Using Runtime in servlet
Hi,
I am using the Runtime class to execute some code that will send the user an email when they create an account on the website. For some reason the emails are taking a very long time ( a couple hours) to arrive whereas when executing the command from the command line the mail will take only a minute. I guess this code would execute in another thread so would this thread have to wait for some reason for such a long time? Thanks a lot.
Process proc = runtime.exec("/bin/bash");
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(proc.getOutputStream()));
String command = "echo " + message + "| mail -s " + SUBJECT + " " + e;
out.write(command, 0, command.length());
out.flush();
...
If you want to send mail, do it using JavaMail. If you insist on trying to use the shell then I guess you must have a carriage return or a new line at the end of that command. (I don't really know which one, cause I'm a Windows user)
Similar Messages
-
How to execute an application in Solaris using Runtime.getRuntime.exec() ?
I am currently doing a project which requires the execution of Solaris applications through the use of Java Servlet with this Runtime method - Runtime.getRuntime.exec()
This means that if the client PC tries to access the servlet in the server PC, an application is supposed to be executed and launched on the server PC itself. Actually, the servlet part is not an issue as the main problem is the executing of applications in different platforms which is a big headache.
When I tried running this program on a Windows 2000 machine, it works perfectly fine. However, when I tried it on a Solaris machine, nothing happens. And I mean nothing... no errors, no nothing. I really don't know what's wrong.
Here's the code.
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Process process; Runtime runtime = Runtime.getRuntime();
String com= "sh /opt/home/acrobat/";
String program = request.getParameter("program");
try
process = runtime.exec(com);
catch (Exception e)
out.println(e);
It works under Windows when com = "c:\winnt\system32\notepad.exe"
When under Solaris, I have tried everything possible. For example, the launching of the application acrobat.
com = "/opt/home/acrobat"
com = "sh /opt/home/acrobat"I have also tried reading in the process and then printing it out. It doesn't work either. It only works when excuting commands like 'ls'
BufferedReader read = new BufferedReader(new InputStreamReader(process.getInputStream()));Why is it such a breeze to execute prgrams under Windows while there are so many problems under Solaris.
Can some experts please please PLEASE point out the errors and give me some advice and help to make this program work under Solaris! Please... I really need to do this!!
My email address - [email protected]
I appreciate it.
By the way, I'm coding and compiling in a Windows 2000 machine before ftp'ing the .class file to the Solaris server machine to run.it is possible that you are trying to run a program that is going to display a window on an X server, but you have not specified a display. You specifiy a display by setting the DISPLAY environment variable eg.
setenv DISPLAY 10.0.0.1:0
To check that runtime.exec is working you should try to run a program that does not reqire access to an X Server. Try something like
cmd = "sh -c 'ls -l > ~/testlist.lst'";
alternatively try this
cmd = "sh -c 'export DISPLAY=127.0.0.1:0;xterm '"
you will also need to permit access to the X server using the xhost + command -
A while back I was trying to get input on what could be going wrong with having a servlet use runtime to execute a batch file. I still haven't figured it out. Is it even possible for me to do it, or am I burning time by messing with it, due to security restrictions or something?
Thanks,Can you run this batch file from an ordinary application? If not, stop worrying about servlets and security and start worrying about how to use Runtime.exec().
You'll find numerous posts about Runtime.exec() in the Java Programming forum, and many of them have links to the Javaworld article about its many pitfalls. -
How to upload more than 100mb in using com.oreilly.servlet package
hi all,
I use com.oreilly.servlet package to upload and i use the following code to upload
MultipartRequest mr = new MultipartRequest(request,"/tmp/saved",0x10000000);My problem is i can't upload more than 25mb, uploads upto 25mb and shows page cannot displayed err in IE,
Pls helpIn the webserver there is most likely a configuration option for the maximum size that a request may have. So search through the manual of your particular webserver on how to change that.
-
Executing a command using Runtime Class
How to execute a command on a differnet machine with different ipaddress using Runtime Class
My code is
String[] cmd = new String[3];
cmd[0] = "192.1...../c:/WINNT/system32/cmd.exe" ;
cmd[1] = "/C" ;
cmd[2] = args[0];
Runtime rt = Runtime.getRuntime();
System.out.println("Execing " + cmd[0] + " " + cmd[1]
+ " " + cmd[2]);
Process proc = rt.exec(cmd);
// any error???
int exitVal = proc.waitFor();
System.out.println("ExitValue: " + exitVal);
This is not WorkingI have same issue. Actually when I use cmd.exe /c set in java code and if I run the java code in DOS propmt, it retrieves all latest user Environment variable values. But if I run the code in windows batch file, it is not retrieveing the latest user environment values until I reboot my computer, Do you know how to get user environment value with out rebooting machine??????
-
Monitoring a Process using Runtime.exce()
Hi,
In my Program, I'm using the
new BufferedReader(new InputStreamReader(Runtime.getRuntime() .exec("ps -ef | grep xmlfeed").getInputStream()));
The above statement is not returning any inputstream to the BuffredReader.
When I gave the command as "PWD", it's returning the lines as expected.
But it's not working even for "PS" command also.I'm running this in AIX machine.
Any Ideas,Please help....
Edited by: haijdp on Dec 21, 2007 1:11 AMHello! And sorry I didn't reply earlier. I hope the Original Poster will find revisit this thread and it helps him.
From your post I assumed that you were not a student trying to create some homework. That's why I felt free to simply code a solution and submit the code here. But first some remarks:
I don't think that your code can work. Runtime.exec expects an array of type String, where the first element is the command and subsequent elements are a command line option each. I don't think you can use the pipe and call several commands using Runtime.exec, but that's just a kind of guess. YMMV.
Running external Processes in Java is a bit complicated. Basically,
* It's good to run the process in it's own thread. That way the main program can continue without getting stuck.
* To extract stdout and stderr of your target process you must run two threads, one for stderr and one for stdout. Both threads extract the characters of their respective streams in a loop that runs inside the thread. Again, that way we avoid deadlocks, program getting stuck etc.
This explanation is terrible, I know - I think a slice of source code speaks louder than words. I have attached five java files which together make a little process runner which extracts stdout and stderr in a safe manner. To run:
* Cut'n paste them into five text files, one per class.
* Save the each text file as {contained-class-name}.java
* Compile the stuff
* Run RunnerDemo (When I ran it, I got a directory listing printed on the console)
Explanation sounds a bit sloppy, but I did it under the assumption that you are a seasoned java pro, so it should not pose any problems. Since you seem to be a different OS than I (AIX, I run Linux), the command may or may not work. Try other commands. For example, in the RunnerDemo class you could set the cmd field to this:
String [] cmd =
"ps",
"-A",
"-H"
};This would give you a process listing (works on Linux).
By the way, commands are passed as array. See Java documentation for java.lang.Runtime.exec (String []) for explanation of this array.
One problem I see in your command is that the output of ps is piped to some other program. Sorry, I don't know whether my code could achieve this. All it can do is to rum one single command with command line options. But you should be able to adjust the given example, so it supports piping to another program.
If you have any further questions, please don't hesitate to ask!
Class: RunnerDemo
* RunnerDemo.java
* Demo for the process runner
package rtimeexec;
public class RunnerDemo
public static void main (String [] args)
String [] cmd =
"ls",
"-a",
"-l"
ProcessRunner runner;
String stdOutStr;
String stdErrStr;
runner = new ProcessRunner (cmd);
runner.start ();
runner.BlockUntilFinished ();
stdOutStr = runner.GetStdOutText ();
stdErrStr = runner.GetStdErrText ();
System.out.println ("Process result, ls -a -l");
System.out.println ("-----------------------------------------------------------------------");
System.out.println ("Stdout:");
System.out.println ("-----------------------------------------------------------------------");
System.out.println (stdOutStr);
System.out.println ();
System.out.println ("-----------------------------------------------------------------------");
System.out.println ("Stderr:");
System.out.println ("-----------------------------------------------------------------------");
System.out.println (stdErrStr);
Class: ProcessRunner
package rtimeexec;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
* Runs a system process and extracts stdout and stderr of that process.
* Process will run in its own thread, so that the caller can simply continue
* with less of a chance to get locked down. Caller can invoke the {@link BlockUntilFinished}
* method after starting this thread. This method blocks until the thread is finished,
* i.e. the process has finished.
* Unfortunately, we haven't implemented any facility to stream characters to
* stdin of the process called. If that facility would exist we could refactor
* the classes and realize some sort of piping facility, as it's possible in
* Linux, for example.
* Example on how to run a process:
* <pre>
* String [] cmd = {"ps", "-AH"};
* String sOut;
* String sErr;
* ProcessRunner runner;
* runner = new ProcessRunner (cmd);
* runner.start ();
* runner.BlockUntilFinished ();
* sOut = runner.GetStdOutText ();
* sErr = runner.GetStdErrText ();
* System.out.println ("Stdout:");
* System.out.println (sOut);
* System.out.println ("------------------------------------------------------");
* System.out.println ("Stderr:");
* System.out.println (sErr);
* </pre>
public class ProcessRunner extends Thread
private String [] command;
private int execResult;
private String stdOutText;
private String stdErrText;
private boolean isFinished;
public ProcessRunner (String [] cmd)
command = cmd;
execResult = 0;
stdOutText = null;
stdErrText = null;
isFinished = false;
public int GetResult ()
return execResult;
public String GetStdOutText ()
return stdOutText;
public String GetStdErrText ()
return stdErrText;
public boolean IsFinished ()
return isFinished;
public void BlockUntilFinished ()
while (! isFinished)
try {Thread.sleep (250);} catch (InterruptedException e) {}
public void run ()
Process proc;
Runtime rt;
InputStream stdOut;
InputStream stdErr;
CharStream stdOutEx;
CharStream stdErrEx;
int res;
isFinished = false;
try
res = 0;
rt = Runtime.getRuntime ; ();
proc = rt.exec ; (command);
stdOut = proc.getInputStream ; ();
stdErr = proc.getErrorStream ; ();
stdOutEx = new CharStream (stdOut);
stdErrEx = new CharStream (stdErr);
stdOutEx.start ();
stdErrEx.start ();
try {res = proc.waitFor ();} catch (InterruptedException e) {}
// Process has finished; now wait until any buffers are empty.
stdOutEx.BlockUntilFinished ();
stdErrEx.BlockUntilFinished ();
stdOutText = stdOutEx.GetResult ();
stdErrText = stdErrEx.GetResult ();
execResult = res;
catch (IOException e)
isFinished = true;
throw new ExtractionException (e.getLocalizedMessage());
isFinished = true;
Class: CharStream
package rtimeexec;
import java.io.IOException;
import java.io.InputStream;
* A Character extractor. Extracts characters from a stream and puts them
* into a String. To protect from memory overflow we put a limit in place.
* When storage demads exceed that limit, an exception is thrown.
public class CharStream extends Thread
private static final int maxChunkLen = 8192;
private static final int maxStorageSize = 512 * 1024; // 512 KBytes
private InputStream sourceStream;
private StringBuffer extracted;
private boolean isFinished;
public CharStream (InputStream istream)
sourceStream = istream;
extracted = new StringBuffer ();
isFinished = false;
public String GetResult ()
String ret;
ret = extracted.toString ();
return ret;
public void BlockUntilFinished ()
while (! isFinished)
SleepThread (250);
public void run ()
byte [] buffer;
int nBytesRead;
byte b;
char c;
int iChar;
int nCharsTotal;
boolean isEOF;
isEOF = false;
nCharsTotal = 0;
isFinished = false;
while (! isEOF)
try
buffer = new byte [maxChunkLen];
nBytesRead = sourceStream.read (buffer);
if (nBytesRead >= 1)
{ // much faster stream extraction method than when we use
// BufferedReader(new InputStreamReader(sourceStream)).
for (iChar = 0; iChar < nBytesRead; iChar++)
nCharsTotal++;
if (nCharsTotal > maxStorageSize)
throw new StoreFullException
"Storage limit exceeded (" + Integer.toString (maxChunkLen) + "Bytes)"
b = buffer [iChar];
c = (char) b;
extracted.append (c);
else if (nBytesRead <= -1)
isEOF = true;
catch (IOException e)
isFinished = true;
throw new ExtractionException (e.getLocalizedMessage());
SleepThread (250);
isFinished = true;
private void SleepThread (int mSec)
try
Thread.sleep (mSec);
catch (InterruptedException e)
Class: StoreFullException
package rtimeexec;
* Exception that gets thrown when a storage container is full.
public class StoreFullException extends RuntimeException
private static final long serialVersionUID = - 4996246591135389009L;
public StoreFullException (String message)
super (message);
Class: ExtractionException
package rtimeexec;
* Thrown when there was some problem during stream extraction.
public class ExtractionException extends RuntimeException
private static final long serialVersionUID = - 6124525536783450209L;
public ExtractionException (String message)
super (message);
} -
FTP using Runtime class ...Please Help ??
Hi,
I am trying to ftp a file programatically.
I am trying to use Runtime class but facing problems
in it.This is what I am trying to do :
Runtime rr = Runtime.getRuntime();
String[] cmds = new String[2];
cmds[0]="username=rahmed";
cmds[1]="password=prpas";
try{
Process p = rr.exec("ftp 192.168.1.18",cmds);
rr.exec("put vv.txt");
This does not work ??
Is there any way to make it work ? Or is there any
other way to ftp a file programatically ??
Thanks in adavance..
Regards
RaisUnder Linux/Unix at least, it is good to use the switches -n and -i with the ftp client acually meant for intercative usage.
-i Turns off interactive prompting during multiple file transfers.
-n Restrains ftp from attempting ``auto-login'' upon initial connection.
I do "user <myuser> <mypassword>" then from the script.
I am happily using ftp this way from shell-scripts in my projects.
scp is however better than ftp: it does not send plain text passwords over the net, it support key-based login, its encrypts the data. -
Issue regarding creating a process using Runtime in Windows 2003.
Hi all..
I need to resolve a small issue related to execute an external program using runtime execution method. But when i deploy the code in websphere application server 6.1V in windows 2003 server operating system, it is starting a process with min priority and not executing even i specified waitfor method.
The code is like below.
try{
Process p = Runtime.getRuntime().exec("C:\\CopyImages.exe "+toWrite);
int ep = p.waitFor();
System.out.println("process "+ep);
catch(Exception e)
e.printStackTrace();
Please help me in resolving this issue. The above code is working in my IDE which is in Window XP but when i port it in application server in windows2003 i'm getting this issue.hi..
it is a typo error. i've given the slashes with that.
but still getting the problem. -
Using Runtime exec() method to run java files and return runtime errors
Hi
I'm writing a java editor and I use
Runtime.getRuntime().exec(command)
to compile the java files. That works fine and I deal with the returned errors using the getErrorStream().
My questions are:
1. Can I use the same technique for returning runtime errors. In any posts I've read the process runs from begining to end, returning the errors after completion. How do I return the errors of the app as they happen interactively?
2. If i cant use the exec and getErrorStream() methods then does anyone know how it is done?
Thanks in advance for any help!Read this:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
MOD -
How to capture output of java files using Runtime.exec
Hi guys,
I'm trying to capture output of java files using Runtime.exec but I don't know how. I keep receiving error message "java.lang.NoClassDefFoundError:" but I don't know how to :(
import java.io.*;
public class CmdExec {
public CmdExec() {
public static void main(String argv[]){
try {
String line;
Runtime rt = Runtime.getRuntime();
String[] cmd = new String[2];
cmd[0] = "javac";
cmd[1] = "I:\\My Documents\\My file\\CSM\\CSM00\\SmartQ\\src\\E.java";
Process proc = rt.exec(cmd);
cmd = new String[2];
cmd[0] = "javac";
cmd[1] = "I:\\My Documents\\My file\\CSM\\CSM00\\SmartQ\\src\\E";
proc = rt.exec(cmd);
//BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader input = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
while ((line = input.readLine()) != null) {
System.out.println(line);
input.close();
catch (Exception err) {
err.printStackTrace();
public class E {
public static void main(String[] args) {
System.out.println("hello world!!!!");
}Please help :)Javapedia: Classpath
How Classes are Found
Setting the class path (Windows)
Setting the class path (Solaris/Linux)
Understanding the Java ClassLoader
java -cp .;<any other directories or jars> YourClassNameYou get a NoClassDefFoundError message because the JVM (Java Virtual Machine) can't find your class. The way to remedy this is to ensure that your class is included in the classpath. The example assumes that you are in the same directory as the class you're trying to run.
javac -classpath .;<any additional jar files or directories> YourClassName.javaYou get a "cannot resolve symbol" message because the compiler can't find your class. The way to remedy this is to ensure that your class is included in the classpath. The example assumes that you are in the same directory as the class you're trying to run. -
How can i upload a image file to server by using jsp or servlet.
Hi,
I m gurumoorthy. how can i upload a image file to server by using jsp or servlet without using third party API. pls anyone send me atleast outline of the source code.
Pls send me anyone.
Regards,
Gurumoorthy.I'm not an applet programmer so I can't give you much advice there.
If you want to stream the file from the server before it's entirely uploaded, then I don't believe you can treat it like a normal file. If you're just wanting to throw it up there and then listen to it, then you can treat it like a normal file.
But again, I'm not entirely certain. You might be able to stream the start of the file from the server while you're still uploading the end of it, but it probably depends on what method you're using to do the transfer. -
How to use Runtime.getRuntime().exec() in JSP? is it works in JSP or not
Hi to all,
i want run a .exe file from JSP file. In java i am able do this, using Runtime.getRuntime().exec().
but same thing, when i trying with JSP it is not working?
plz let me is there any other ways to do it..It depends, usually (ie in an J2EE container) you're not allowed to access files or the runtime environment, by definition. What do you wan't to achieve with the exe?
--olaf -
Need a good charting library (for use in a servlet/jsp environment)
Anyone know of a good charting library for use in a servlet/jsp environment.
Use JFreechart combined with cewolf.
www.object-refinery.com/jfreechart/
To use charts in a jsp page you can use cewolf ( a taglib) based on jfreechart.
http://cewolf.sourceforge.net/
Both are free. -
Hi
i was trying to do some example with JNI. I can use JNI with standalone Java application but I just cannot figure out how I can use JNI with Servlet.
Can some one show me a sample code using JNI with Servlets.
thanks very muchhi,
I am also facing the same problem,
when I am using JNI with stand alone application it works fine but when i tried to use it with a servlet It gives unsatisfied linker error
stack: java.lang.UnsatisfiedLinkError: createSocket
at RelayConnector.createSocket(Native Method)
at RelayServlet.doGet(RelayServlet.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.iplanet.server.http.servlet.NSServletRunner.invokeServletService(NSServletRunner.java:891)
at com.iplanet.server.http.servlet.NSServletRunner.Service(NSServletRunner.java:458)
It seems i have to do some path settings in my iplenet web server.
If some one have faced the problem i would be glad to know the solution for this, i am literally bugged up,.... -
Spawn a java process using runtime.exec() method
Hi,
This is my first post in this forum. I have a small problem. I am trying to spawn a java process using Runtime.getRuntime().exec() method in Solaris. However, there is no result in this check the follwoing program.
/* Program Starts here */
import java.io.*;
public class Test {
public static void main(String args[]) {
String cmd[] = {"java", "-version"};
Runtime runtime = Runtime.getRuntime();
try{
Process proc = runtime.exec(cmd);
}catch(Exception ioException){
ioException.printStackTrace();
/* Program ends here */
There is neither any exception nor any result.
The result I am expecting is it should print the following:
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)
Please help me out in this regard
Thanks in advance
Chotu.Yes your right. It is proc.getInputStream() or proc.getErrorStream(). That is what I get for trying to use my memory instead of looking it up. Though hopefully the OP would have seen the return type of the other methods and figured it out.
Maybe you are looking for
-
Display a variable d'user exit as text in the title of a colomn
Hi, experts, I would like to calculate the number of days of a certain month. This calculation would be done in the user exit. Then in the report, this number will be displayed in the title of the colomn. Is it possible to realise this requirement an
-
Transmitting start/stop/play messages to external instruments
How do I get Logic to transmit start/stop/play messages to my external Roland groovebox? I've tried ticking the "Transmit MMC" in the Synchronization settings but it doesn't seem to work. Basically what I'm trying to achieve is when I hit play on the
-
How do i sort photos by rating stars in bridge?
ow
-
Is it possible to attach two 27 inch displays the new generation 17 inch MacPro?
Is it possible to attach two 24 inch displays to the new generation 17 inch Macbook Pro?
-
" ')' expected error..........
i have defined a function, and the compiler is giving me "')' expected " error... here is my code package ab; import java.io.*; import java.util.*; import com.db4o.Db4o; import com.db4o.ObjectContainer; import com.db4o.ObjectSet; public class Test3 e