Forgotten exception and another format of calling minizinc.

src/inport/ConversionException.java

-package inport;
-
-public class ConversionException extends Exception {
-    ConversionException(String mess) {
-        super(mess);
-    }
-}

src/inport/Main.java

@@ -51,22 +51,18 @@ public class Main {
 
                     long start = System.currentTimeMillis();
 
-                    Process p = Runtime.getRuntime().exec("minizinc --solver Chuffed " + constraints + " " + minizincData);
-                    p.waitFor();
+                    ProcessBuilder pb = new ProcessBuilder("minizinc",
+                                                                        "--solver", "Chuffed",
+                                                                        constraints, minizincData,
+                                                                        "-o", solverResults);
+                    Process process = pb.start();
+                    int exitCode = process.waitFor();
+                    assert exitCode == 0;
 
                     long finish = System.currentTimeMillis();
 
                     System.out.println((finish - start) + " milliseconds");
 
-                    try (FileWriter res = new FileWriter(solverResults)) {
-                        BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
-
-                        String line;
-                        while ((line = reader.readLine()) != null) {
-                            res.write(line + "\n");
-                        }
-                    }
-
                     ConversionUtil.resolveMiniZincResults(task, solverResults);
                     task.serialize(fileName);
                 } catch (IOException | InterruptedException ex) {