Java ProcessBuilder Passing parameters

Question

I have a shell script with one parameter, as follow:

test.sh

#!/bin/bash
echo "Shell Demo";
echo "Hello $0";

Now I want to execute this script using ProgressBuilder and pass parameters. The java code as follow:

 public void testShell() throws Exception {
        String shPath = "./test.sh";
        // want to pass a value "Jack" to shell script
        ProcessBuilder builder = new ProcessBuilder(shPath, "Jack");
        Process result = builder.start();
        result.waitFor();
        BufferedReader stdInput = new BufferedReader(new InputStreamReader(result.getInputStream()));
        String output;
        while ((output = stdInput.readLine()) != null) {
            System.out.println(output);
        }
    }

Output:

Shell Demo
Hello ./test.sh

The output I want is:

Shell Demo
Hello Jack

Answer 1

You're going to want to remove that result.waitFor and also specify the executor to use, ie) bash (you can also use sh), other than that you're on the right path.

public String[] createExecutionString(String process, String...params) {
    final List<String> executor = new ArrayList<>();
    executor.add("bash"); /* cmd on windows */
    executor.add("-c"); /* /c on windows */
    executor.add(process);
    for (String param : params) {
        executor.add(param);
    }
    return executor.toArray(new String[0]);
}

public void testShell() throws Exception {
    String shPath = "./test.sh";
    // want to pass a value "Jack" to shell script
    ProcessBuilder builder = new ProcessBuilder(createExecutionString(shPath, "Jack"));
    Process result = builder.start();
    BufferedReader stdInput = new BufferedReader(new InputStreamReader(result.getInputStream()));
    String output;
    while ((output = stdInput.readLine()) != null) {
        System.out.println(output);
    }
}