java - Convert List<T> to Collection<Object[]> for JUnit Parametrized Test -

i perform junit parametrized test data being external. have list of objects , need know how can convert collection of object arrays. see below stack overflow question, want add data file read method.

parameterized junit tests non-primitive parameters?

working code: this:

@runwith(parameterized.class) public class sampletest {    private branchmailchildsample branch;    public sampletest(branchmailchildsample branch)   {     this.branch = branch;   }    @parameters   public static collection<object[]> data()   {     string excel = "c:\\resources\\testdata\\excelsheets\\branchmail\\branchmail_testdata.xlsx";     excelmarshallertool tool = new excelmarshallertool(excel);     list<branchmailchildsample> items = tool.unmarshallexcel(branchmailchildsample.class);     //right here need help: convert list collection<object[]>      //return items collection of object arrays    }    @test   public void test()   {     system.out.println(branch.tostring());   } } 

you don't have convert list.

@runwith(parameterized.class) public class sampletest {    @parameters(name = "{0}")   public static list<branchmailchildsample> data() {     string excel = "c:\\resources\\testdata\\excelsheets\\branchmail\\branchmail_testdata.xlsx";     excelmarshallertool tool = new excelmarshallertool(excel);     return tool.unmarshallexcel(branchmailchildsample.class);   }    @parameter(0)   public branchmailchildsample branch;    @test   public void test() {     system.out.println(branch.tostring());   } } 

i used field injection, because needs less code constructor injection. setting name object under test prints more helpful output. please have @ documentation of parameterized runner.

you can use constructor injection if don't public field.

@runwith(parameterized.class) public class sampletest {    @parameters(name = "{0}")   public static list<branchmailchildsample> data() {     string excel = "c:\\resources\\testdata\\excelsheets\\branchmail\\branchmail_testdata.xlsx";     excelmarshallertool tool = new excelmarshallertool(excel);     return tool.unmarshallexcel(branchmailchildsample.class);   }    private final branchmailchildsample branch;    public sampletest(branchmailchildsample branch) {     this.branch = branch;   }    @test   public void test() {     system.out.println(branch.tostring());   } }