OK, so you have a list of points which you need to iterate and draw lines between, something like:
Gl.glBegin(Gl.GL_LINES);
for (int i = 0; i < coordinate.size; i +=2)
{
Gl.glVertex3f(coordinate[i][0], coordinate[i][1], coordinate[i][2]);
Gl.glVertex3f(coordinate[i+1][0], coordinate[i+1][1], coordinate[i+1][2]);
}
Gl.glEnd();
Which basically draws a line between each pair of vertices. If the ending point of one vertex is the same as the beginning of the next, then change the increment value of the loop to 1 rather than 2.