How to run Unix shell script from Java code?

Question

You should really look at Process Builder. It is really built for this kind of thing.

ProcessBuilder pb = new ProcessBuilder("myshellScript.sh", "myArg1", "myArg2");
 Map<String, String> env = pb.environment();
 env.put("VAR1", "myValue");
 env.remove("OTHERVAR");
 env.put("VAR2", env.get("VAR1") + "suffix");
 pb.directory(new File("myDir"));
 Process p = pb.start();

You can use Apache Commons exec library also.

Example :

package testShellScript;

import java.io.IOException;
import org.apache.commons.exec.CommandLine;
import org.apache.commons.exec.DefaultExecutor;
import org.apache.commons.exec.ExecuteException;

public class TestScript {
    int iExitValue;
    String sCommandString;

    public void runScript(String command){
        sCommandString = command;
        CommandLine oCmdLine = CommandLine.parse(sCommandString);
        DefaultExecutor oDefaultExecutor = new DefaultExecutor();
        oDefaultExecutor.setExitValue(0);
        try {
            iExitValue = oDefaultExecutor.execute(oCmdLine);
        } catch (ExecuteException e) {
            System.err.println("Execution failed.");
            e.printStackTrace();
        } catch (IOException e) {
            System.err.println("permission denied.");
            e.printStackTrace();
        }
    }

    public static void main(String args[]){
        TestScript testScript = new TestScript();
        testScript.runScript("sh /root/Desktop/testScript.sh");
    }
}

For further reference, An example is given on Apache Doc also.

I would say that it is not in the spirit of Java to run a shell script from Java. Java is meant to be cross platform, and running a shell script would limit its use to just UNIX.

With that said, it's definitely possible to run a shell script from within Java. You'd use exactly the same syntax you listed (I haven't tried it myself, but try executing the shell script directly, and if that doesn't work, execute the shell itself, passing the script in as a command line parameter).

I think you have answered your own question with

Runtime.getRuntime().exec(myShellScript);

As to whether it is good practice... what are you trying to do with a shell script that you cannot do with Java?

Yes it is possible to do so. This worked out for me.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.omg.CORBA.portable.InputStream;

public static void readBashScript() {
        try {
            Process proc = Runtime.getRuntime().exec("/home/destino/workspace/JavaProject/listing.sh /"); //Whatever you want to execute
            BufferedReader read = new BufferedReader(new InputStreamReader(
                    proc.getInputStream()));
            try {
                proc.waitFor();
            } catch (InterruptedException e) {
                System.out.println(e.getMessage());
            }
            while (read.ready()) {
                System.out.println(read.readLine());
            }
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }

Here is my example. Hope it make sense.

public static void excuteCommand(String filePath) throws IOException{
    File file = new File(filePath);
    if(!file.isFile()){
        throw new IllegalArgumentException("The file " + filePath + " does not exist");
    }
    if(isLinux()){
        Runtime.getRuntime().exec(new String[] {"/bin/sh", "-c", filePath}, null);
    }else if(isWindows()){
        Runtime.getRuntime().exec("cmd /c start " + filePath);
    }
}
public static boolean isLinux(){
    String os = System.getProperty("os.name");  
    return os.toLowerCase().indexOf("linux") >= 0;
}

public static boolean isWindows(){
    String os = System.getProperty("os.name");
    return os.toLowerCase().indexOf("windows") >= 0;
}

Yes, it is possible and you have answered it! About good practises, I think it is better to launch commands from files and not directly from your code. So you have to make Java execute the list of commands (or one command) in an existing .bat, .sh , .ksh ... files. Here is an example of executing a list of commands in a file MyFile.sh:

    String[] cmd = { "sh", "MyFile.sh", "\pathOfTheFile"};
    Runtime.getRuntime().exec(cmd);