Java SAX解析器为有效URL抛出403异常

Question

SAX解析器为有效URL抛出403异常，该URL加载时在浏览器中没有任何问题。我们可以使用下面的示例代码来重现该问题。指针表示赞赏。

private DataGridView dgview;
private DataGridViewTextBoxColumn dgviewcol1;
private DataGridViewTextBoxColumn dgviewcol2;
void Search()
{
    dgview = new DataGridView();
    dgviewcol1 = new DataGridViewTextBoxColumn();
    dgviewcol2 = new DataGridViewTextBoxColumn();
    this.dgview.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
    this.dgview.Columns.AddRange(new System.Windows.Forms.DataGridViewTextBoxColumn[] {this.dgviewcol1, this.dgviewcol2}); // "cannot implicitly convert type system.windows.forms.datagridtextboxcolumn to system.windows.forms.datagridviewcolumn"
    dataGridView2.Visible = false;
    this.dgviewcol1.Visible = false; // Visible property doesn't exist in datagridviewtextboxcolumn
    this.dgviewcol2.Visible = false;
    this.Controls.Add(dgview);
    this.dgview.ReadOnly = true;
    dgview.BringToFront();

}

堆栈跟踪如下：

class Parent:
    def __init__(self):
        self.some_field = 'value'    

class Child(Parent):
    def __init__(self):
        self.other_field = 'other_value'
        super().__init__()
child = Child()
child.some_field # 'value'