this is my first time posting here, so I'm not really sure what to say/ask.
Anyways, I am trying to make a simple java program that runs command prompt commands from the java program, mainly used for ping flood (ping flooding myself).
Here is my current code
public class Core extends JFrame {
JTextField ipTextField;
int packets = 0;
boolean running = false;
public Core() {
super("Fatique");
Container container = getContentPane();
JButton bAttack = new JButton("Start Attack");
JButton bStop = new JButton("Stop Attack");
JPanel jPanel = new JPanel();
container.setLayout(new FlowLayout());
ipTextField = new JTextField("IP Address", 30);
container.add(ipTextField);
bAttack.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String input = ipTextField.getText();
String[] value = input.split(":");
int amountOfPackets = Integer.parseInt(value[1]);
exec("cmd /c" + input + " -t -n " + amountOfPackets);
running = true;
}
});
bStop.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
stop();
}
});
if(!running) {
jPanel.add(bAttack);
} else {
jPanel.add(bStop);
}
add(jPanel);
}
public void exec(String cmd) {
try {
Process p = Runtime.getRuntime().exec(cmd);
System.out.println(getOutput(p) + " - " + getPacketsSent());
} catch (IOException e) {
e.printStackTrace();
}
}
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output = line;
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
public int getPacketsSent() {
return packets;
}
public void stop() {
exec("cmd /c break");
running = false;
}
public static void main(String[] args) {
Core c = new Core();
c.setSize(500, 300);
c.setVisible(true);
c.setResizable(false);
c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
c.setLocationRelativeTo(null);
}
I'm quite new at java, so that might not do what I want it to do.
What I want it to do is I enter an ip address in the textfield, and split it with ":", and after that the amount of packets, for instance
127.0.0.1:100
Though now when I try to use that ip and packet amount, it returns "null - 0" (from exec method), and I'm not even sure if it did anything related to ping.
What I am trying to accomplish is as I already said, ping flood myself, and then output whatever I get as response, though I have no idea if this code does anything even related to that, I mostly use logic when coding java.
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output = line;
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
Could someone explain me why my code code is not working how I want it to work? Please don't judge, as I already said, I'm quite new to java programming.
EDIT: Here is a quick "informative" explanation of what I am trying to accomplish.
I type in an ip address and how many packets I want to send. In this explanation, I am using localhost ip, and 5 packets.
I start the attack. At this part, I want the program to run cmd prompt command
ping 127.0.0.1 -t -n 5
127.0.0.1 being the ip that I put in the textfield in my program, and 5 is the amount of packets I put in the textfield.
I started the attack, so this is what should happen in the command prompt:
The language is Finnish, but still the same thing.
This is the basic explanation of what I am trying to accomplish, hopefully someone understood and can help/tell why my code is not working, or is working but not printing the proper lines in eclipse console.
There is a problem with your getOutput method. It looks like you intend to collect every line of output. But in fact, since you are assigning line to output, you will only return the last line before the end of stream.
To fix this, change
output = line;
to
output += line + "\n";
Or to be more correct:
output += line + LINE_SEPARATOR;
where you previously declared the latter as:
final String LINE_SEPARATOR = System.getProperty("line.separator");
That doesn't directly explain why you are getting null, but that might be because the command you are running is writing output to the 'error' stream rather than the 'output' stream.
Try something like this:
try {
Runtime rt = Runtime.getRuntime();
Process p = rt.exec("ping 192.168.16.67");
InputStream in = p.getInputStream();
OutputStream out = p.getOutputStream ();
InputStream err = p.getErrorStream();
p.destroy();
} catch(Exception exc) {}
Then, you'll have to read the out variable to parse the ping command output continuously.
bAttack.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String input = ipTextField.getText();
String[] value = input.split(":");
int amountOfPackets = Integer.parseInt(value[1]);
try {
p=Runtime.getRuntime().exec("ping -n "+amountOfPackets+" "+value[0]);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
running = true;
}
Just a small modification of your code. get output is as:
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output =output+ line+"\n";
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
Here output is JTextArea I have taken to display the output of PING process. I cannot show you the output because I lack reputation.
I don't know why first line is null. Anyway, it works.
Hope this help you. Have good time coding.
Related
I need my Java program to immediately stop if my VPN disconnects. I understand I can periodically run a command and parse the output, but this seems inefficient. I'm assuming it's possible to setup a receiver/listener instead but all the solutions I come across are Android oriented. Any recommendations?
Here's my approach (run every n seconds):
public boolean isConnected() {
boolean isConnected = false;
try {
Process p = Runtime.getRuntime().exec("cmd.exe /c netsh interface show interface");
BufferedReader stdin = new BufferedReader(
new InputStreamReader(p.getInputStream()));
String line;
while ((line = stdin.readLine()) != null) {
if (line.contains("Ethernet 2")) {
List<String> valueList = Arrays.asList(line.split("[\\s]{2,}"));
String connectedOrDisconnected = valueList.get(valueList.indexOf("Ethernet 2") - 2);
System.out.println("connectedOrDisconnected: " + connectedOrDisconnected);
isConnected = Objects.equals(connectedOrDisconnected, "Connected");
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
return isConnected;
}
I'm coding Julia script with ZeroMQ.
My goal is to communicate with ZMQ between two scripts. Here is an example:
# script1
using ZMQ
ctx = ZMQ.Context()
sockDealer = ZMQ.Socket(ctx, DEALER)
ZMQ.set_identity(sockDealer, "idA")
ZMQ.connect(sockDealer, "tcp://localhost:5555")
ZMQ.send(sockDealer, "hello world!")
ZMQ.close(sockDealer)
ZMQ.close(ctx)
#script2
using ZMQ
function pollrecv(socket::ZMQ.Socket,zmsg::Message)
rc = -1
while true
rc = ccall((:zmq_msg_recv, ZMQ.zmq), Cint, (Ptr{Message}, Ptr{Void}, Cint),
&zmsg, socket.data, ZMQ.ZMQ_DONTWAIT)
if rc == -1
# Base.Libc.EAGAIN = 11
# Problem unsolved: Failure to find Base.Libc.EAGAIN
if !(ZMQ.zmq_errno() == 11)
throw(ZMQ.StateError(ZMQ.jl_zmq_error_str()))
end
return false
else
ZMQ.get_events(socket) != 0 && notify(socket)
break
end
end
return true
end
ctx = ZMQ.Context()
sockRouter = ZMQ.Socket(ctx, ROUTER)
ZMQ.bind(sockRouter, "tcp://*:5555")
fini = false
while !fini
println("listening...")
idSock = Message()
while pollrecv(sockRouter, idSock)
msg = ZMQ.recv(sockRouter)
println("msg recv: " * bytestring(msg))
fini = true
end
sleep(1)
end
ZMQ.close(sockRouter)
ZMQ.close(ctx)
I can execute them with Julia on the command prompt. Everything goes fine. Script 2 can receive the message of Script 1.
Now, I need to execute them from Java. Meaning that I need to create a java project which is just like a controller. Here is my Java project:
public class Container {
private Vector<String[]> commands;
public Container() {
this.commands = new Vector<String[]>();
}
public void addCommand(String[] strs) {
this.commands.addElement(strs);
}
public void execute() {
for(int i = 0; i < this.commands.size(); i++) {
try {
Process p = Runtime.getRuntime().exec(this.commands.get(i));
if(p.waitFor() != 0){
System.err.println("exit value = " + p.exitValue());
}
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
StringBuffer stringBuffer = new StringBuffer();
String line = null;
while((line = in.readLine()) != null){
stringBuffer.append(line + "-");
}
System.out.println(stringBuffer.toString());
} catch (IOException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
} catch(InterruptedException e){
System.err.println(e);
}
}
}
}
//main
public class Main {
public static void main(String[] args) {
Container c = new Container();
String[] script1 = {"/usr/bin/julia", "/home/thomas/Julia/script1.jl"};
String[] script2 = {"/usr/bin/julia", "/home/thomas/Julia/script2.jl"};
c.addCommand(script1);
c.addCommand(script2);
c.execute();
}
}
However, when I run my java project, I can see that it keeps running but I can't see anything on the console: no result, no message, no error.
I think there is something wrong in my java project.
You'll want to run the two scripts concurrently: script2 is the server script, so it should be running when you run script1. As it is now, Process.waitFor() will wait for script1, the client script, to complete, before executing the server script script2 in the next for iteration.
You could start them as such:
String[] clientScript = { "/usr/bin/julia", "/home/thomas/Julia/script1.jl" };
String[] serverScript = { "/usr/bin/julia", "/home/thomas/Julia/script2.jl" };
Process server = Runtime.getRuntime().exec(serverScript);
Process client = Runtime.getRuntime().exec(clientScript);
and instantiate two threads to read their outputs:
(new ProcessReader(server)).start();
(new ProcessReader(client)).start();
using
public class ProcessReader extends Thread {
private Process p;
public ProcessReader(Process p) {
this.p = p;
}
#Override
public void run() {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
try {
String line;
while ((line = in.readLine()) != null) {
System.out.println("Read: " + line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
Although, since the clientScript doesn't produce any output, you could just
start the scripts, and only read the output from the server script - no thread needed.
There's one more thing to consider: the serverScript must be listening... before the clientScript attempts to connect. So you may want to do this:
Process server = Runtime.getRuntime().exec(serverScript);
BufferedReader in = new BufferedReader(new InputStreamReader(server.getInputStream()));
if ( in.readLine().equals("listening...") ) {
Process client = Runtime.getRuntime().exec(clientScript);
String line;
while ( (line=in.readLine()) != null )
System.out.println("Read: " + line );
}
Since this is not a specific answer to your question, this may help to you or other users that attempt to similar jobs.
JuliaCaller is an early stage library for calling Julia from Java. It executes the Julia executable as a Java process and runs a script in the Julia side. This script opens a TCP server that listens on a given port number. Every command, statement or expression sent from Java is then executed and results are sent back to Java in JSON format.
This library also implements the standard javax.script interface, that means, Julia libraries, functions, and programs can run like a scripting language that is implemented in Java (mimics).
Here is the example:
Constants.setProperties(Constants.JULIA_PATH, "/usr/local/bin/julia");
Constants.setProperties(Constants.JULIA_PORT, "8001");
// Creating a scripting interface for Julia
manager = new ScriptEngineManager();
engine = manager.getEngineByName("Julia");
// Sending command 'a = 3' to Julia from Java
engine.eval("a = 3");
// Handling the result in Java
Object a = engine.get("a");
More examples are given in the GitHub page.
Source code with Apache License
I am using inheritIO() to redirect output from a child process in my program to the System.out and System.err, and input to System.in.
These are all redirected by System.setOut() and the like:
// Reassign System IO
System.setIn(cpanel.getConsole().getInputStream());
System.setOut(new PrintStream(cpanel.getConsole().getOutputStream()));
System.setErr(new PrintStream(cpanel.getConsole().getOutputStream()));
However when I run the process:
String[] fullargs = new String[sargs.length+4];
fullargs[0] = "java";
fullargs[1] = "-classpath"; // Runtime classpath option.
fullargs[2] = cpath; // Specify the classpath.
fullargs[3] = mname; // Specify class to run.
for(int i=0; i<sargs.length; i++)
{
fullargs[i+4] = sargs[i]; // Put together arguments.
}
ProcessBuilder proc = new ProcessBuilder()
.inheritIO()
.command(fullargs);
try
{
System.out.println("RUNNING...");
proc.start();
}
catch(IOException ioe)
{
JOptionPane.showMessageDialog(null,
"There was a system error invoking this program.",
"ERROR",
JOptionPane.ERROR_MESSAGE);
}
It redirects to what used to be System.out etc. rather than what they've been redirected to.
If I comment out the inheritIO() line, the output is lost to time and doesn't appear anywhere. With inheritIO() it goes to the standard console of the parent process rather than the redirected one. The line where I print "RUNNING" goes to the proper redirected location. In other words, inheritIO() is doing exactly what it should if I hadn't redirected the output streams of the parent process. It's going to the parent process's old console.
I have no idea why this is happening and I'm pulling my hair out here. I've seen that inheritIO() doesn't work in Windows, but this issue is the same on Mac OS and Linux. I'm using Java 7.
Please note my answer here: https://stackoverflow.com/a/32350856/5226711
Applied to your question, this means you can use an adapted verion of the StreamGobbler proposed in https://stackoverflow.com/a/14165567/5226711:
private class StreamGobbler extends Thread {
private InputStream in;
private PrintStream out;
private StreamGobbler(InputStream in, PrintStream out) {
this.in = in;
this.out = out;
}
#Override
public void run() {
try {
BufferedReader input = new BufferedReader(new InputStreamReader(in));
String line = null;
while ((line = input.readLine()) != null)
out.println(line);
} catch (IOException e) {
e.printStackTrace();
}
}
}
And use it like this:
String[] fullargs = new String[sargs.length+4];
fullargs[0] = "java";
fullargs[1] = "-classpath"; // Runtime classpath option.
fullargs[2] = cpath; // Specify the classpath.
fullargs[3] = mname; // Specify class to run.
for(int i=0; i<sargs.length; i++)
{
fullargs[i+4] = sargs[i]; // Put together arguments.
}
ProcessBuilder pb = new ProcessBuilder().command(fullargs);
try
{
System.out.println("RUNNING...");
Process p = pb.start();
StreamGobbler pOut = new StreamGobbler(p.getInputStream(), new PrintStream(cpanel.getConsole().getOutputStream()));
StreamGobbler pErr = new StreamGobbler(p.getErrorStream(), new PrintStream(cpanel.getConsole().getOutputStream()));
pOut.start();
pErr.start();
}
catch(IOException ioe)
{
JOptionPane.showMessageDialog(null,
"There was a system error invoking this program.",
"ERROR",
JOptionPane.ERROR_MESSAGE);
}
Redirecting stdin of the child is not included in my example.
i wanted to read the output-stream of a c-Application in my Java program. iremoted (available here: Link) is a C-Application that puts out seperate lines like "0x19 pressed" if a button on my Apple Remote is pressed. If i start the iremoted program everything is doing well and these separate lines are shown on my screen everytime I pressed a button.
Now I wanted to read the output-stream of the c-application in my Java application to process inputs of the Apple Remote in Java projects.
Unfortunately i don't know why no input is regocnized?
I tried it with a simple HelloWorld.c program and my program responded as intended in this case (prints out HelloWorld).
Why doensn't it work with the iremoted program?
public class RemoteListener {
public void listen(String command) throws IOException {
String line;
Process process = null;
try {
process = Runtime.getRuntime().exec(command);
} catch (Exception e) {
System.err.println("Could not execute program. Shut down now.");
System.exit(-1);
}
Reader inStreamReader = new InputStreamReader(process.getInputStream());
BufferedReader in = new BufferedReader(inStreamReader);
System.out.println("Stream started");
while((line = in.readLine()) != null) {
System.out.println(line);
}
in.close();
System.out.println("Stream Closed");
}
public static void main(String args[]) {
RemoteListener r = new RemoteListener();
try {
r.listen("./iremoted"); /* not working... why?*/
// r.listen("./HelloWorld"); /* working fine */
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
stdout is buffered and it's not automatically flushed if you are not writing to screen. Add:
fflush(stdout);
after:
printf("%#lx %s\n", (UInt32)event.elementCookie,
(event.value == 0) ? "depressed" : "pressed");
iremoted is likely writing to stderr if a hello world program works. You would want the error stream in that case. I'm not sure how this works for your hello world case - I think you're doing the wrong thing here:
new InputStreamReader(process.getInputStream());
should be
new InputStreamReader(process.getOutputStream());
or
new InputStreamReader(process.getErrorStream());
I am trying to run some shell scripts for Java by using commons exec package and clear the STDOUT & STDERR buffers by using PumpStreamHandler. Most of the scripts run fine without any problems but some of them hangs.
Particularly those scripts that takes some time to return. My guess is that the PumpStramHandle might be reading end of stream as there is nothing put on the stream for a while and after that the buffers fill up.
Is there any better way to get across this problem?
Extract the script/command being executed and run it yourself in a shell. When running things that are 'exec'd through some other language(c,c++, python java etc) and things start going 'wrong' this should be the first step.
You find all sorts of things going on. Scripts that stop and prompt for input(big source of hangups) errors that don't parse correctly, seg faults, files not found.
To expand on the first answer about running the commands directly to test, you can test your hypothesis with a simple script that sleeps for a while before returning output. If you
can't test your command, test your idea.
#!/bin/bash
sleep 60;
echo "if you are patient, here is your response"
Not the best solution. But does what I need. :)
class OSCommandLogger extends Thread {
private static final Logger logger = Logger.getLogger(OSCommandLogger.class);
private volatile boolean done = false;
private final String name;
// Each process is associated with an error and output stream
private final BufferedReader outputReader;
private final BufferedReader errorReader;
private final Logger log;
/**
* Reads the output & error streams of the processes and writes them to
* specified log
*
* #param p
* #param name
* #param log
*/
OSCommandLogger(Process p, String name, Logger log) {
// Create readers
outputReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
errorReader = new BufferedReader(new InputStreamReader(p.getErrorStream()));
this.log = log;
if (name != null)
this.name = name;
else
this.name = "OSCommandStreamsLogger";
}
private void logLine(BufferedReader reader, boolean isError) {
try {
String line = null;
while ((line = reader.readLine()) != null) {
if (log != null && log.isDebugEnabled()) {
if (!isError)
log.debug("[OuputStream] " + line);
else
log.warn("[ErrorStream] " + line);
} else
logger.debug(line);
}
} catch (Exception ex) {
if (log != null)
log.error(name + ":" + "Error while reading command process stream", ex);
}
}
public void run() {
while (!done) {
logLine(outputReader, false);
logLine(errorReader, true);
try {
// Sleep for a while before reading the next lines
Thread.sleep(100);
} catch (InterruptedException e) {
log.debug("Done with command");
}
}
// Process is done. Close all the streams
try {
logLine(outputReader, false);
outputReader.close();
logLine(errorReader, true);
errorReader.close();
if (log != null && log.isDebugEnabled())
log.debug(name + ": Closed output/ error Streams.");
} catch (IOException ie) {
if (log != null)
log.error(name + ":" + "Error while reading command process stream", ie);
}
}
public void stopLoggers() {
if (log != null && log.isDebugEnabled())
log.debug(name + ":Stop loggers");
this.done = true;
}
}
Usage:
Process p = Runtime.getRuntime().exec("Command");
OSCommandLogger logger = new OSCommandLogger(p, "Command", log);
// Start the thread using thread pool
threadExec.executeRunnable(logger);
int exitValue = p.waitFor(); // Wait till the process is finished
// Required to stop the logger threads
logger.stopLoggers();
logger.interrupt();