-----------------------------主函数调用-------------------------------
package testGUI;

import javax.swing.JFrame;
import javax.swing.JTabbedPane;

public class TestUI {
	public static void main(String[] args) {
		JFrame f = new JFrame("Hello World");
		f.setSize(800,500);
		f.setLocation(200,100);
		f.setLayout(null);
		
		JTabbedPane panel = new JTabbedPane();
		//panel.setLayout(new BorderLayout());
		String path = "E:/wgxFolder/copysrc/src/j2se";
		SetPageThread tSet = new SetPageThread(panel);
		ReadFileThread tRead = new ReadFileThread(path, tSet);
		tSet.start();
		tRead.start();
		f.setContentPane(panel);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setVisible(true);
	}
}

-----------------------------设置页面线程类-------------------------------

package testGUI;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;

public class SetPageThread extends Thread {
	final public JTabbedPane panel;
	final public List<JavaContents> jcs;

	public SetPageThread(JTabbedPane panel) {
		jcs = new ArrayList<JavaContents>();
		this.panel = panel;
	}
	@Override
	public void run()
	{
		while (true) {
			outAndSetPage();
		}
	}
	public synchronized void in(File f) {
		JavaContents jc = new JavaContents(f.getName());
		try (InputStreamReader isr = new InputStreamReader(new FileInputStream(f));
				BufferedReader reader = new BufferedReader(isr);) {
			String line = "";
			while ((line = reader.readLine()) != null) {
				jc.appen(line);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		jcs.add(jc);
		this.notifyAll();
	}
	public synchronized void outAndSetPage() {
		while(jcs.isEmpty())
		{
			try {
				this.wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		JavaContents temp =  jcs.remove(0); 
		JTextArea txt = new JTextArea();
		txt.setText(temp.sb.toString());
		JScrollPane sp = new JScrollPane(txt);
		panel.addTab(temp.name, sp);
	}
}

class JavaContents {
	public String name;
	public StringBuffer sb;

	public JavaContents(String name) {
		this.name = name;
		sb = new StringBuffer();
	}

	public void appen(String line) {
		sb.append(line);
		sb.append("\r\n");
	}
}

--------------------文件读取类-----------------------

package testGUI;

import java.io.File;

public class ReadFileThread extends Thread {
	private final String path;
	private final SetPageThread t;
	public ReadFileThread(String path,SetPageThread t) {
		this.path = path;
		this.t = t;
	}
	@Override
	public void run()
	{
		read(new File(path));


	}
	private void read(File baseFile)
	{
		try {
			if(baseFile == null||!baseFile.exists())
				return;
			File[]fs = baseFile.listFiles();
			if(fs==null||fs.length<1)return;
			for (File f : fs) {
				String name = f.getName();
				if(name.endsWith(".java"))
				{
					t.in(f);
				}
				if(f.isDirectory())
				{
					read(f);
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.util.Objects;

public class TestGUI {
    public static void main(String[] args) throws IOException {
        // 窗体
        JFrame frame = new JFrame("Eclipse");
        frame.setLocation(1000, 500);
        frame.setSize(800, 600);

        // 主面板
        JTabbedPane tabbedPane = new JTabbedPane();
        frame.setContentPane(tabbedPane);

        // 获取 jdbc 包下的 java 文件
        File[] fileArr = new File("src/jdbc").listFiles(f -> f.getName().endsWith(".java"));
        for (int i = 0; i < Objects.requireNonNull(fileArr).length; i++) {
            File file = fileArr[i];

            // 每个 java 文件，创建一个面板
            JScrollPane scrollPane = new JScrollPane();
            tabbedPane.add(scrollPane);

            // 面板对应的 tab
            tabbedPane.setTitleAt(i, file.getName());
            tabbedPane.setIconAt(i, new ImageIcon("assets/img/j.png"));


            // 面板，添加文本域
            JTextArea textArea = new JTextArea();
            textArea.setLineWrap(true);
            scrollPane.setViewportView(textArea);

            // 文本域，填充文本
            BufferedReader reader = new BufferedReader(new FileReader(file));
            String line;
            while (null != (line = reader.readLine())) {
                textArea.append(line);
                textArea.append("\r\n");
            }
            reader.close();
        }

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

    }
}

import javax.swing.*;
import java.util.HashMap;
import java.util.Map;

public class TestGUI {
    public static void main(String[] args) {
        // 窗体
        JFrame frame = new JFrame("LOL");
        frame.setLocation(1000, 500);
        frame.setSize(500, 400);

        // 主面板
        JPanel leftPanel = new JPanel();
        JPanel rightPanel = new JPanel();
        JSplitPane splitPanel = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftPanel, rightPanel);
        splitPanel.setDividerLocation(80);
        frame.setContentPane(splitPanel);

        // 业务配置
        Map<String, String> config = new HashMap<>();
        config.put("盖伦", "assets/img/gareen.jpg");
        config.put("提莫", "assets/img/teemo.jpg");
        config.put("安妮", "assets/img/annie.jpg");

        // 右边面板
        JLabel label = new JLabel();
        rightPanel.add(label);

        // 左边面板
        config.forEach((k, v) -> {
            JButton button = new JButton(k);
            leftPanel.add(button);

            // 按钮事件
            button.addActionListener(e -> {
                ImageIcon icon = new ImageIcon(v);
                label.setIcon(icon);
            });
        });
        // 默认点击第一个按钮
        JButton firstBtn = (JButton) leftPanel.getComponent(0);
        firstBtn.doClick();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

    }
}

JFrame f = new JFrame("CardJava");
		f.setSize...;
		f.setLocation...;
		f.setLayout(null);
		

		JTabbedPane tp...;

		File fl = new File(...);
		File[] fs = fl.listFiles();
		JTextArea[] ta = new JTextArea[fs.length];
		JScrollPane[] sp = new JScrollPane[fs.length];
		ImageIcon ii = new ImageIcon(...);
		for (int i = 0; i < fs.length; i++) {
			ta[i] = new JTextArea();
			try (
					FileReader fr = new FileReader(fs[i]);
					BufferedReader br = new BufferedReader(fr);
			) {
				while (true) {
					String line = br.readLine();
					if (null == line)
	                    break;
					ta[i].append(line + "\n");
				}
				ta[i].setLineWrap(true);
				sp[i] = new JScrollPane(ta[i]);
				tp.add(sp[i]);
				tp.setTitleAt(i,fs[i].getName());
				tp.setIconAt(i, ii);
				br.close();
				fr.close();
			} catch (IOException e) {
				// TODO 自动生成的 catch 块
				e.printStackTrace();
			}
		}
		
		f.setContentPane(tp);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setVisible(true);

JFrame f = new JFrame(...);
		f.setSize...;
		f.setLocation...;
		f.setLayout(null);
		
		// 分页
		JPanel pLeft...;
		pLeft.setBackground...;
		pLeft.setLayout(new FlowLayout());
		
		JButton b1...;
		JButton b2...;
	    JButton b3...;
		
	    pLeft.add(...);
	    
		JPanel pRight...;
		pRight.setBackground...;
		
		JLabel l...;
		
		ImageIcon ... = new ImageIcon(...);
				
		// 默认设置ImageIcon
		l.setIcon...;
		
		// label的大小设置为ImageIcon，否则显示不完整  setBounds在分隔面板中设置的位置不起作用
		l.setBounds(...);

		
		pRight.add(l);
		
		JSplitPane sp...;
		sp.setDividerLocation(...);
		f.setContentPane(sp);
		
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setVisible(true);
		
		b1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (b1.getText() == ...) {
					// 设置ImageIcon
					l.setIcon(...);
				}
			}
		});
		...