Your Guide to Debugging With VSCode

Debugging Java applications can present a variety of challenges, including concurrency issues, memory management, complex stack traces and more. In more detail, these include: 

• Concurrency issues related to multithreaded applications such as race conditions and deadlocks. 

• Memory management including memory leaks where the garbage collector is unable to release objects no longer needed and can lead to out of memory errors. 

• Performance issues, identifying bottlenecks, and the effect of the JIT compiler.  

• Complex stack traces caused by Java’s extensive use of exceptions can make tracking down issues challenging. 

• Environment and configuration issues, such as classpath problems and environment differences. 

• Third party libraries, which may contain software bugs, and can have versioning issues. 

• Security restrictions, particularly in web applications, can restrict certain operations.  

• Distributed systems, which have their own challenges requiring remote debugging and may make use of microservices. 

• Dynamic behavior, reflection and proxies can obscure the flow of the program and make static analysis tools less effective. 

• CI/CD pipelines, managing pipelines from build tools such as Maven and Gradle can introduce their own complexities.  

Looking to get started using the VSCode debugger for your Java application? Follow these simple steps: 

• Start debugging the current file by pressing F5 or selecting Run and Debug on the Debug start view. 

• For most scenarios create a launch configuration file, which allows for editing and updating and is saved as a launch.json file in a .vscode folder. 

• Set breakpoints by clicking in the editor margin or selecting F9 on the line number 

• Conditional breakpoints can be set based on expressions, hit counts, or a combination of both. 

• Logpoints can be used to log a message to the debug console without stopping the application. Logpoints are created by using the Add Logpoint command in the left editor gutter or by using the Debug: Add Logpoint command. 

• Inspect variables in the variables section of the Run and Debug view or by hovering a mouse over the variable to see the value. 

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Debugging in high level languages such as Java is comparatively easier than debugging in low level languages like C or C++. That’s because Java has features built into the language such as exception handling, memory management and type checking. In programming languages such as C and C++, memory is not explicitly managed and ensuring proper memory management is the responsibility of the programmer. Memory debugging tools may be required to debug lower level languages.  

Debugging in Java is similar to other languages in that you would typically use an IDE such as IntelliJ, VSCode or Eclipse to set breakpoints in the code, step through the code, and inspect the value of variables, arrays and data structures. 

📚 Want to learn more about the array of Java IDEs?  Check out this 101 Guide.  

Final Thoughts on Debugging in VSCode