Java Annotations -- What is Happening In This Code?-CodePudding

I'm a moderately-experienced Java coder who never quite wrapped my head around Java Annotations. I've read through the documentation a few times and stepped through online examples, and I understand the basic concept: Annotations are essentially metadata for your code.

Now my boss has asked me to look at Java code written by another employee who has since left our company. Here's the most important method:

public XSSFWorkbook  myExcelWorkbook;
public XSSFSheet     myExcelSheet;
public Object        data = null;

@DataProvider(name = "GetConfigData")
public Object GetExcelData() throws IOException {
    try {
        ExcelUtility utility = new ExcelUtility();
        myExcelSheet = utility.getSheet(myExcelWorkBook, "CONFIG_DETAILS");
        data = utility.readDataToList(myExcelSheet);
    } catch (Exception e) {
        log.error("ERROR DETAILS: "   e.getMessage());
    }
    return data;
}

So this method opens an Excel spreadsheet, reads it, and analyzes the data for later in the program. I understand everything here...

...except that @DataProvider(name = "GetConfigData") part. I don't think its just helpful information for a human reader like me. I suspect it is manipulating the code somehow, but I'm not sure how.

More mystery: When I do a text search for "DataProvider" or "GetConfigData", I find nothing.

Also, when I do a "Open Call Hierarchy" on GetExcelData() (I'm working in Eclipse), I can't find another method who is calling GetExcelData(). But GetExcelData() is clearly being invoked when the code runs. Would the Annotations possibly explain how?

I realize this is just a code snippet and prob not enough information to completely answer my questions. But I'm hoping someone might explain what specific role that Annotation line is playing here. Thank you in advance, -RAO

CodePudding user response：

But GetExcelData() is clearly being invoked when the code runs. Would the Annotations possibly explain how?

Yes.

The annotation is causing the framework to recognize that method as a data provider.

CodePudding user response：

For anyone who may be looking at this post:

So I just learned that the code uses TestNG, which uses the @DataProvider annotation to implement. Rookie mistake...