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Listing virtual disks in Java

Is there a way to list all virtual disks attached using Java?
I've tried using ProccessBuilder to open diskpart and running command and then using InputStreamReader, save lines into an array to later extract vhd name. But after running diskpart command my program freezes.
try {
commands.add("cmd.exe");
commands.add("start");
commands.add("diskpart");
commands.add("list vdisk");
ProcessBuilder builder = new ProcessBuilder(commands);
Process p = builder.start();
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
System.out.println(line);
}
br = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while ((line = br.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}

Open ffplay & execute command with ProcessBuilder not working

I was tried to use ProcessBuilder for open ffplay.exe and execute command into ffplay. However it is unsuccessful. How could I do that?
Code:
ProcessBuilder pb = new ProcessBuilder();
pb.command("C:\\Windows\\System32\\cmd.exe", "/c",
"C:\\ffmpeg\\bin\\ffplay.exe", "tcp://192.168.1.1:5555");
pb.start();

Try using Runtime.getRuntime().exec() and doing like this :-
String[] command = {"ffplay.exe", "tcp://192.168.1.1:5555"}; // add in String array in sequence, the commands to execute
Process process = Runtime.getRuntime().exec(String[] options, null, new File("C:\\ffmpeg\\bin"));
int returnVal = process.waitFor(); // should return 0 for correct execution
try {
final BufferedReader reader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
System.out.println(line); //check for the inputstream & see the output here
}
reader.close();
} catch (final Exception e) {
e.printStackTrace();
}

Get the output from executed commands through android app

I'm performing the following code to execute linux commands in my android application that I'm creating:
public void RunAsRoot(String[] cmds){
Process p = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(p.getOutputStream());
for (String tmpCmd : cmds) {
os.writeBytes(tmpCmd+"\n");
}
os.writeBytes("exit\n");
os.flush();
}
I want to know if there is a way to know what the command is returning after it is executing. for example, if I do "ls" I would like to see what the command wold normally output.

try this code :
try {
Process process = Runtime.getRuntime().exec("ls");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder result=new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
result.append(line);
}
TextView tv = (TextView)findViewById(R.id.textView1);
tv.setText(result.toString());
}
catch (IOException e) {}

Let's go by a "String function" example
String shell_exec(String s)
{
String line="",output="";
try
{
Process p=Runtime.getRuntime().exec(new String[]{"sh","-c",s});
BufferedReader b=new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line=b.readLine())!=null){output+=line+"\r\n";}
}catch(Exception e){return "error";}
return output;
}
Now just use it:
String s=shell_exec("ls /data/data/com.mycompany.myapp");

Java InputStream to string

in my java program, i am trying to get the InputStream from a process and print it with this piece of code:
try {
Process p = Runtime.getRuntime().exec("cmd /c start dammage\\4.simulation.cmd");
//BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
//StringBuffer sb = new StringBuffer();
//String line;
//while ((line = br.readLine()) != null) {
//sb.append(line).append("\n");
//}
//System.out.println(sb.toString());
String input = IOUtils.toString(p.getErrorStream());
System.out.println(input);
} catch (IOException ex) {
Logger.getLogger(UI.class.getName()).log(Level.SEVERE, null, ex);
JOptionPane.showMessageDialog(this, "Something happened");
}
I tried both ways shown above (commented and uncommented), but none of them prints anything. So i would like to ask what am i doing wrong here?
I appreciate any help.

The buffered reader solution looks fine. You might be looking in the wrong stream. Try getting from both streams.. Like
BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
StringBuffer sb = new StringBuffer();
String line;
//Read the output from the command
while ((line = stdInput.readLine()) != null) {
sb.append(line).append("\n");
}
//read any errors from the attempted command
while ((line = stdError.readLine()) != null) {
sb.append(line).append("\n");
}

Are you sure it should print something? Because, the commented code should work just right provided the command executed is returning non-empty input stream. Try replacing the argument of exec to "cmd". And see if it's able to read from the input stream. Do following. On windows machine it should give you welcome message from cmd (the usual welcome message we get after we run start command prompt).
Process p = Runtime.getRuntime().exec("cmd");
About the uncommented code, How IOUtils work? Does it read from the error stream repeatedly. Because, IMO, it's just one time read and not the repetitive one.
Hope I don't confuse.

You should add a p.waitFor(); to give the program time to terminate. Also, verify if you really want to read stdout or stderr
This works for me:
Process p = Runtime.getRuntime().exec("cmd /c java -version");
int ret = p.waitFor();
System.out.println("process terminated with return code: " + ret);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getErrorStream()));
StringBuffer sb = new StringBuffer();
String line;
while((line = br.readLine()) != null) {
sb.append(line).append("\n");
}
System.out.println(sb.toString());

Using PrintWriter in Java

I trying to run multiple command shells from Java. I am able to do that (and get the output in the console using PrintWriter). However, I want to be able to get the output of each command in a separate String. Is that possible?
Here is a part of the code :
File wd = new File("/bin");
Process proc = null;
BufferedReader in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(proc.getOutputStream())), true);
out.println("cd ..");
out.println("ls");
System.out.println("moving to /var directory");
out.println("cd /var/");
out.println("ls");
//get output of ls command in string variable
out.println("cd ..");
out.println("cd /etc/");
out.println("ls -a");
out.println("ps");
out.println("exit");
try {
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
proc.waitFor();
in.close();
out.close();
proc.destroy();
}
catch (Exception e) {
e.printStackTrace();
}

Have you tried putting a section like
StringBuilder builder = new StringBuilder();
String line = null;
while ((line = in.readLine()) != null) {
builder.append(line).append("\n");
}
String commandOutput = builder.toString();
after each command? Is that roughly what you are trying to achieve?