write). Start ();