这段代码有有关问题，哪位高手能帮小弟我看看？左边拉不过去

这段代码有问题，谁能帮我看看？左边拉不过去！
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.List;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.SwingConstants;
import javax.swing.border.EmptyBorder;


public class PanelTest extends JFrame {
private JPanel listPanel;
private JScrollPane leftJScrollPanel;
private JScrollPane playJScrollPanel;
private List playList;
private List leftList;
private JSplitPane split;
private Container cp;

public PanelTest(){
init();
}


public void init(){
this.setSize(new Dimension(300, 379));
this.setTitle("PLAYER");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setResizable(false);
this.setLocation(200, 100);
this.setVisible(true);
}

public void lunchFrame(){
cp = getContentPane();
listPanel = new JPanel();
listPanel.setLayout(new BorderLayout());
//listPanel.setLayout(null);
//listPanel.setBounds(new Rectangle(4,150,289,148));
listPanel.setLocation(4, 150);
listPanel.setSize(new Dimension(289,148));
listPanel.setBorder(BorderFactory.createEtchedBorder());
leftList = new List();
leftJScrollPanel = new JScrollPane(leftList);
//leftJScrollPanel.setBounds(new Rectangle(4,150,100,148));
listPanel.add(leftJScrollPanel,BorderLayout.WEST);
playList = new List();
playJScrollPanel = new JScrollPane(playList);
//playJScrollPanel.setBounds(new Rectangle(100, 150, 189, 148));
listPanel.add(playJScrollPanel,BorderLayout.EAST);
split = new JSplitPane(SwingConstants.VERTICAL,true,leftJScrollPanel,playJScrollPanel );
split.setBorder(new EmptyBorder(0,0,0,0));
listPanel.add(split);
cp.add(listPanel);
}

public static void main(String args[]){
new PanelTest().lunchFrame();
}
}

------解决方案--------------------
List 换成 JList 就行了
AWT的组件是重量级的，Swing的组件是轻量级的，如果把重量级的和轻量级的用在一起，那么重量级的将覆盖掉轻量级的，List是重量级的

你的代码问题多多，帮你改了一下，list内容是空的，所以滚动条没有显示出来，当list有内容了切需要滚动条的时候它自然就出来了

Java code

import java.awt.Dimension;import javax.swing.JFrame;import javax.swing.JList;import javax.swing.JScrollPane;import javax.swing.JSplitPane;import javax.swing.SwingConstants;import javax.swing.border.EmptyBorder;public class PanelTest extends JFrame{    private static final long serialVersionUID = 7699880680422202533L;    private JScrollPane leftJScrollPanel;    private JScrollPane playJScrollPanel;    private JList playList;    private JList leftList;    private JSplitPane split;    public PanelTest()    {        init();    }    public void init()    {        lunchFrame();        this.setSize(new Dimension(300, 379));        this.setTitle("PLAYER");        this.setDefaultCloseOperation(EXIT_ON_CLOSE);        this.setResizable(false);        this.setLocation(200, 100);        this.setVisible(true);    }    public void lunchFrame()    {        leftList = new JList();        leftJScrollPanel = new JScrollPane(leftList);        playList = new JList();        playJScrollPanel = new JScrollPane(playList);        split = new JSplitPane(SwingConstants.VERTICAL, true, leftJScrollPanel, playJScrollPanel);        split.setBorder(new EmptyBorder(0, 0, 0, 0));        //左边的宽度        split.setDividerLocation(120);        getContentPane().add(split);    }    public static void main(String args[])    {        new PanelTest();    }}