Running Command Line in Java [duplicate] - java

This question already has answers here:
Executing a Java application in a separate process
(9 answers)
Closed 7 years ago.
Is there a way to run this command line within a Java application?
java -jar map.jar time.rel test.txt debug
I can run it with command but I couldn't do it within Java.

Runtime rt = Runtime.getRuntime();
Process pr = rt.exec("java -jar map.jar time.rel test.txt debug");
http://docs.oracle.com/javase/7/docs/api/java/lang/Runtime.html

You can also watch the output like this:
final Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");
new Thread(new Runnable() {
public void run() {
BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
try {
while ((line = input.readLine()) != null)
System.out.println(line);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
p.waitFor();
And don't forget, if you are running a windows command, you need to put cmd /c in front of your command.
EDIT: And for bonus points, you can also use ProcessBuilder to pass input to a program:
String[] command = new String[] {
"choice",
"/C",
"YN",
"/M",
"\"Press Y if you're cool\""
};
String inputLine = "Y";
ProcessBuilder pb = new ProcessBuilder(command);
pb.redirectErrorStream(true);
Process p = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
writer.write(inputLine);
writer.newLine();
writer.close();
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
This will run the windows command choice /C YN /M "Press Y if you're cool" and respond with a Y. So, the output will be:
Press Y if you're cool [Y,N]?Y

To avoid the called process to be blocked if it outputs a lot of data on the standard output and/or error, you have to use the solution provided by Craigo. Note also that ProcessBuilder is better than Runtime.getRuntime().exec(). This is for a couple of reasons: it tokenizes better the arguments, and it also takes care of the error standard output (check also here).
ProcessBuilder builder = new ProcessBuilder("cmd", "arg1", ...);
builder.redirectErrorStream(true);
final Process process = builder.start();
// Watch the process
watch(process);
I use a new function "watch" to gather this data in a new thread. This thread will finish in the calling process when the called process ends.
private static void watch(final Process process) {
new Thread() {
public void run() {
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = null;
try {
while ((line = input.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
}

Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

import java.io.*;
Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");
Consider the following if you run into any further problems, but I'm guessing that the above will work for you:
Problems with Runtime.exec()

what about
public class CmdExec {
public static Scanner s = null;
public static void main(String[] args) throws InterruptedException, IOException {
s = new Scanner(System.in);
System.out.print("$ ");
String cmd = s.nextLine();
final Process p = Runtime.getRuntime().exec(cmd);
new Thread(new Runnable() {
public void run() {
BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
try {
while ((line = input.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
p.waitFor();
}
}

Have you tried the exec command within the Runtime class?
Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug")
Runtime - Java Documentation

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Related

Calling "mysqldump" with Runtime.getRuntime().exec(cmd) from Windows 7

I am trying to dump a MySQL database within my Java application the following way:
String[] command = new String[] {"cmd.exe", "/c", "C:/mysql/mysqldump.exe" --quick --lock-tables --user=\"root\" --password=\"mypwd\" mydatabase > \"C:/mydump.sql\""};
Process process = Runtime.getRuntime().exec(command);
int exitcode = process.waitFor();
The process fails with exit-code 6. I somewhere read that the operand ">" is not correctly interpreted and there was the hint to use "cmd.exe /c" as prefix. But it still doesn't work.
Any ideas?
Yes, you are right , some days ago I made class for exporting DataBase from MySQL...
You coud read output sream from console and then write to file
String[] command = new String[] {"cmd.exe", "/c", "\"C:/Program Files/MySQL/MySQL Server 5.6/bin/mysqldump.exe\" --quick --lock-tables --user=\"root\" --password=\"mypwd\" mydatabase "};
Process process = Runtime.getRuntime().exec(command);
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
while ((line = input.readLine()) != null) {
System.out.println(line); //there you can write file
}
input.close();
Best Regards
Okay here's the final solution. You need to put the "process-reader to file-writer" code into a separate thread and finally wait for the process object to be finished:
// define backup file
File fbackup = new File("C:/backup.sql");
// execute mysqldump command
String[] command = new String[] {"cmd.exe", "/c", "C:/path/to/mysqldump.exe --quick --lock-tables --user=myuser --password=mypwd mydatabase"};
final Process process = Runtime.getRuntime().exec(command);
// write process output line by line to file
if(process!=null) {
new Thread(new Runnable() {
#Override
public void run() {
try{
try(BufferedReader reader = new BufferedReader(new InputStreamReader(new DataInputStream(process.getInputStream())));
BufferedWriter writer = new BufferedWriter(new FileWriter(fbackup))) {
String line;
while((line=reader.readLine())!=null) {
writer.write(line);
writer.newLine();
}
}
} catch(Exception ex){
// handle or log exception ...
}
}
}).start();
}
if(process!=null && process.waitFor()==0) {
// success ...
} else {
// failed
}
On Linux you can directly re-direct the output of the command to a file by using ">" as usual... (and also on Mac OS X I think). So no need for the thread. Generally, please avoid white spaces in your path to the mysqldump/mysqldump.exe file!

Not able to capture output of "who -m" command in JAVA

I want to get the IP address of logged in user of the telnet session
So I have written the following code:
Process p1 = Runtime.getRuntime().exec(new String[] {"/usr/bin/who", "-m"});
p1.waitFor();
BufferedReader reader = new BufferedReader(new InputStreamReader(p1.getInputStream()));
String line = reader.readLine();
System.out.println("line=" + line);
reader.close();
But I am getting the output as "null".
Where as expected output is:
linus pts/1 Dec 10 03:48 (172.21.235.48)
In this case you shouldn't pass the -m option.
This works for me :
Process p1 = Runtime.getRuntime().exec(new String[] {"/usr/bin/who"});
Try to consume the input stream from the process before calling waitFor().
You can create a shell script which will receive parameter (option) from your java program.
Then you can run your shell script from java like this -
ProcessBuilder pb = new ProcessBuilder("/PATH/test.sh","-m");
String line;
Process process=pb.start();
java.io.InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
while ((line = br.readLine()) != null)
{
System.out.println(line);
}
return br;
Now in test.sh, you cab grab the argument and run the command -
/usr/bin/who $1 (needs to check, not sure)
Hope this helps.
Thanks guys for the replies.
From the reply of "dystroy" I understood that -m was creating problem.
I tried --m and it worked :)
Please try this code. It's working for me and returns the same output as who -m UNIX command.
import java.io.*;
public class UserPB
{
public static void main(String[] args)
{
try {
// ProcessBuilder pb = new ProcessBuilder("/u01/app/chdir/user.sh");
ProcessBuilder pb = new ProcessBuilder("who");
Process p;
p = pb.start();
BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
System.out.println("Your Host Details--->"+input.readLine());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

Run processbuilder and get in and output

I'm trying to get my program to launch Enchanter to SSH into my server, but can't seem to figure out how to get in and output to go to stdin and stdout, or anywhere for that matter. I just get a blank output window in Netbeans. How to I get the Jar to run, and get input/output?
public class openShell {
public void openShell() throws IOException {
String line;
Scanner scan = new Scanner(System.in);
ProcessBuilder builder = new ProcessBuilder ("C:\\Program Files\\Java\\lib\\enchanter-beanshell-0.6.jar", "myscript.bsh");
builder.redirectErrorStream(true);
Process process = builder.start();
OutputStream stdin = process.getOutputStream ();
InputStream stderr = process.getErrorStream ();
InputStream stdout = process.getInputStream ();
BufferedReader reader = new BufferedReader (new InputStreamReader(stdout));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(stdin));
while (scan.hasNext()) {
String input = scan.nextLine();
if (input.trim().equals("exit")) {
// Putting 'exit' amongst the echo --EOF--s below doesn't work.
writer.write("exit\n");
} else {
writer.write("((" + input + ") && echo --EOF--) || echo --EOF--\n");
}
writer.flush();
line = reader.readLine();
while (line != null && ! line.trim().equals("--EOF--")) {
System.out.println ("Stdout: " + line);
line = reader.readLine();
}
if (line == null) {
break;
}
}
}
}
private void LaunchButtonActionPerformed(ActionEvent evt) {
//openShell open = new openShell(); //RUNS BUT NO IN OR OUTPUT
//BELOW CODE IS FOR TESTING, JUST TRYING TO GET PROCESSBUILDER TO CONNECT
// TO MY JAR
try {
ProcessBuilder builder = new ProcessBuilder(
"Java -jar C:\\Program Files\\Java\\lib\\enchanter-beanshell-0.6.jar");
builder.redirectErrorStream(true);
Process process = builder.start();
} catch (IOException ex) {
Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
}
}
The method ProcessBuilder.inheritIO will redirect your command streams in your stdin, stdout and stderr. This applies to Java 7.
String[] args = {
"java",
"-jar",
"C:\\Program Files\\Java\\lib\\enchanter-beanshell-0.6.jar"
};
ProcessBuilder builder = new ProcessBuilder(args);
Start with breaking up the arguments as above. Then implement all the recommendations of When Runtime.exec() won't.
The methods Process.getInputStream and Process.getOutputStream will get you streams that you can then read from and write to.

How to Execute Windows Commands Using Java - Change Network Settings

In Java, I want to be able to execute a Windows command.
The command in question is netsh. This will enable me to set/reset my IP address.
Note that I do not want to execute a batch file.
Instead of using a batch file, I want to execute such commands directly. Is this possible?
Here is my implemented Solution for Future Reference:
public class JavaRunCommand {
private static final String CMD =
"netsh int ip set address name = \"Local Area Connection\" source = static addr = 192.168.222.3 mask = 255.255.255.0";
public static void main(String args[]) {
try {
// Run "netsh" Windows command
Process process = Runtime.getRuntime().exec(CMD);
// Get input streams
BufferedReader stdInput = new BufferedReader(new InputStreamReader(process.getInputStream()));
BufferedReader stdError = new BufferedReader(new InputStreamReader(process.getErrorStream()));
// Read command standard output
String s;
System.out.println("Standard output: ");
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
// Read command errors
System.out.println("Standard error: ");
while ((s = stdError.readLine()) != null) {
System.out.println(s);
}
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
}
Runtime.getRuntime().exec("netsh");
See Runtime Javadoc.
EDIT: A later answer by leet suggests that this process is now deprecated. However, as per the comment by DJViking, this appears not to be the case: Java 8 documentation. The method is not deprecated.
Use ProcessBuilder
ProcessBuilder pb=new ProcessBuilder(command);
pb.redirectErrorStream(true);
Process process=pb.start();
BufferedReader inStreamReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
while(inStreamReader.readLine() != null){
//do something with commandline output.
}
You can run the command with Runtime.getRuntime().exec("<command>") (eg. Runtime.getRuntime().exec("tree")). But, this will only run executables found in path, not commands like echo, del, ... But only stuff like tree.com, netstat.com, ... To run regular commands, you will have to put cmd /c before the command (eg Runtime.getRuntime().exec("cmd /c echo echo"))
public static void main(String[] args) {
String command="netstat";
try {
Process process = Runtime.getRuntime().exec(command);
System.out.println("the output stream is "+process.getOutputStream());
BufferedReader reader=new BufferedReader( new InputStreamReader(process.getInputStream()));
String s;
while ((s = reader.readLine()) != null){
System.out.println("The inout stream is " + s);
}
} catch (IOException e) {
e.printStackTrace();
}
}
This works.
Runtime#exec().

Run MS-DOS command from java program

How can i run MS-DOS command within my java program ?
How to run command-line or execute external application from Java:
import java.io.*;
public class Main {
public static void main(String args[]) {
try {
Runtime rt = Runtime.getRuntime();
//Process pr = rt.exec("cmd /c dir");
Process pr = rt.exec("c:\\helloworld.exe");
BufferedReader input = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line=null;
while((line=input.readLine()) != null) {
System.out.println(line);
}
int exitVal = pr.waitFor();
System.out.println("Exited with error code "+exitVal);
} catch(Exception e) {
System.out.println(e.toString());
e.printStackTrace();
}
}
}
Process p = Runtime.getRuntime().exec("cmd /C dir");
BufferedReader stdin = new BufferedReader(new InputStreamReader(p.getInputStream()));
Use a ProcessBuilder eg.
Process p = new ProcessBuilder("myCommand", "myArg").start();
This is the Java5 addition that has superseded Runtime.getRuntime().exec()
use Runtime.getRuntime().exec()

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