Spring Exception Logging: Find Errors Fast

The Problem: Logs Exist, But Root Cause Is Missing

You have error logs in production, but still can’t answer:

“Where did this error actually happen?”

Typical logs look like this:

log.error("Error occurred");

or:

log.error(e.getMessage());

These logs are almost useless for debugging.

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Why This Happens

In Spring, global exception handling is usually implemented with:

• @RestControllerAdvice

However, this layer is not where the error originates.

The real issue is:

You're not using the Exception object correctly.

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Key Insight: Exception Already Contains Everything

An Exception in Java is not just a message.

It contains:

• Full call stack
• Exact class and method
• Line number of failure

This is captured at the moment the error occurs.

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Solution: Proper Exception Logging

1. Always log with the Exception object

log.error("stacktrace ↓↓↓", e);

This prints:

• Full stack trace
• Root cause
• Execution flow

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2. Extract the exact failure point

private String getRootStack(Exception e) {  
    StackTraceElement ste = e.getStackTrace()[0];  
    return ste.getClassName() + "." +  
           ste.getMethodName() +  
           "(" + ste.getFileName() + ":" + ste.getLineNumber() + ")";  
}

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3. Production-ready log format

log.error("""  
[GLOBAL_EXCEPTION]  
traceId   = {}  
uri       = {}  
method    = {}  
errorType = {}  
errorAt   = {}  
message   = {}  
""",  
traceId,  
request.getRequestURI(),  
request.getMethod(),  
e.getClass().getSimpleName(),  
getRootStack(e),  
e.getMessage(),  
e  
);

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4. Add traceId for request tracking

MDC.put("traceId", UUID.randomUUID().toString());

This allows you to:

Track all logs within a single request

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Real Impact

Instead of vague logs:

Error occurred

You get:

traceId=ab12cd34
errorAt=OrderService.createOrder(OrderService.java:42)

→ Jump directly to the failing line
→ Debug in minutes instead of hours

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Takeaway

Good logging is not about logging more.

It’s about logging in a way that makes root cause immediately visible.