在JSplitPane里添加JScrollPane,文本区的滚动条不出来，求教

将分割面板上下两部分都加上JScrollPane，再加上JTextArea，文本区不出现滚动条，该怎么办呢？求指教！

[code="java"]
public MainFrame(){
JScrollPane scpane1 =new JScrollPane();
JScrollPane scpane2 =new JScrollPane();
JTextArea ta1 =new JTextArea();
JTextArea ta2 =new JTextArea();
JSplitPane sppane_v = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
sppane_v.setDividerLocation(200);

    this.setBounds(300,200,300,600);
    this.setBackground(java.awt.Color.lightGray);
    this.setDefaultCloseOperation(EXIT_ON_CLOSE);

    Container cont = this.getContentPane();
        cont.add(sppane_v);
    sppane_v.setLeftComponent(scpane1.add(ta1));
    sppane_v.setRightComponent(scpane2.add(ta2));

    this.setVisible(true);
}

[/code]

[code="java"]sppane_v.setLeftComponent(scpane1.add(ta1));

sppane_v.setRightComponent(scpane2.add(ta2));[/code]

改成

[code="java"]sppane_v.setLeftComponent(new JScrollPane(ta1));

sppane_v.setRightComponent(new JScrollPane(ta2)); [/code]

试试看？