The problem about JScrollPane,该怎么处理

The problem about JScrollPane
想在JScrollPane中实现滚动条的效果，其中添加了3个label,滚动条没反应，还需要添加什么代码不？

Java code

import java.awt.*;import javax.swing.*;public class TestFrame extends JFrame{        public TestFrame() {        Container mainc = this.getContentPane();        JPanel    p_rslt_future = new JPanel();        p_rslt_future.setLayout(null);        JPanel pscr = new JPanel();        pscr.setLayout(null);        JLabel    day1 = new JLabel("DAY1"),                day2 = new JLabel("DAY2"),                day3 = new JLabel("DAY3");        day1.setBounds(10, 10, 50, 20);        day2.setBounds(10, 100, 50, 20);        day3.setBounds(50, 230, 50, 20);        pscr.add(day1);pscr.add(day2);pscr.add(day3);        JScrollPane sp = new JScrollPane(pscr);                sp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);        sp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);        sp.setBounds(3, 3, 438, 200);        p_rslt_future.add(sp);        mainc.add(p_rslt_future);    }        public static void main(String args[]) {        TestFrame myframe = new TestFrame();        myframe.setSize(450, 235);        myframe.setTitle("TestFrame");        myframe.setVisible(true);        myframe.setResizable(false);        myframe.setLocationRelativeTo(null);        myframe.setDefaultCloseOperation(EXIT_ON_CLOSE);    }}

Java code

JEditorPane jep = new JEditorPane();JScrollPane jsp = new JScrollPane(jep);
[解决办法]
Java code
import java.awt.*;import javax.swing.*;public class TestFrame extends JFrame{        public TestFrame() {        Container mainc = this.getContentPane();        JPanel    p_rslt_future = new JPanel();//        p_rslt_future.setLayout(null);        JPanel pscr = new JPanel();//        pscr.setLayout(null);        JLabel    day1 = new JLabel("DAY1"),                day2 = new JLabel("DAY2"),                day3 = new JLabel("DAY3");        day1.setBounds(10, 10, 50, 20);        day2.setBounds(10, 100, 50, 20);        day3.setBounds(50, 230, 50, 20);        pscr.add(day1);pscr.add(day2);pscr.add(day3);        JScrollPane sp = new JScrollPane(pscr);                sp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);        sp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);        sp.setBounds(3, 3, 438, 200);        p_rslt_future.add(sp);        mainc.add(sp);    }        public static void main(String args[]) {        TestFrame myframe = new TestFrame();        myframe.setSize(50, 60);        myframe.setTitle("TestFrame");        myframe.setVisible(true);        myframe.setLocationRelativeTo(null);        myframe.setDefaultCloseOperation(EXIT_ON_CLOSE);    }}
[解决办法]
Java code
import java.awt.BorderLayout;import java.awt.Component;import java.awt.Container;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.awt.event.WindowListener;import javax.swing.ImageIcon;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.border.TitledBorder;public class RulsFrame extends BaseFrame {    public RulsFrame() {        init();    }    private void init() {        setTitle("Online Exam Ruls");        setSize(321, 450);        setContentPane(createContentPanel());        setDefaultCloseOperation(2);    }    private JPanel createContentPanel() {        JPanel p = new JPanel(new BorderLayout());        ImageIcon img = new ImageIcon(getClass().getResource("dsgsdg.png"));        JLabel label = new JLabel(img);        p.add(BorderLayout.NORTH, label);        p.add(BorderLayout.CENTER, createCenterPanel());        return p;    }    private JScrollPane createCenterPanel() {        JScrollPane p = new JScrollPane();        p.setBorder(new TitledBorder("Ruls"));        JTextArea rules = new JTextArea();        rules.setText("请同学严格遵守考试以下规则，否则视为主动放弃考试:\n1.不准带任何和考试有关的物品\n2.不准在考试期间交头接耳\n3.不准在考试期间泡妹子\n4.不准在考试期间看A片\n5.不准在考试期间吟诗\n\n\nPeople laugh and People cry\nSome give up Some always try\nSome say hi while some say bye\nWe all are walking dead!\n");        rules.setLineWrap(true);        rules.setEditable(false);        p.getViewport().add(rules);        return p;    }} 
 
[解决办法]
探讨


楼上的方法不行呀，有没有帮忙写一个能够实现的例子？

[解决办法]
Java code
import java.awt.*;import javax.swing.*;public class TestFrame extends JFrame{        public TestFrame() {        Container mainc = this.getContentPane();        JPanel pscr = new JPanel();        pscr.setPreferredSize(new Dimension(480, 300));        //设置panel的首选大小，同时保证宽高大于JScrollPane的宽高，这样下面的JScrollPane才能滚动        pscr.setLayout(null);        JLabel    day1 = new JLabel("DAY1"),                day2 = new JLabel("DAY2"),                day3 = new JLabel("DAY3");        day1.setBounds(10, 10, 50, 20);        day2.setBounds(10, 100, 50, 20);        day3.setBounds(50, 230, 50, 20);        pscr.add(day1);        pscr.add(day2);        pscr.add(day3);        JScrollPane sp = new JScrollPane(pscr);                sp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);        sp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);        sp.setBounds(3, 3, 438, 200);        mainc.add(sp);    }        public static void main(String args[]) {        TestFrame myframe = new TestFrame();        myframe.setSize(450, 235);        myframe.setTitle("TestFrame");        myframe.setVisible(true);        myframe.setResizable(false);        myframe.setLocationRelativeTo(null);        myframe.setDefaultCloseOperation(EXIT_ON_CLOSE);    }}
[解决办法]
再看個小例子吧：

Java code
import java.awt.BorderLayout;import java.awt.GridLayout;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;public class JScrollPaneRowHeaderView extends JFrame {  public JScrollPaneRowHeaderView() {    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    JPanel panel = new JPanel(new GridLayout(5, 10));    for (int i = 0; i < 50; i++) {      panel.add(new JLabel("  Label " + i));    }    JScrollPane scrolled = new JScrollPane(panel);    scrolled.setRowHeaderView(new JLabel("Labels: "));    getContentPane().add(scrolled, BorderLayout.CENTER);    pack();    setSize(300, 100);    setVisible(true);  }  public static void main(String[] args) {    new JScrollPaneRowHeaderView();  }}