Updated @DataProvider on @Factory contained within test class

Just wanted to post an update on using TestNG’s @Factory with @DataProvider.

A few gotcha’s you may encounter:
1) When placing your @DataProvider and @Factory inside the test class you cannot place @Test on the class itself. In the following example doing so will result in: org.testng.TestNGException:
Method createExampleClass requires 3 parameters but 0 were supplied in the @Test annotation. 

2) Make sure to create your @Factory and @DataProvider methods as static

ExampleClass:

public class ExampleClass {
    @DataProvider(name = "data")
    public static Iterator<Object[]> getData() {
        List<Object[]> data = new ArrayList<Object[]>();

        //Our array types must match the @Factory input (String, Integer, Boolean)
        data.add(new Object[]{"Object 1", 1, true});
        data.add(new Object[]{"Object 2", 2, false});

        return data.iterator();
    }

    @Factory(dataProvider = "data")
    public static Object[] createExampleClass(String s, Integer i, Boolean b) {
        //Instantiate the @Test class supplying the constructor our values
        return new Object[]{new ExampleClass(s, i, b)};
    }

    private String s;
    private Integer i;
    private Boolean b;

    //Created with values from @DataProvider in @Factory
    public ExampleClass(String s, Integer i, Boolean b) {
        this.s = s;
        this.i = i;
        this.b = b;
    }

    @Test
    public void unitTest() {
        System.out.println(s + ", " + i + ", " + b);
    }
}

Another “preferred” way to use the constructor as the factory:

public class ExampleClass {
    @DataProvider(name = "data")
    public static Iterator<Object[]> getData() {
        List<Object[]> data = new ArrayList<Object[]>();

        //Our array types must match the @Factory input (String, Integer, Boolean)
        data.add(new Object[]{"Object 1", 1, true});
        data.add(new Object[]{"Object 2", 2, false});

        return data.iterator();
    }

    private String s;
    private Integer i;
    private Boolean b;

    //Created with values from @DataProvider
    @Factory(dataProvider = "data")
    public ExampleClass(String s, Integer i, Boolean b) {
        this.s = s;
        this.i = i;
        this.b = b;
    }

    @Test
    public void unitTest() {
        System.out.println(s + ", " + i + ", " + b);
    }
}