CODEWITHSUNDEEP
java
zkokaja
zkokaja

Reputation: 93

How do I use the JavaCompiler in javax.tools to produce more detailed diagnostics or give me an exception stack trace?

I want to be able to dynamically compile a Java file and handle any compile errors and exceptions one by one. So I looked at JavaCompiler, and there's an example used to collect diagnostics:

Iterable<? extends JavaFileObject> compilationUnits = ...;
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();
StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null);
compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnits).call();

for (Diagnostic diagnostic : diagnostics.getDiagnostics())
    System.out.format("Error on line %d in %d%n",
                      diagnostic.getLineNumber()
                      diagnostic.getSource().toUri());

fileManager.close();

This is all fine and dandy, except that the Diagnostic objects I get back are not very helpful in determining exactly what compile error occurred during compilation. There is a getMessage() and getCode() method that helps determine more specifics, but the API says:

The actual message is implementation-dependent.

Which seems not very useful for portability, and if I was to parse it, I'd be doing it in a round-about way. So I'm wondering if I'm missing something when reading the API, or is there a better alternative to the javax.tools package.

Upvotes: 1

Views: 239

Answers (1)

user207421
user207421

Reputation: 310936

You don't get exception stack traces from a compiler. If you did it would be a sign of an internal compiler failure, not a fault in your code. I don't know what you're expecting exactly but the diagnostic messages are about all there is.

Upvotes: 1

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