From ffe3ff249ffd00c0a21edb2ccda63c720a22c9e4 Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Wed, 2 Sep 2020 18:43:38 +0200
Subject: [PATCH] specific exception

---
 .../java/de/hottis/mbusMaster/MbusMaster.java | 16 +++++++++-----
 .../de/hottis/mbusMaster/MbusgwChild.java     |  4 ++++
 .../mbusMaster/MbusgwChildException.java      | 21 +++++++++++++++++++
 3 files changed, 36 insertions(+), 5 deletions(-)
 create mode 100644 src/main/java/de/hottis/mbusMaster/MbusgwChildException.java

diff --git a/src/main/java/de/hottis/mbusMaster/MbusMaster.java b/src/main/java/de/hottis/mbusMaster/MbusMaster.java
index ad6f3e4..99af8b4 100644
--- a/src/main/java/de/hottis/mbusMaster/MbusMaster.java
+++ b/src/main/java/de/hottis/mbusMaster/MbusMaster.java
@@ -1,5 +1,7 @@
 package de.hottis.mbusMaster;
 
+import java.io.IOException;
+
 import java.util.Properties;
 
 import org.apache.logging.log4j.LogManager;
@@ -26,13 +28,17 @@ public class MbusMaster {
 		mbusgw.start();
 
 
-		mbusgw.sendRequest((byte)0x5b, (byte)80);
+		try {
+			mbusgw.sendRequest((byte)0x5b, (byte)80);
 
-		byte[] frame = mbusgw.collectResponse();
-		for (byte x : frame) {
-			System.out.print(Integer.toHexString(Byte.toUnsignedInt(x)) + " ");
+			byte[] frame = mbusgw.collectResponse();
+			for (byte x : frame) {
+				System.out.print(Integer.toHexString(Byte.toUnsignedInt(x)) + " ");
+			}
+			System.out.println();
+		} catch (IOException e) {
+			logger.error("Error in Meterbus dialog: " + e.toString() + ", " + e.getMessage());
 		}
-		System.out.println();
 
 		System.out.println("Stopping mbusgw process");
 		mbusgw.stop();
diff --git a/src/main/java/de/hottis/mbusMaster/MbusgwChild.java b/src/main/java/de/hottis/mbusMaster/MbusgwChild.java
index e35d91c..149d445 100644
--- a/src/main/java/de/hottis/mbusMaster/MbusgwChild.java
+++ b/src/main/java/de/hottis/mbusMaster/MbusgwChild.java
@@ -99,6 +99,10 @@ public class MbusgwChild {
 		int responseCode = Byte.toUnsignedInt(header[0]);
     int responseLen = Byte.toUnsignedInt(header[1]);
     logger.debug("n: " + n + ", h: " + responseCode + ", l: " + responseLen);
+    if (responseCode != 0) {
+      logger.debug("Received error from child: " + responseCode);
+      throw new MbusgwChildException("Error " + responseCode + " from child");
+    }
 		byte[] frame = new byte[responseLen];
     n = this.processInput.read(frame, 0, responseLen);
     logger.debug("frame completely read");
diff --git a/src/main/java/de/hottis/mbusMaster/MbusgwChildException.java b/src/main/java/de/hottis/mbusMaster/MbusgwChildException.java
new file mode 100644
index 0000000..d0920b6
--- /dev/null
+++ b/src/main/java/de/hottis/mbusMaster/MbusgwChildException.java
@@ -0,0 +1,21 @@
+package de.hottis.mbusMaster;
+
+import java.io.IOException;
+
+public class MbusgwChildException extends IOException {
+    public MbusgwChildException() {
+        super();
+    }
+
+    public MbusgwChildException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public MbusgwChildException(String message) {
+        super(message);
+    }
+
+    public MbusgwChildException(Throwable cause) {
+        super(cause);
+    }
+}
\ No newline at end of file