初始化进程时出现java.io.IOexception

Question

When I compile this code, I get a java.io.IOexception error when initializing process p. However, if I were to put it in a try catch block, I would get an error saying that this varible can't be found, when I try to use it on the line below. Is there a way around the try catch block?

I am trying to run an executable file, that takes a par file as a parameter, and save the output of that executable file to a txt file.

import java.io.*;
import java.util.*;

public class Class{
public static void main (String[] args)
 {

 ProcessBuilder pb = new ProcessBuilder("C:\\....\\c.exe",    "C:\\.....\\w.par");

Process p = pb.start();

BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

Answer 1

If you try to initialize a variable in a try-catch block it will not be "found" outside the scope of the try-catch block. Modify to look like this:

 import java.io.*;
 import java.util.*;

 public class Class{

     public static void main (String[] args) {
     ProcessBuilder pb = null;
     Process p = null;

     try {
     ProcessBuilder pb = new ProcessBuilder("C:\\....\\c.exe", "C:\\.....\\w.par");

     Process p = pb.start();

     BufferedReader stdInput = new BufferedReader(newInputStreamReader(p.getInputStream()));
     } catch (IOException | ProcessException e) {
         System.err.println("Some error message"); 
     }