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Error messages while throwing exceptions

I was very concerned about exceptions, how they are thrown and handled. I define a proper error code before throwing some error. I never been to a production site, but this time I got a chance to be a implementation team. The way I handled my exceptions seems to be incomplete. Though, my error messages in exception was good, but it still missing a feature, which could help production people. Many of you might not aware of the very fact that, the logging level is severe in production. Then way you log the data in the codes is always helpful, but try to handle your error message for exceptions efficiently that you need not to enable logging to finer levels to analyze the issue. The errors must be self explanatory.

Analyze the code snippet mentioned below:

public void fetchCurrencyOffset(String bankCode, String branchCode, String currencyCode1, String currencyCode2) {
            try {
                  Map<String, Object> objectMap = new HashMap<String, Object>();
                  objectMap.put(CommonServicesConstants.CURRENCY_CODE_ONE, currencyCode1);
                  objectMap.put(CommonServicesConstants.CURRENCY_CODE_TWO, currencyCode2);
                  objectMap.put(CommonServicesConstants.BRANCH_CODE, branchCode);
                  objectMap.put(CommonServicesConstants.BANK_CODE, bankCode);
                  executeNamedQuery(CommonServicesQueryConstants.QUERY_TOGET_CCY_OFFSETFLAG, objectMap);
            } catch (BusinessException e) {
                  throw new BusinessException(CommonServicesErrorConstants.FAILED_LOAD_CURRENCY_PAIR);
            }
      }
      private void executeNamedQuery(String queryName, Map<String, Object> objectMap) {
            // Fire DataBase query.
      }  

It seems perfectly right, I don’t see any error in the above code snippet. Whenever, something breaks here in the above code snippet, it will surely, throw a relevant Business Exception. So, check the exception stack trace, how it looks like.

[2011-07-11T19:43:00.097+10:00] [host_server1] [ERROR] [] [com.test.practice.CurrencyService] [tid: [ACTIVE].ExecuteThread: '14' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: xxxxxx] [ecid: e9e4f880efb8a51d:-28bac7cc:1310f48109c:-8000-00000000000090af,0] [APP: xxxxxxx-middleware] XX_CS_CY_1015[[
com.test.practice.framework.exception.BusinessException: Failed to load Currency Pair
at com.test.practice.commonservice.currency.CurrencyService.fetchCurrencyOffset(CurrencyService.java:3891)
at com.test.practice.commonservice.currency.CurrencyService.fetchSpotRate(CurrencyService.java:1481)

Looking at the above stack trace, one can easily identify the error. So, I was in the dilemma that this is a good error message for exceptional handling practice. But I encountered this error in the production site also. When I was asked to look into the issue, I analyzed this issue and reported that Currency pair was missing from the database. When my supervisor asked me that which currency pair was missing?..I was like, I don’t have any answer, I asked him to enable the log level to fine level to check that. So, the problem was solved at that time. This is the point when I realized the importance of error messages of exception handling. Thus. I started looking for some alternative ways for the same. And, finally I discovered this, analyze the same code snippet now :

public void fetchCurrencyOffset(String bankCode, String branchCode, String currencyCode1, String currencyCode2) {
            try {
                  Map<String, Object> objectMap = new HashMap<String, Object>();
                  objectMap.put(CommonServicesConstants.CURRENCY_CODE_ONE, currencyCode1);
                  objectMap.put(CommonServicesConstants.CURRENCY_CODE_TWO, currencyCode2);
                  objectMap.put(CommonServicesConstants.BRANCH_CODE, branchCode);
                  objectMap.put(CommonServicesConstants.BANK_CODE, bankCode);
                  executeNamedQuery(CommonServicesQueryConstants.QUERY_TOGET_CCY_OFFSETFLAG, objectMap);
            } catch (BusinessException e) {
                  throw new BusinessException(CommonServicesErrorConstants.FAILED_LOAD_CURRENCY_PAIR, currencyCode1, currencyCode2);
            }
      }
      private void executeNamedQuery(String queryName, Map<String, Object> objectMap) {
            // Fire DataBase query.
      }


The above snippet also looks the same except the line where business exception is thrown.
Now, when the same error comes again, the stack trace looks a bit different.

[2011-07-11T19:43:00.097+10:00] [host_server1] [ERROR] [] [com.test.practice.CurrencyService] [tid: [ACTIVE].ExecuteThread: '14' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: xxxxxx] [ecid: e9e4f880efb8a51d:-28bac7cc:1310f48109c:-8000-00000000000090af,0] [APP: xxxxxxx-middleware] XX_CS_CY_1015[[
com.test.practice.framework.exception.BusinessException: Failed to load Currency Pair with ccy1 : INR and ccy2 : AUD
at com.test.practice.commonservice.currency.CurrencyService.fetchCurrencyOffset(CurrencyService.java:3891)
at com.test.practice.commonservice.currency.CurrencyService.fetchSpotRate(CurrencyService.java:1481)

Just a small change is required in the error message resource bundle and I was done.

So, after looking this stack trace, I can easily figure out the missing pair of currencies. Thus, for any error message, we always pass some piece of information in the error messages so, we need not to enable the fine level of the logging every time.
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