Unique use of System.exit to end program.

main/src/main/java/com/ongres/pgio/main/Main.java

@@ -29,7 +29,10 @@ import com.ongres.pgio.main.stats.StatSnapshot;
 import com.ongres.pgio.main.stats.serializer.CsvSerializer;
 import com.ongres.pgio.main.stats.serializer.StatSerializer;
 import com.ongres.pgio.main.version.Version;
+
 import fi.iki.elonen.NanoHTTPD;
+
+import joptsimple.OptionException;
 import joptsimple.OptionParser;
 import joptsimple.OptionSet;
 
@@ -53,19 +56,35 @@ import javax.json.JsonString;
 
 public class Main {
   public static void main(String[] args) throws Exception {
+    System.exit(run(args));
+  }
+  
+  private static int run(String[] args) throws Exception {
+    OptionParser parser;
+    OptionSet options;
+    try {
+      parser = createOptionParser();
+      options = parser.parse(args);
+    } catch (OptionException ex) {
+      System.err.println(messageOrType(ex));
+      return -1;
+    } catch (RuntimeException ex) {
+      onException(ex, true);
+      return -1;
+    } catch (Exception ex) {
+      onException(ex, true);
+      return -1;
+    }
+    
     try {
-      OptionParser parser = createOptionParser();
-      
-      OptionSet options = parser.parse(args);
-      
       if (options.has("help")) {
         parser.printHelpOn(System.out);
-        System.exit(0);
+        return 0;
       }
       
       if (options.has("version")) {
         System.out.println(Version.getVersion());
-        System.exit(0);
+        return 0;
       }
       
       Config config = configOptionSet(options);
@@ -75,21 +94,47 @@ public class Main {
       } else {
         runCollector(config);
       }
-    } catch (Throwable throwable) {
-      if (throwable.getMessage() != null) {
-        System.err.println(throwable.getMessage());
-      } else {
-        System.err.println("Seems like you hit a bug. Please open an issue with"
-            + " the following stack trace at https://gitlab.com/teoincontatto/pgio/issues/new");
-        System.err.println();
-        throwable.printStackTrace(System.err);
-        System.err.println();
-      }
-      System.err.println("Try \"pgio --help\" for more information.");
-      System.exit(1);
+    } catch (RuntimeException ex) {
+      return onException(ex, options.has("debug"));
+    } catch (Exception ex) {
+      return onException(ex, options.has("debug"));
+    }
+    
+    return 0;
+  }
+
+  private static int onException(Exception ex, boolean debug) {
+    System.err.println(messageOrType(ex));
+    
+    if (debug) {
+      onExceptionHint(ex);
     }
+    
+    return -1;
+  }
+
+  private static void onExceptionHint(Exception ex) {
+    System.err.println();
+    System.err.println();
+    System.err.println("If you think you hit a bug. Please open an issue attaching"
+        + " the following stack trace at https://gitlab.com/ongresinc/pgio/issues/new");
+    System.err.println();
+    ex.printStackTrace(System.err);
+    System.err.println();
+    System.err.println("Try \"pgio --help\" for more information.");
+    System.err.println();
   }
 
+  private static String messageOrType(Exception ex) {
+    String message = ex.getMessage();
+    
+    if (message == null) {
+      return ex.getClass().getName();
+    }
+    
+    return message;
+  }
+  
   private static void runPrometheusService(Config config) throws IOException {
     PrometheusService service = new PrometheusService(config);
     service.start(NanoHTTPD.SOCKET_READ_TIMEOUT, false);