help review array of object code [closed]

public class DoubleMatrix
{
private double[][] doubMatrix;  

public DoubleMatrix(int row, int col)
{       
    if(row > 0 && col > 0)
    {
        makeDoubMatrix(row,col);
    }
    else
    {
        row = 1;
        col = 1;
    }
}

public DoubleMatrix(double[][] tempArray) 
{
    if(tempArray != null)
    {
        for(int i = 0; i < tempArray.length-1;i++)
        {
            if(tempArray[i].length == tempArray[i+1].length)
            {
                tempArray = doubMatrix;

            }
        }
    }
    else
    {
        makeDoubMatrix(1,1);
    }
}

public int getDim1()
{
    return doubMatrix.length;
}

public int getDim2()
{
    return doubMatrix[0].length;
}

private void makeDoubMatrix(int row, int col)
{
    double[][] tempArray  = new double[row][col];
    for(int i = 0;i < tempArray.length;i++)
        for(int j = 0;j < tempArray[i].length;j++)
        {
            tempArray[i][j] = Math.random() * (100);            
        } //end for   
    doubMatrix = new double[row][col];
    doubMatrix = tempArray;
}

public DoubleMatrix addMatrix(DoubleMatrix secondMatrix)
{   
    //this. doubMatrix = doubMatrix;
    double[][] tempArray;
    if(secondMatrix.doubMatrix.length == doubMatrix.length)
        if(secondMatrix.doubMatrix[0].length == doubMatrix[0].length)
        {
            tempArray = new double[doubMatrix.length][doubMatrix[0].length]; 
            for(int i = 0; i< secondMatrix.doubMatrix.length;i++)
                  for(int j = 0; j< secondMatrix.doubMatrix[i].length;j++ )
                  {
                      tempArray[i][j] = secondMatrix.doubMatrix[i][j] + doubMatrix[i][j];// add two matrices 
                  }//end for    
            return new DoubleMatrix (tempArray);
        }


            return  new DoubleMatrix(1,1);                                  
}


public DoubleMatrix getTransposedMatrix()
{
    double[][] tempArray = new double[doubMatrix.length][doubMatrix[0].length];
    for(int i = 0;i < doubMatrix.length;i++)
        for(int j = 0;j < doubMatrix[i].length;j++)
        {
            tempArray[j][i] = doubMatrix[i][j];// transposed    matrix2           
        }//end for          
    return new DoubleMatrix(tempArray);
}

public DoubleMatrix multiplyingMatrix(DoubleMatrix secondMatrix)
{   
    double[][] tempArray = new double[secondMatrix.doubMatrix.length][doubMatrix[0].length];
    //check if dimension of matrix1 equal to dimension of matrix2  
    if(secondMatrix.doubMatrix[0].length == doubMatrix.length)
        if(doubMatrix.length == secondMatrix.doubMatrix[0].length)
    {

             for (int i = 0; i <secondMatrix.doubMatrix.length; i++)
               {
                   for(int j = 0; j < doubMatrix[0].length; j++)
                    {

                       for (int k = 0; k < doubMatrix.length; k++)
                       {
                           tempArray[i][j] = tempArray[i][j] + secondMatrix.doubMatrix[i][k]*doubMatrix[k][j]; // multiply 2 matrices

                       }
                    }
               }//end for   
    }// end if



            return new DoubleMatrix(1,1);                   
}

public void printMatrix(String text)
{       
    System.out.println(text);// output string
    for(int i = 0; i< doubMatrix.length;i++)
    {
          for(int j = 0; j< doubMatrix[i].length;j++ )
          {                  
              System.out.printf("%9.1f", doubMatrix[i][j]);// out put value for matrices                
          }  
          System.out.println();
    }
}
}

public class Program3 
{
public static void main(String[] args)
{
    int num1 = (int) (Math.random()*(10-3+1)+3);
    int num2 = (int) (Math.random()*(10-3+1)+3);        
    DoubleMatrix doubMatObj1 = new DoubleMatrix(num1,num2);
    DoubleMatrix doubMatObj2 = new DoubleMatrix(doubMatObj1.getDim1(),doubMatObj1.getDim2());
    DoubleMatrix doubMatObj3;

    doubMatObj3 = doubMatObj1.addMatrix(doubMatObj2);
    doubMatObj1.printMatrix("First Matrix Object");
    doubMatObj2.printMatrix("Second Matrix Object");
    doubMatObj3.printMatrix("Result of Adding Matrix Objects");
    doubMatObj2 = doubMatObj2.getTransposedMatrix();
    doubMatObj2.printMatrix("Result of inverting Matrix Object");
    doubMatObj3 = doubMatObj1.multiplyingMatrix(doubMatObj2);
    doubMatObj3.printMatrix("Result of Multiplying Matrix Objects");
}

}

can someone help me to review this code ? There is an error in this code said there is a NullPointerException but the only reason for it o be null is if doubMatrix is null, and I initialize doubMatrix in makedoubMatrix method, also when I use a printf line to find what is the doubMatrix length, it seems to be 1 everywhere in the code.This is my output which is wrong it only read 1 element

First Matrix Object
     69.1
Second Matrix Object
     30.0
Result of Adding Matrix Objects
Exception in thread "main" java.lang.NullPointerException
    at homework3.DoubleMatrix.printMatrix(DoubleMatrix.java:127)
    at homework3.Program3.main(Program3.java:16)