Fix bug in HexString. Increase test coverage for it

src/main/java/org/openflow/util/HexString.java

@@ -17,6 +17,8 @@
 
 package org.openflow.util;
 
+import java.math.BigInteger;
+
 public class HexString {
     /**
      * Convert a string of bytes to a ':' separated hex string
@@ -76,7 +78,11 @@ public class HexString {
     }
     
     public static long toLong(String values) throws NumberFormatException {
-        return Long.parseLong(values.replaceAll(":", ""),16);
+        // Long.parseLong() can't handle HexStrings with MSB set. Sigh. 
+        BigInteger bi = new BigInteger(values.replaceAll(":", ""),16);
+        if (bi.bitLength() > 64) 
+            throw new NumberFormatException("Input string too big to fit in long: " + values);
+        return bi.longValue();
     }
 
 }

src/test/java/org/openflow/util/HexStringTest.java

@@ -17,6 +17,8 @@
 
 package org.openflow.util;
 
+import org.junit.Test;
+
 import junit.framework.TestCase;
 
 /**
@@ -27,18 +29,60 @@ import junit.framework.TestCase;
  */
 
 public class HexStringTest extends TestCase {
-
+    
+    @Test
     public void testMarshalling() throws Exception {
         String dpidStr = "00:00:00:23:20:2d:16:71";
         long dpid = HexString.toLong(dpidStr);
         String testStr = HexString.toHexString(dpid);
         TestCase.assertEquals(dpidStr, testStr);
     }
+    
+    @Test
+    public void testToLong() {
+        String dpidStr = "3e:1f:01:fc:72:8c:63:31";
+        long valid = 0x3e1f01fc728c6331L;
+        long testLong = HexString.toLong(dpidStr);
+        TestCase.assertEquals(valid, testLong);
+    }
+    
+    @Test
+    public void testToLongMSB() {
+        String dpidStr = "ca:7c:5e:d1:64:7a:95:9b";
+        long valid = -3856102927509056101L;
+        long testLong = HexString.toLong(dpidStr);
+        TestCase.assertEquals(valid, testLong);
+    }
+    
+    @Test
+    public void testToLongError() {
+        String dpidStr = "09:08:07:06:05:04:03:02:01";
+        try {
+            HexString.toLong(dpidStr);
+            fail("HexString.toLong() should have thrown a NumberFormatException");
+        }
+        catch (NumberFormatException expected) {
+            // do nothing
+        }
+    }
 
+    @Test
     public void testToStringBytes() {
         byte[] dpid = { 0, 0, 0, 0, 0, 0, 0, -1 };
         String valid = "00:00:00:00:00:00:00:ff";
         String testString = HexString.toHexString(dpid);
         TestCase.assertEquals(valid, testString);
     }
+    
+    @Test
+    public void testFromHexStringError() {
+        String invalidStr = "00:00:00:00:00:00:ffff";
+        try {
+            HexString.fromHexString(invalidStr);
+            fail("HexString.fromHexString() should have thrown a NumberFormatException");
+        }
+        catch (NumberFormatException expected) {
+            // do nothing
+        }
+    }
 }