[FIXED HUDSON-5162] in 1.341.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@25730 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/node_monitors/AbstractDiskSpaceMonitor.java

@@ -23,6 +23,10 @@ public abstract class AbstractDiskSpaceMonitor extends NodeMonitor {
         DiskSpace.parse(threshold); // make sure it parses
     }
 
+    public AbstractDiskSpaceMonitor() {
+        this.freeSpaceThreshold = "1GB";
+    }
+
     public long getThresholdBytes() {
         if (freeSpaceThreshold==null)
             return DEFAULT_THRESHOLD; // backward compatibility with the data format that didn't have 'freeSpaceThreshold'

core/src/main/java/hudson/node_monitors/DiskSpaceMonitor.java

@@ -46,7 +46,9 @@ public class DiskSpaceMonitor extends AbstractDiskSpaceMonitor {
 	public DiskSpaceMonitor(String freeSpaceThreshold) throws ParseException {
         super(freeSpaceThreshold);
 	}
-	
+
+    public DiskSpaceMonitor() {}
+    
     public DiskSpace getFreeSpace(Computer c) {
         return DESCRIPTOR.get(c);
     }

core/src/main/java/hudson/node_monitors/TemporarySpaceMonitor.java

@@ -48,7 +48,9 @@ public class TemporarySpaceMonitor extends AbstractDiskSpaceMonitor {
 	public TemporarySpaceMonitor(String freeSpaceThreshold) throws ParseException {
         super(freeSpaceThreshold);
 	}
-	
+
+    public TemporarySpaceMonitor() {}
+
     public DiskSpace getFreeSpace(Computer c) {
         return DESCRIPTOR.get(c);
     }