improve subcommand exception handling

scm-clients/scm-cli-client/src/main/java/sonia/scm/cli/I18n.java

@@ -50,6 +50,9 @@ import java.util.ResourceBundle;
 public class I18n
 {
 
+  /** Field description */
+  public static final String ERROR = "error";
+
   /** Field description */
   public static final String GROUP_NOT_FOUND = "groupNotFound";
 

scm-clients/scm-cli-client/src/main/java/sonia/scm/cli/cmd/SubCommand.java

@@ -126,9 +126,19 @@ public abstract class SubCommand
     }
     catch (CmdLineException ex)
     {
+      if (logger.isWarnEnabled())
+      {
+        logger.warn("could not parse comannd line", ex);
+      }
 
-      // todo error handling
-      logger.error("could not parse command line", ex);
+      if (!help)
+      {
+        output.append(i18n.getMessage(I18n.ERROR)).append(": ");
+        output.println(ex.getMessage());
+        output.println();
+      }
+
+      printHelp(parser);
     }
   }
 
@@ -183,6 +193,18 @@ public abstract class SubCommand
     return session;
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param parser
+   */
+  protected void printHelp(CmdLineParser parser)
+  {
+    parser.printUsage(output, i18n.getBundle());
+    System.exit(1);
+  }
+
   //~--- fields ---------------------------------------------------------------
 
   /** Field description */

scm-clients/scm-cli-client/src/main/resources/sonia/resources/i18n.properties

@@ -29,6 +29,7 @@
 
 VAL = value
 FILE = file
+error = Error
 
 subCommandsTitle = SubCommands