Run cmd commands through Java
JavaCmdCdJava Problem Overview
I found several code snippets for running cmd commands through a Java class, but I wasn't able to understand it.
This is code for opening the cmd
public void excCommand(String new_dir){
Runtime rt = Runtime.getRuntime();
try {
rt.exec(new String[]{"cmd.exe","/c","start"});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
And I found some other links for adding other commands such as cd http://www.coderanch.com/t/109753/Linux-UNIX/exec-command-cd-command-java
Can anyone help me to understand how to cd a directory such as:
cd C:\Program Files\Flowella
then run other commands on that directory?
Java Solutions
Solution 1 - Java
One way to run a process from a different directory to the working directory of your Java program is to change directory and then run the process in the same command line. You can do this by getting cmd.exe to run a command line such as cd some_directory && some_program.
The following example changes to a different directory and runs dir from there. Admittedly, I could just dir that directory without needing to cd to it, but this is only an example:
import java.io.*;
public class CmdTest {
public static void main(String[] args) throws Exception {
ProcessBuilder builder = new ProcessBuilder(
"cmd.exe", "/c", "cd \"C:\\Program Files\\Microsoft SQL Server\" && dir");
builder.redirectErrorStream(true);
Process p = builder.start();
BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while (true) {
line = r.readLine();
if (line == null) { break; }
System.out.println(line);
}
}
}
Note also that I'm using a ProcessBuilder to run the command. Amongst other things, this allows me to redirect the process's standard error into its standard output, by calling redirectErrorStream(true). Doing so gives me only one stream to read from.
This gives me the following output on my machine:
C:\Users\Luke\StackOverflow>java CmdTest
Volume in drive C is Windows7
Volume Serial Number is D8F0-C934
Directory of C:\Program Files\Microsoft SQL Server
29/07/2011 11:03 <DIR> .
29/07/2011 11:03 <DIR> ..
21/01/2011 20:37 <DIR> 100
21/01/2011 20:35 <DIR> 80
21/01/2011 20:35 <DIR> 90
21/01/2011 20:39 <DIR> MSSQL10_50.SQLEXPRESS
0 File(s) 0 bytes
6 Dir(s) 209,496,424,448 bytes free
Solution 2 - Java
You can try this:-
Process p = Runtime.getRuntime().exec(command);
Solution 3 - Java
If you want to perform actions like cd, then use:
String[] command = {command_to_be_executed, arg1, arg2};
ProcessBuilder builder = new ProcessBuilder(command);
builder = builder.directory(new File("directory_location"));
Example:
String[] command = {"ls", "-al"};
ProcessBuilder builder = new ProcessBuilder(command);
builder = builder.directory(new File("/ngs/app/abc"));
Process p = builder.start();
It is important that you split the command and all arguments in separate strings of the string array (otherwise they will not be provided correctly by the ProcessBuilder API).
Solution 4 - Java
Here is a more complete implementation of command line execution.
Usage
executeCommand("ls");
Output:
12/27/2017 11:18:11:732: ls
12/27/2017 11:18:11:820: build.gradle
12/27/2017 11:18:11:820: gradle
12/27/2017 11:18:11:820: gradlew
12/27/2017 11:18:11:820: gradlew.bat
12/27/2017 11:18:11:820: out
12/27/2017 11:18:11:820: settings.gradle
12/27/2017 11:18:11:820: src
Code
private void executeCommand(String command) {
try {
log(command);
Process process = Runtime.getRuntime().exec(command);
logOutput(process.getInputStream(), "");
logOutput(process.getErrorStream(), "Error: ");
process.waitFor();
} catch (IOException | InterruptedException e) {
e.printStackTrace();
}
}
private void logOutput(InputStream inputStream, String prefix) {
new Thread(() -> {
Scanner scanner = new Scanner(inputStream, "UTF-8");
while (scanner.hasNextLine()) {
synchronized (this) {
log(prefix + scanner.nextLine());
}
}
scanner.close();
}).start();
}
private static SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss:SSS");
private synchronized void log(String message) {
System.out.println(format.format(new Date()) + ": " + message);
}
Solution 5 - Java
My example (from real project)
folder — File.
zipFile, filesString — String;
final String command = "/bin/tar -xvf " + zipFile + " " + filesString;
logger.info("Start unzipping: {} into the folder {}", command, folder.getPath());
final Runtime r = Runtime.getRuntime();
final Process p = r.exec(command, null, folder);
final int returnCode = p.waitFor();
if (logger.isWarnEnabled()) {
final BufferedReader is = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = is.readLine()) != null) {
logger.warn(line);
}
final BufferedReader is2 = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while ((line = is2.readLine()) != null) {
logger.warn(line);
}
}
Solution 6 - Java
Try this:
Process runtime = Runtime.getRuntime().exec("cmd /c start notepad++.exe");
Solution 7 - Java
The easiest way would be to use Runtime.getRuntime.exec().
For example, to get a registry value for the default browser on Windows:
String command = "REG QUERY HKEY_CLASSES_ROOT\\http\\shell\\open\\command";
try
{
Process process = Runtime.getRuntime().exec(command);
} catch (IOException e)
{
e.printStackTrace();
}
Then use a Scanner to get the output of the command, if necessary.
Scanner kb = new Scanner(process.getInputStream());
Note: the \ is an escape character in a String, and must be escaped to work properly (hence the \\).
However, there is no executable called cd, because it can't be implemented in a separate process.
The one case where the current working directory matters is executing an external process (using ProcessBuilder or Runtime.exec()). In those cases you can specify the working directory to use for the newly started process explicitly.
Easiest way for your command:
System.setProperty("user.dir", "C:\\Program Files\\Flowella");
Solution 8 - Java
Once you get the reference to Process, you can call getOutpuStream on it to get the standard input of the cmd prompt. Then you can send any command over the stream using write method as with any other stream.
Note that it is process.getOutputStream() which is connected to the stdin on the spawned process. Similarly, to get the output of any command, you will need to call getInputStream and then read over this as any other input stream.
Solution 9 - Java
public class Demo { public static void main(String args[]) throws IOException {
Process process = Runtime.getRuntime().exec("/Users/******/Library/Android/sdk/platform-tools/adb" + " shell dumpsys battery ");
BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = null;
while (true) {
line = in.readLine();
if (line == null) { break; }
System.out.println(line);
}
}
}
Solution 10 - Java
Stopping and Disabling a service can be done via below code:
static void sdService() {
String[] cmd = {"cmd.exe", "/c", "net", "stop", "MSSQLSERVER"};
try {
Process process = new ProcessBuilder(cmd).start();
process.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
line = null;
bufferedReader = null;
Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= disabled");
p.waitFor();
bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Enabling and Starting a service can be done via below code
static void esService() {
String[] cmd = {"cmd.exe", "/c", "net", "start", "MSSQLSERVER"};
try {
Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= auto");
//Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= demand");
p.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
line = null;
bufferedReader = null;
Process process = new ProcessBuilder(cmd).start();
process.waitFor();
bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Executing command from any folder can be done via below code.
static void runFromSpecificFolder() {
try {
ProcessBuilder processBuilder = new ProcessBuilder("cmd.exe", "/c", "cd \"C:\\Users\\himan\\Desktop\\Java_Test_Deployment\\jarfiles\" && dir");
//processBuilder.directory(new File("C://Users//himan//Desktop//Java_Test_Deployment//jarfiles"));
processBuilder.redirectErrorStream(true);
Process p = processBuilder.start();
p.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String args[]) {
sdService();
runFromSpecificFolder();
esService();
}
Solution 11 - Java
You can't run cd this way, because cd isn't a real program; it's a built-in part of the command-line, and all it does is change the command-line's environment. It doesn't make sense to run it in a subprocess, because then you're changing that subprocess's environment — but that subprocess closes immediately, discarding its environment.
To set the current working directory in your actual Java program, you should write:
System.setProperty("user.dir", "C:\\Program Files\\Flowella");
Solution 12 - Java
one of the way to execute cmd from java !
public void executeCmd() {
String anyCommand="your command";
try {
Process process = Runtime.getRuntime().exec("cmd /c start cmd.exe /K " + anyCommand);
} catch (IOException e) {
e.printStackTrace();
}
}
Solution 13 - Java
The simplest and shortest way is to use [CmdTool][1] library.
new Cmd()
.configuring(new WorkDir("C:/Program Files/Flowella"))
.command("cmd.exe", "/c", "start")
.execute();
You can find more examples [here][1]. [1]: https://github.com/alekseysotnikov/CmdTool
Solution 14 - Java
Here the value adder is use of ampersands to batch commands and correct format for change drive with cd.
public class CmdCommander {
public static void main(String[] args) throws Exception {
//easyway to start native windows command prompt from Intellij
/*
Rules are:
1.baseStart must be dual start
2.first command must not have &.
3.subsequent commands must be prepended with &
4.drive change needs extra &
5.use quotes at start and end of command batch
*/
String startQuote = "\"";
String endQuote = "\"";
//String baseStart_not_taking_commands = " cmd /K start ";
String baseStart = " cmd /K start cmd /K ";//dual start is must
String first_command_chcp = " chcp 1251 ";
String dirList = " &dir ";//& in front of commands after first command means enter
//change drive....to yours
String changeDir = " &cd &I: ";//extra & makes changing drive happen
String javaLaunch = " &java ";//just another command
String javaClass = " Encodes ";//parameter for java needs no &
String javaCommand = javaLaunch + javaClass;
//build batch command
String totalCommand =
baseStart +
startQuote +
first_command_chcp +
//javaCommand +
changeDir +
dirList +
endQuote;
System.out.println(totalCommand);//prints into Intellij terminal
runCmd(totalCommand);
//Thread t = Thread.currentThread();
//t.sleep(3000);
System.out.println("loppu hep");//prints into Intellij terminal
}
public static void runCmd(String command) throws Exception {
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
}
}