使用Java运行Linux命令时出现问题？

Question

I am running command using Java and getting no output.

Process p;
Runtime run = Runtime.getRuntime();  
    String s1 = "queryData 1005017 --format '\"%s" scope'";

    System.out.println("Command is " + s1);


    try {  

        p = run.exec(s1);  
        BufferedReader br = new BufferedReader(
                new InputStreamReader(p.getInputStream()));
            while ((s = br.readLine()) != null)
                System.out.println("line: " + s);
        p.getErrorStream();  
        p.waitFor();

    }  

While the same command ---> queryData 1005017 --format '"%s" scope' runs without any issue. Wondering am i missing any thing while handling either double quote, or % sign?

Answer 1

You didn't escape the internal quotes properly:

String s1 = "queryData 1005017 --format '\"%s" scope'";
            ^--start java string             ^--end java string
                                               ^^^^^ what's this mean to java?

You probably want

String s1 = "queryData 1005017 --format '\"%s\" scope'";
                                             ^--note this

instead.

Answer 2

Try do NOT use strings to start processes from Java. Correct way is usage of ProcessBuilder :

p = new ProcessBuilder(Arrays.asList(
    "queryData", "1005017", "--format", "\"%s\" scope")).start();