Beanshell assertion throwing exception when comparing null values - jmeter

Question

I have below beanshell asserstion code; this code seems to give an exception when value3 has null value. It works fine otherwise.
I think it has to do something with BigDecimal, but I am not sure how to handle null values. Can some one please help me with it ?
import java.math.BigDecimal;
import java.math.RoundingMode;
String value3 = vars.get("budget_api");
String value4 = vars.get("c_budget_1");
if(value3 != null) {
BigDecimal value10 = new BigDecimal(value3);
String value11 = value10.setScale(8, RoundingMode.HALF_UP).stripTrailingZeros().toPlainString();
if(!value11.equals(value4)) {
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value11 + " db: "+ value4;
print(FailureMessage);
}
}
else {
if(value4 != null) {
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value3 + " db: "+ value4;
print(FailureMessage);
}
}

Answer 1

Your "throwing exception" stanza is very informative and the only advice I can give you right away is "fix your code".
You can get a way more comprehensive error message if you surround your code in try block like:
try {
//your code here
}
catch (Throwable ex) {
log.error("Beanshell failure", ex);
throw ex;
}
Once done you will be able to see "normal" stacktrace in jmeter.log file, you should be able to figure out the root cause of the problem from it. If not - at least you will be able to add it to your question so the community could come up with suggestions.
My expectation is that your budget_api variable value is not null, but something which cannot be cast to BigDecimal.
Also consider moving to JSR223 Assertion and Groovy language as Beanshell performance can be a big question mark when it comes to high loads, check out Scripting JMeter Assertions in Groovy - A Tutorial article to get started.

Answer 2

I see a few possible failures here:
When value3 is not null, but is not a valid BigDecimal (for example an empty string)
When new BigDecimal throws an exception
When value10 is null
When setScale throws an exception
When value11 is null
So I would change your code like this:
import java.math.BigDecimal;
import java.math.RoundingMode;
String value3 = vars.get("budget_api");
String value4 = vars.get("c_budget_1");
BigDecimal value10 = null;
String value11 = null;
if(value3 != null) {
try {
value10 = new BigDecimal(value3); // addresses issues 1 and 2
} catch(NumberFormatException e) {
// whatever you want to do if conversion failed;
// value 10 will remain null in this case
}
}
if(value10 != null) { // addresses issue 3
try { // addresses issue 4
value11 = value10.setScale(8, RoundingMode.HALF_UP).stripTrailingZeros().toPlainString();
} catch(ArithmeticException e) {
// value 11 will remain null
}
}
if(value11 != null) { // addresses issue 5
if(!value11.equals(value4)) {
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value11 + " db: "+ value4;
print(FailureMessage);
}
}
else {
if(value4 != null) {
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value3 + " db: "+ value4;
print(FailureMessage);
}
}
Now if you look at this code, you may notice a few optimizations, that could make it faster and more readable. It doesn't lead to shorter code, but it makes script exit as soon as it discovered that comparison will fail.
If both value4 and value3 are null, there's no point to do the rest of the juggling.
If either value3 is null, or value4, but not both (which is covered by case 1), no point to calculate, we already know they are different.
If value3 cannot be converted to BigDecimal, while we know that value4 is not null, script can exit with failure as well
If value11 was not obtained, it's the same thing as comparison failure
So here's an optimized version:
import java.math.BigDecimal;
import java.math.RoundingMode;
String value3 = vars.get("budget_api");
String value4 = vars.get("c_budget_1");
BigDecimal value10 = null;
String value11 = null;
if(value3 == null && value4 == null) { // optimization 1
return;
}
if(value3 == null || value4 == null) { // optimization 2
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value3 + " db: "+ value4;
print(FailureMessage);
return;
}
// no longer need to check if value3 is null, since previous checks would make sure script exits if it is
try {
value10 = new BigDecimal(value3);
} catch(NumberFormatException e) {
// value10 remains null
}
if(value10 == null) { // optimization 3
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value3 + " db: "+ value4;
print(FailureMessage);
return;
}
// no longer need to check if value10 is null, since previous checks would make sure script exits if it is
try {
value11 = value10.setScale(8, RoundingMode.HALF_UP).stripTrailingZeros().toPlainString();
} catch(ArithmeticException e) {
// value11 will remain null
}
if(value11 == null || !value11.equals(value4)) { // optimization 4
Failure = true;
FailureMessage = ": budget doesnt match, api: "+ value3 + " db: "+ value4;
print(FailureMessage);
return;
}