Java-二维数组-仅正确分配了数组最后一行的值，其余部分分配为null

Question

I have an XML as below format;

    <TestCase>
    <Step Sel = "deleteAllVisibleCookies" Obj = "All cookies" Val = ""></Step>
    <Step Sel = "open" Obj = "URL" Val = "UserName:Password"></Step>
    <Step Sel = "waitForElementPresent" Obj = "link=mobile" Val = ""></Step>
    <Step Sel = "clickAndWait" Obj = "Mobile link" Val = ""></Step>
    ...
    </TestCase>
    <TestCase>
    <Step Sel = "deleteAllVisibleCookies" Obj = "All cookies" Val = ""></Step>
    <Step Sel = "open" Obj = "URL" Val = "UserName:Password"></Step>
    <Step Sel = "waitForElementPresent" Obj = "link=mobile" Val = ""></Step>
    <Step Sel = "clickAndWait" Obj = "Mobile link" Val = ""></Step>
    ...
    </TestCase>

based on above XML file, I am creating an object. I am trying to save all steps in to two dimensional array. So one row is one test case.

int i=0;
int j=0;
for (int TC = 0; TC < TCLst.getLength(); TC++)
    int k=0;
Node TCLstNode = TCLst.item(TC);
if (TCLstNode.getNodeType() == Node.ELEMENT_NODE)
{
    NodeList StepLst = TCLstNode.getChildNodes();
    Step = new String [TCCount][StepLst.getLength()];//defining total length
    Sel = new String [TCCount][StepLst.getLength()];
    Obj = new String [TCCount][StepLst.getLength()];
    Val = new String [TCCount][StepLst.getLength()];
    for (int Step = 0; Step < StepLst.getLength(); Step++)
    {
        Node StepLstNode = StepLst.item(Step);
        if (StepLstNode.getNodeType() == Node.ELEMENT_NODE)
        {
            if (StepLstNode.getNodeName() == "Step")
            {
                Sel[i][k] = ObjectType.getAttribute(StepLstNode,"Sel");//returns value of Sel attribute
                Obj[i][k] = ObjectType.getAttribute(StepLstNode,"Obj");
                Val[i][k] = ObjectType.getAttribute(StepLstNode,"Val");
                stepCountInTC++;
                k++;
            }
        }//NodeType
    }//for
    i++;
    stepCountInATCOfModule[j] = stepCountInTC;
    j++;
    stepCountInTC = 1;
}//TC if

Issue which I am facing is after the object is created, on printing anyone of the two dimensional arrays i am getting output as (here i used Sel attribute);

[[null, null, null, null,...][deleteAllVisibleCookies, open, waitForElementPresent, clickAndWait,...]]

Problem here first test case value is saved as null. If i use XML with 3 test cases then first 2 test cases are saving as null and third case is properly saved to array.

Also please suggest any collection to use instead of two dimensional array.

Answer 1

You miss the braces here:

for (int TC = 0; TC < TCLst.getLength(); TC++)
    int k=0;

The code after this 2 rows are independent of this for because java thinks you do this:

for (int TC = 0; TC < TCLst.getLength(); TC++) {
    int k=0;
}

thus k will always be 0 .

There are multiple problems with you code which need fixing. For example:

Step = new String [TCCount][StepLst.getLength()];

and

int Step = 0

Step is eiher an int or something else (which is not visible in the code) mixing them up is not a good thing. You also no use camelCase variable names.

Answer 2

In every outer loop you override the whole array with a new one here:

Step = new String [TCCount][StepLst.getLength()];//defining total length

Means at the end you find only the last result on the Step variable.

You have to do something like this:

int length = 10;
String[][] Step = new String[length][];

for (int i = 0; i < length; i++)
{
  int innerLength = 2;
  Step[i] = new String[innerLength];

  for (int j = 0; j < innerLength; j++)
  {
    Step[i][j] = "Value";
  }
}