How to determine which field in a tMap is causing issues

[Anonymous]

Noob Question -- my apologies.
How do you trace mapping issues that cause java errors from a tMap down to the problematic column that is causing the issue?
I made a huge mistake and just mass corrected everything without testing each unit one by one, and now I am receiving the error on my tMap and am having a difficult time tracking the columns transformation code in the tMap to find the offending code of the 100+ column map:

Error in the component's properties!

I expanded it and saw:

Type mismatch: cannot convert from Object&Serializable&Comparable<?> to String

.. just letting the broken code continue I see:

 connecting to socket on port 4046
 connected
Exception in thread "Thread-2" java.lang.Error: Unresolved compilation problem: 
	Type mismatch: cannot convert from Object&Serializable&Comparable<?> to String
	at sap_uploads.sap_uploads_0_1.sap_uploads.tFileList_1Process(sap_uploads.java:2652)
	at sap_uploads.sap_uploads_0_1.sap_uploads$1.run(sap_uploads.java:3689)
 connecting to socket on port 4616
 connected

[Anonymous]

hi
a first step to debug is to open code (just beside designer) and look at the right if you see a red "mark" ...
click on it , and you'll see which part of your code(and the name of the column) have a problem ...
regards
laurent

[alevy]

I find this kind of compilation error usually results from a missing " to start or end a String constant. Find it using Laurent's suggestion.

[Anonymous]

perhaps in a ternary condition (boolean expression ? value1 : value2) ... but not sure about that

[Anonymous]

I found a more effective way to debug this by accident; if you instead use the drop down to change the debug type of run a Java Debug under the Debug Run section you get java code in a tab.
From here you can use the line number from the description of the error text (on the "Problems" tab) to find out what line of code is buggy. Based on the great naming convention of the automatically generated code, when you see the line that has an error, it should match the token of the offending field(s) in your tMap.
I hope this helps others.

[Anonymous]

for those who want use java debug for the first time :
http://www.vogella.com/articles/EclipseDebugging/article.html
http://eclipsetutorial.sourceforge.net/debugger.html
have fun !