Im making a brute force program that can crack SHA1 codes. Im very new to using threads I want to use them to speed up the application by running in parallell. Can anyone help me and stop jframe freezing. the threads work and produce the correct answers but never allows me to use jframe again.
code im using for threads:
public class crack1 extends Thread {
char[] pass1 = new char[1];
public boolean crack11() {
// while(!exit){
for (int i = 0; i < length; i++) {
pass1[0] = alpha1[i];
if (compareit(input, pass1) == true) {
System.out.println(String.valueOf("password =" + pass1[0]));
return true;
}
}
return false;
}
private boolean cracker(String input) {
crack1 obj1 = new crack1();
crack2 obj2 = new crack2();
crack3 obj3 = new crack3();
crack4 obj4 = new crack4();
crack5 obj5 = new crack5();
crack6 obj6 = new crack6();
if (obj1.crack11() == true) {
jTextArea1.append("password found");
System.out.println("password found");
}
// obj2.run();
// obj3.run();
// obj4.run();
// obj5.run();
// obj6.run();
System.out.println("done");
}
public static boolean compareit(String input, char[] test) {
System.out.println(String.valueOf(test));
String answer = String.valueOf(test);
String check = sha1(String.valueOf(test));
if (input.equals(check)) {
// jTextArea1.append("password ="+answer);
// System.out.println(String.valueOf("password ="+answer));
return true;
} else {
return false;
}
}
}
//obj2.run();
That is not how you use a Thread. Invoking the run() method directly will just cause the code to execute on the current Thread.
To have the code execute on a separate Thread you need to use:
obj2.start();
Related
I'm currently working on a Java TD game. I have a class called "Wave" that holds the enemy types to spawn (that all extend the class "Enemy") and the delay between the spawns.
public class Wave {
*I dunno what*[] enemyTypes;
int[] delays;
private Point spawnPoint;
Wave(*I dunno what*[] enemyTypes, int[] delays, Point spawnPoint) {
this.enemyTypes = enemyTypes;
this.delays = delays;
this.spawnPoint = spawnPoint;
}
void spawnWave() {
for (int i = 0; i < enemyTypes.length; i++) {
try {
Thread.sleep(delays[i]);
} catch (InterruptedException e) {
e.printStackTrace();
}
Point sP = new Point(spawnPoint);
*The enemy type to spawn* enemy = new *The enemy type to spawn*.spawn(sP);
}
}
}
I don't know how to code the bits within the **
What about something like this?
You can get more information at Oracle Java Documentation
public class Wave<T extends Enemy> {
List<T> enemyTypes;
int[] delays;
private Point spawnPoint;
Wave(int[] delays, Point spawnPoint) {
this.enemyTypes = new ArrayList<>();
this.delays = delays;
this.spawnPoint = spawnPoint;
}
boolean addEnemy(T enemy) {
if(enemyTypes.contains(enemy)) {
return false;
}
this.enemyTypes.add(enemy);
return true;
}
void spawnWave() {
for (int i = 0; i < enemyTypes.size(); i++) {
try {
Thread.sleep(delays[i]);
} catch (Exception e) {}
Point sP = new Point(spawnPoint);
Enemy enemy = enemyTypes.get(i);
enemy.spawn(sP);
}
}
}
looks like a use case for factory pattern
you can provide array of factories for your enemy classes
I want to read multiple files through multi threading I wrote the code for the same but my threads are executing one by one which is very time consuming. I wants them to run simultaneously.
Please correct me what I am doing wrong in the below code where I am doing this by implementing the callable interface because I have to read the file and set its data into the variable of Model object and after that I am returning the list of objects.
Thanks In advance.
Class A{
ExecutorService executor = getExecuterService();
private ExecutorService getExecuterService() {
int threadPoolSize = Runtime.getRuntime().availableProcessors() - 1;
System.out.println("Number of COre" + threadPoolSize);
return Executors.newFixedThreadPool(threadPoolSize);
}
#SuppressWarnings({ "unused", "unchecked" })
FutureTask<List<DSection>> viewList = (FutureTask<List<DSection>>) executor
.submit(new MultiThreadedFileReadForDashboard(DashboardSectionList, sftpChannel,customQuery));
executor.shutdown();
while (!executor.isTerminated()) {
}
}
Class for task:
public class MultiThreadedFileReadForDashboard implements Callable {
public MultiThreadedFileReadForDashboard(List<DSection> dashboardSectionList, ChannelSftp sftpChannel,
CustomQueryImpl customQuery) {
this.dashboardSectionList = dashboardSectionList;
this.sftpChannel = sftpChannel;
this.customQuery = customQuery;
}
public List<DSection> call() throws Exception {
for (int i = 0; i < dashboardSectionList.size(); ++i) {
DSection DSection = dashboardSectionList.get(i);
List<LView> linkedViewList = new ArrayList<LView>(DSection.getLinkedViewList());
LView lView;
for (int j = 0; j < linkedViewList.size(); ++j) {
lView = linkedViewList.get(j);
int UserQueryId = Integer.parseInt(lView.getUserQueryId());
outputFileName = customQuery.fetchTableInfo(UserQueryId);
if ((outputFileName != null) && (!outputFileName.equalsIgnoreCase(""))) {
String data = readFiles(outputFileName);
lView.setData(data);
} else {
lView.setData("No File is present");
}
}
if (size == dashboardSectionList.size()) {
break;
}
}
return dSectionList;
}
private String readFiles(String outputFileName) {
String response = null;
try {
InputStream in = sftpChannel.get(outputFileName);
BufferedReader br = new BufferedReader(new InputStreamReader(in, "UTF-8"));
StringBuilder inputData = new StringBuilder("");
String line = null;
while ((line = br.readLine()) != null) {
inputData.append(line).append("\n");
}
JSONArray array = null;
if (outputFileName.toLowerCase().contains("csv")) {
array = CDL.toJSONArray(inputData.toString());
} else {
}
response = array.toString();
} catch (Exception e) {
e.printStackTrace();
}
return response;
// TODO Auto-generated method stub
}
}
}
I do not see read multiple files through multi threading. I see one task invoked by the ExecuterService and it is reading all the files. the multi threading feature is achieved by submitting multiple tasks to the ExecuterService, each is given one file to process (can be by constructor).
Here is what I think you should do:
inside the inner for loop, you construct a task that is given outputFileName in constructor and submit it to the executor, getting back a Future instance. after all tasks were submitted, you will have a List<Future> that you can query to see when they are done and get result. the task will call readFiles() (odd name for a method that reads one file...)
I am using Fork join pool in java for multitasking. Now i came across a situation where, for every task, I need to hit a url then wait for 10 minutes and then again hit another url to read the data. Now the problem is that for those 10 minutes my CPU is idle and not starting another tasks ( more than those defined in fork join pool).
static ForkJoinPool pool = new ForkJoinPool(10);
public static void main(String[] args){
List<String> list = new ArrayList<>();
for(int i=1; i<=100; i++){
list.add("Str"+i);
}
final Tasker task = new Tasker(list);
pool.invoke(task);
public class Tasker extends RecursiveAction{
private static final long serialVersionUID = 1L;
List<String> myList;
public Tasker(List<String> checkersList) {
super();
this.myList = checkersList;
}
#Override
protected void compute() {
if(myList.size()==1){
System.out.println(myList.get(0) + "start");
//Date start = new Date();
try {
Thread.sleep(10*60*1000);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(myList.get(0) + "Finished");
}
else{
List<String> temp = new ArrayList<>();
temp.add( myList.get( myList.size()-1 ) );
myList.remove( myList.size()-1 );
Tasker left = new Tasker(myList);
Tasker right = new Tasker(temp);
left.fork();
right.compute();
left.join();
}
}
Now What should I do so that CPU picks all the tasks and then wait parallaly for them.
Unfortunately, ForkJoinPool does not work well in the face of Thread.sleep(), because it designed for many short tasks that finish quickly, rather than tasks that block for a long time.
Instead, for what you are trying to accomplish, I would recommend using ScheduledThreadPoolExecutor and dividing your task into two parts.
import java.util.*;
import java.util.concurrent.*;
public class Main {
static ScheduledThreadPoolExecutor pool = new ScheduledThreadPoolExecutor(10);
public static void main(String[] args){
for(int i=1; i<=100; i++){
pool.schedule(new FirstHalf("Str"+i), 0, TimeUnit.NANOSECONDS);
}
}
static class FirstHalf implements Runnable {
String name;
public FirstHalf(String name) {
this.name = name;
}
public void run() {
System.out.println(name + "start");
pool.schedule(new SecondHalf(name), 10, TimeUnit.MINUTES);
}
}
static class SecondHalf implements Runnable {
String name;
public SecondHalf(String name) {
this.name = name;
}
public void run() {
System.out.println(name + "Finished");
}
}
}
If Java provides a thread pool which allows releasing the underlying resources (that is, the kernel thread participating in the thread pool) during a Thread.sleep(), you should use that instead, but I currently do not know of one.
According to docs forkJoin basic use section tells:
if (my portion of the work is small enough)
do the work directly
else
split my work into two pieces
invoke the two pieces and wait for the results
Hopefully this meets your need if you are using forkjoin
public class Tasker extends RecursiveAction {
static ForkJoinPool pool = new ForkJoinPool(10);
static int threshold = 10;
public static void main(String[] args){
List<String> list = new ArrayList<>();
for(int i=1; i<=100; i++){
list.add("Str"+i);
}
final Tasker task = new Tasker(list);
pool.invoke(task);
}
private static final long serialVersionUID = 1L;
List<String> myList;
public Tasker(List<String> checkersList) {
super();
this.myList = checkersList;
}
void computeDirectly() {
for(String url : myList){
System.out.println(url + " start");
}
//Date start = new Date();
try {
//keep hitting url
while (true) {
for(String url : myList) {
//url hitting code here
System.out.println(url + " hitting");
}
Thread.sleep(10 * 60 * 1000);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for(String url : myList){
System.out.println(url + " Finished");
}
}
#Override
protected void compute() {
if (myList.size() <= threshold) {
computeDirectly();
return;
}
//temp list have only one url
//List<String> temp = new ArrayList<>();
//temp.add( myList.get( myList.size()-1 ) );
//myList.remove( myList.size()-1 );
//Tasker left = new Tasker(myList);
//Tasker right = new Tasker(temp);
//left.fork();
//right.compute();
//left.join();
List<String> first = new ArrayList<>();
List<String> second = new ArrayList<>();
//divide list
int len = myList.size();
int smHalf = len / 2;//smaller half
first = myList.subList(0, smHalf);
second = myList.subList(smHalf + 1, len);
invokeAll(new Tasker(first), new Tasker(second));
}
}
I'm new to JavaScript and am trying to make an app that opens with an animation of text typing itself. This is the JavaScript version of the self-typing text I found in another question:
var text = "The quick fox jumped over the lazy dog.";
var charCount = text.length;
var currentLetterCount = 0;
var speed = 100; // How fast should it type?
var $input = document.getElementById("someInput");
function writeLetter() {
var currentText = $input.value;
var currentLetter = text.charAt(currentLetterCount);
currentLetterCount++;
$input.value = currentText + currentLetter;
if(currentLetterCount == charCount)
clearInterval(timerId);
}
var timerId = setInterval(writeLetter, speed);
I'm basically looking to convert that into Java. Please help, many thanks!
Java Version of Above code:
Class LetterDisplay(){
public String text = "The quick fox jumped over the lazy dog.";
public int charCount = text.length;
public int currentLetterCount = 0;
public int speed = 100; // How fast should it type?
TextView textarea = (TextView)findViewById(R.id.tv);
public static void main(String[] args){
LetterDisplay mainObj = new LetterDisplay();
Runnable r = new MyThread(mainObj);
new Thread(r).start();
}
public class MyThread implements Runnable {
public MyThread(Object parameter) {
// store parameter for later user
}
public void run() {
try {
doRun();
} finally {
notifyListeners();
}
public doRun(){
String currentText = textarea.getText();
char currentLetter = text.charAt(currentLetterCount);
currentLetterCount++;
textarea.setText(currentText + currentLetter);
if(currentLetterCount == charCount)
Thread.stop(); // this is Evil way to Stop a Thread
}
try{ Thread.Sleep(speed); } catch(Exception e){}
}
}
}
i hopes this help...
Hello I have a problem wherein I have to read a huge csv file. remove first field from it, then store only unique values to a file. I have written a program using threads which implements producer-consumer pattern.
Class CSVLineStripper does what the name suggests. Takes a line out of csv, removes first field from every line and adds it to a queue. CSVLineProcessor then takes that field stores all one by one in an arraylist and checks if fields are unique so only uniques are stored. Arraylist is only used for reference. every unique field is written to a file.
Now what is happening is that all fields are stripped correctly. I run about 3000 lines it's all correct. When I start the program for all lines, which are around 7,00,000 + lines, i get incomplete records, about 1000 unique are not taken. Every field is enclosed in double-quotes. What is weird is that the last field in the file that is generated is an incomplete word and ending double quote is missing. Why is this happening?
import java.util.*;
import java.io.*;
class CSVData
{
Queue <String> refererHosts = new LinkedList <String> ();
Queue <String> uniqueReferers = new LinkedList <String> (); // final writable queue of unique referers
private int finished = 0;
private int safety = 100;
private String line = "";
public CSVData(){}
public synchronized String getCSVLine() throws InterruptedException{
int i = 0;
while(refererHosts.isEmpty()){
if(i < safety){
wait(10);
}else{
return null;
}
i++;
}
finished = 0;
line = refererHosts.poll();
return line;
}
public synchronized void putCSVLine(String CSVLine){
if(finished == 0){
refererHosts.add(CSVLine);
this.notifyAll();
}
}
}
class CSVLineStripper implements Runnable //Producer
{
private CSVData cd;
private BufferedReader csv;
public CSVLineStripper(CSVData cd, BufferedReader csv){ // CONSTRUCTOR
this.cd = cd;
this.csv = csv;
}
public void run() {
System.out.println("Producer running");
String line = "";
String referer = "";
String [] CSVLineFields;
int limit = 700000;
int lineCount = 1;
try {
while((line = csv.readLine()) != null){
CSVLineFields = line.split(",");
referer = CSVLineFields[0];
cd.putCSVLine(referer);
lineCount++;
if(lineCount >= limit){
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("<<<<<< PRODUCER FINISHED >>>>>>>");
}
private String printString(String [] str){
String string = "";
for(String s: str){
string = string + " "+s;
}
return string;
}
}
class CSVLineProcessor implements Runnable
{
private CSVData cd;
private FileWriter fw = null;
private BufferedWriter bw = null;
public CSVLineProcessor(CSVData cd, BufferedReader bufferedReader){ // CONSTRUCTOR
this.cd = cd;
try {
this.fw = new FileWriter("unique_referer_dump.txt");
} catch (IOException e) {
e.printStackTrace();
}
this.bw = new BufferedWriter(fw);
}
public void run() {
System.out.println("Consumer Started");
String CSVLine = "";
int safety = 10000;
ArrayList <String> list = new ArrayList <String> ();
while(CSVLine != null || safety <= 10000){
try {
CSVLine = cd.getCSVLine();
if(!list.contains(CSVLine)){
list.add(CSVLine);
this.CSVDataWriter(CSVLine);
}
} catch (Exception e) {
e.printStackTrace();
}
if(CSVLine == null){
break;
}else{
safety++;
}
}
System.out.println("<<<<<< CONSUMER FINISHED >>>>>>>");
System.out.println("Unique referers found in 30000 records "+list.size());
}
private void CSVDataWriter(String referer){
try {
bw.write(referer+"\n");
} catch (Exception e) {
e.printStackTrace();
}
}
}
public class RefererCheck2
{
public static void main(String [] args) throws InterruptedException
{
String pathToCSV = "/home/shantanu/DEV_DOCS/Contextual_Work/excite_domain_kw_site_wise_click_rev2.csv";
CSVResourceHandler csvResHandler = new CSVResourceHandler(pathToCSV);
CSVData cd = new CSVData();
CSVLineProcessor consumer = new CSVLineProcessor(cd, csvResHandler.getCSVFileHandler());
CSVLineStripper producer = new CSVLineStripper(cd, csvResHandler.getCSVFileHandler());
Thread consumerThread = new Thread(consumer);
Thread producerThread = new Thread(producer);
producerThread.start();
consumerThread.start();
}
}
This is how a sample input is:
"xyz.abc.com","4432"."clothing and gifts","true"
"pqr.stu.com","9537"."science and culture","false"
"0.stu.com","542331"."education, studies","false"
"m.dash.com","677665"."technology, gadgets","false"
Producer stores in queue:
"xyz.abc.com"
"pqr.stu.com"
"0.stu.com"
"m.dash.com"
Consumer stores uniques in the file, but after opening file contents one would see
"xyz.abc.com"
"pqr.stu.com"
"0.st
Couple things, you are breaking after 700k, not 7m, also you are not flushing your buffered writer, so the last stuff you could be incomplete, add flush at end and close all your resources. Debugger is a good idea :)