swing学习

2022-09-12 08:03:16

1.Swing组件类的层次
　　Swing组件分从显示效果上分为两种类型：JComponent类和Window类；
　　　　JComponent组件主要包括一些不能独立显示的组件（必须依附与其他组件才能显示）。
　　　　　　JPanel
　　　　　　JTable
　　　　　　JTree
　　　　　　JTextArea
　　　　　　JTextField
　　　　　　JButton
　　　　Window组件类主要包括可以独立显示的组件。
　　　　　　JFrame
　　　　　　JDialog

　　Swing组件从功能上分为三种类型：
　　　　*组件（*容器，可以独立显示）
　　　　　　JFrame、JApplet、JDialog、JWindow
　　　　中间组件
　　　　　　中间容器类（可以充当容器，但不能独立显示）
　　　　　　JPanel、JScrollPane、JSplitPane、JToolBar
　　　　　　特殊中间组件类（在GUI上起特殊作用的中间层，属于中间容器类，但是能起到美化和专业化的作用）
　　　　　　JInternalFrame、JLayeredPane、JRootPane等
　　　　基本组件（实现人机交互的组件，只能依附于中间组件才能显示）
　　　　　　JButton、JComboBox、JList、JMenu、JSlider、JTextField等

2.Window类
　　一切图形化的东西必须包括在*容器内。Swing中主要有三种可以使用的*容器：
　　　　JFrame（用于设计类似于Windows系统中的窗口程序）
　　　　　　内容面板（ContentPane）
　　　　　　　　基本组件
　　　　　　菜单条
　　　　JDialog（用于设计对话框）

3.JComponent类（所有轻量级组件的父类）
　　JComponent的九大特性：
　　　　Tooltips工具提示功能（鼠标停在组件上，显示提示），通过setToolTipText实现
　　　　绘画和边框（setBorder，BorderFactory）
　　　　可插入的观感器（定制自己的桌面，更换新的颜色方案，包括默认、Motif和Windows的L&F）
　　　　自定义属性
　　　　layout支持
　　　　无障碍
　　　　拖拽支持
　　　　双缓冲
　　　　键绑定

4.布局管理器　　

　　BorderLayout：东、南、西、北、中；（默认布局，默认被放置到中）

　　FlowLayout：按照加入的先后顺序排列，行满换行；从左到右，居中排列；

　　GridLayout：将空间划分为网状区域；

　　GriBagLayout：网状划分，功能较GridLayout复杂；

　　　　//太复杂了,给你个链接 https://www.cnblogs.com/aipan/p/6831872.html
　　CardLayout：将组件当成卡片，每一只能显示一个。

　　BoxLayout：通过允许在容器中水平或垂直的方式安排多个组件；
　　SpringLayout：通过定义组件边沿的关系来实现布局；
　　GroupLayout：指定一个窗体上组件彼此之间的关系。

　　绝对定位，setLayout(null)把布局管理器设置为空，为每个组件调用setBounds()放啊发传递位置

5.常见组件

　　JPanel 普通面板组件

　　JScrollPane 带滚动的面板组件

　　JSplitPane 带分割的面板组件

　　JTabbedPane 选项卡组件

　　JLabel 标签

　　JTextField 文本框

　　JTextArea 文本区域

　　JPasswordField 密码框

　　JRadioButton ButtonGroup 单选框

　　JCheckBox 复选框

　　JMenuBar

6. Swing与并发

　　　　当你使用swing编程时，就是在使用线程。在本章开头曾说过，所有的事物都应该通过SwingUtilities.invokeLater(）提交swing事件分发线程。但是，不用显示的创建Thread对象这一事实意味着多线程问题可能会让你大吃一惊，你必须牢记存在着一个Swing事件分发线程，他始终在那里，通过从事件队列中拉出每个事件并依次执行它们，来处理所有的swing事件。牢记事件分发线程，将有助于确保你的应用免遭死锁和竞争条件影响。本节将讲述在使用Swing时所产生的多线程问题。

package com.example.demo.swing;

import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.TimeUnit;

import javax.swing.JButton;
import javax.swing.JFrame;

public class LongRunningTask extends JFrame{
    private JButton b1 = new JButton("Start long Running Task");
    private JButton b2 = new JButton("End long Running Task");
    
    public LongRunningTask() {
        b1.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    TimeUnit.SECONDS.sleep(3);
                } catch (InterruptedException e1) {
                    e1.printStackTrace();
                }
                System.out.println("Task completed");
            }
        });
        b2.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                Thread.currentThread().interrupt();
            }
        });
        setLayout(new FlowLayout());
        add(b1);
        add(b2);
        
    }
    
    public static void main(String[] args) {
        SwingConsole.run(new LongRunningTask(), 200, 150);
    }
}

　　存在的问题，点击按钮之后无响应，点击第二个按钮并不会中断等待。

package com.example.demo.swing;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import javax.swing.JButton;
import javax.swing.JFrame;

class Task implements Runnable{
    private static int counter = 0;
    private final int id = counter++;
    
    @Override
    public void run() {
        System.out.println(this + " started");
        try {
            TimeUnit.SECONDS.sleep(3);
        } catch (InterruptedException e) {
            System.out.println(this + " interrupted");
            return;
        }
        System.out.println(this + " comleted");
    }
    
    public String toString() {
        return "Task " + id;
    }
    
    public long id() {
        return id;
    }
    
}

public class InterruptableLongRunningTask extends JFrame{
    private JButton b1 = new JButton("Start long Running Task");
    private JButton b2 = new JButton("End long Running Task");
    
    ExecutorService executorService = Executors.newSingleThreadExecutor();
    
    public InterruptableLongRunningTask() {
        b1.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                Task task = new Task();
                executorService.execute(task);
                System.out.println(task + " added to the queue");
            }
        });
        b2.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                executorService.shutdownNow();
            }
        });
        setLayout(new FlowLayout());
        add(b1);
        add(b2);
    }
    
    public static void main(String[] args) {
        SwingConsole.run(new InterruptableLongRunningTask(), 200, 150);
    }
}

　　仍然存在问题shutdownNow(）之后不能再执行任务了，所以需要Callable/Future.

public class TaskItem<R,C extends Callable<R>> {
    public final Future<R> future;
    public final C task;
    
    public TaskItem(Future<R> future,C task) {
        this.future = future;
        this.task = task;
    }
}

public class TaskManager<R,C extends Callable<R>> extends ArrayList<TaskItem<R,C>>{
    private ExecutorService exec = Executors.newSingleThreadExecutor();
    
    public void add(C task) {
        add(new TaskItem<R, C>(exec.submit(task), task));
    }
    
    public List<R> getResults(){
        List<R> result = new ArrayList<>();
        Iterator<TaskItem<R, C>> items = iterator();
        while(items.hasNext()) {
            TaskItem<R, C> item = items.next();
            if(item.future.isDone()) {
                try {
                    result.add(item.future.get());
                } catch (InterruptedException | ExecutionException e) {
                    e.printStackTrace();
                }
                items.remove();
            }
        }
        return result;
    }
    
    public List<String> purge(){
        Iterator<TaskItem<R, C>> items = iterator();
        List<String> results = new ArrayList<>();
        while(items.hasNext()) {
            TaskItem<R, C> item = items.next();
            if(!item.future.isDone()) {
                results.add("Cancelling "+item.task);
                item.future.cancel(true);
                items.remove();
            }
        }
        return results;
    }
}

============================================================================================================================

class Task implements Runnable{
    private static int counter = 0;
    private final int id = counter++;
    
    @Override
    public void run() {
        System.out.println(this + " started");
        try {
            TimeUnit.SECONDS.sleep(3);
        } catch (InterruptedException e) {
            System.out.println(this + " interrupted");
            return;
        }
        System.out.println(this + " comleted");
    }
    
    public String toString() {
        return "Task " + id;
    }
    
    public long id() {
        return id;
    }
    
}

class CallableTask extends Task implements Callable<String>{

    @Override
    public String call() throws Exception {
        run();
        return "Return value of " + this;
    }
    
}

public class InterruptableLongRunningCallable extends JFrame{
    private JButton b1 = new JButton("Start Long Running Task");
    private JButton b2 = new JButton("End Long Running Task");
    private JButton b3 = new JButton("Get results");
    
    private TaskManager<String, CallableTask> manager = new TaskManager<>();
    
    public InterruptableLongRunningCallable() {
        b1.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                CallableTask task = new CallableTask();
                manager.add(task);
                System.out.println(task + " added to the queue");
            }
        });
        b2.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                for(String result:manager.purge()) {
                    System.out.println(result);
                }
            }
        });
        b3.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                for(TaskItem<String, CallableTask> tt:manager) {
                    tt.task.id();
                }
                for(String result:manager.getResults()) {
                    System.out.println(result);
                }
            }
        });
        setLayout(new FlowLayout());
        add(b1);
        add(b2);
        add(b3);
    }
    public static void main(String[] args) {
        SwingConsole.run(new InterruptableLongRunningCallable(), 200, 150);
    }

}

　　通常你还需要一个带进度条的友好提示界面

package com.example.demo.swing;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.ProgressMonitor;
import javax.swing.SwingUtilities;

class MonitoredCallable implements Callable<String>{
    private static int counter = 0;
    private final int id = counter++;
    
    private final ProgressMonitor monitor;
    private static final int MAX = 8;
    
    public MonitoredCallable(ProgressMonitor monitor) {
        this.monitor = monitor;
        monitor.setNote(toString());
        monitor.setMaximum(MAX-1);
        monitor.setMillisToPopup(500);
    }
    

    @Override
    public String call() throws Exception {
        System.out.println(this + " stared");
        try {
            for(int i=0;i<MAX;i++) {
                TimeUnit.MILLISECONDS.sleep(500);
                if(monitor.isCanceled()) {
                    Thread.currentThread().interrupt();
                }
                final int progess = i;
                SwingUtilities.invokeLater(new Runnable() {
                    
                    @Override
                    public void run() {
                        monitor.setProgress(progess);
                    }
                });
            }
        }catch (Exception e) {
            monitor.close();
            System.out.println(this + " interrupted");
            return "Result: " + this + " interrupted";
        }
        System.out.println(this + " completed");
        return "Result: " + this + " completed";
    }
    
    @Override
    public String toString() {
        return "Task " + id;
    }
}

public class MonitoredLongRunningCallable extends JFrame{
    private JButton b1 = new JButton("Start Long Running Task");
    private JButton b2 = new JButton("End Long Running Task");
    private JButton b3 = new JButton("Get results");
    
    private TaskManager<String, MonitoredCallable> manager = new TaskManager<>();
    
    public MonitoredLongRunningCallable() {
        b1.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                MonitoredCallable task = new MonitoredCallable(new ProgressMonitor(MonitoredLongRunningCallable.this, "Long-Running Task", "", 0, 0));
                manager.add(task);
                System.out.println(task + " added to the queue");
            }
        });
        
        b2.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                for(String resutl:manager.purge()) {
                    System.out.println(resutl);
                }
            }
        });
        
        b3.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                for(String result:manager.getResults()) {
                    System.out.println(result);
                }
            }
        });
        setLayout(new FlowLayout());
        add(b1);
        add(b2);
        add(b3);
    }
    
    public static void main(String[] args) {
        SwingConsole.run(new MonitoredLongRunningCallable(), 200, 500);
    }
}

22.10.2 可视化线程机制

package com.example.demo.swing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.sql.Time;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import javax.swing.JFrame;
import javax.swing.JPanel;

class CBox extends JPanel implements Runnable{
    private int pause;
    private static Random rand = new Random();
    private Color color = new Color(0);
    
    public CBox(int pause) {
        this.pause = pause;
    }
    
    @Override
    protected void paintComponent(Graphics g) {
        g.setColor(color);
        Dimension s = getSize();
        g.fillRect(0, 0, s.width, s.height);
    }

    @Override
    public void run() {
        while(!Thread.interrupted()) {
            color = new Color(rand.nextInt(0xFFFFFF));
            repaint();
            try {
                TimeUnit.MILLISECONDS.sleep(pause);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    
}

public class ColorBoxes extends JFrame{
    private int grid = 12;
    private int pause = 50;
    private static ExecutorService exec = Executors.newCachedThreadPool();
    
    public void setUp() {
        setLayout(new GridLayout(grid,grid));
        for(int i=0;i<grid*grid;i++) {
            CBox cBox = new CBox(pause);
            add(cBox);
            exec.execute(cBox);
        }
    }
    
    public static void main(String[] args) {
        ColorBoxes boxes = new ColorBoxes();
        if(args.length>0) {
            boxes.grid = new Integer(args[0]);
        }
        if(args.length>1) {
            boxes.pause = new Integer(args[1]);
        }
        boxes.setUp();
        SwingConsole.run(boxes, 500, 400);
    }
}

22.11 可视化编程与JavaBean

　　Introspector(内省器)

package com.example.demo.swing;

import java.awt.BorderLayout;
import java.awt.Event;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.BeanInfo;
import java.beans.EventSetDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.MethodDescriptor;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.lang.reflect.WildcardType;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class BeanDumper extends JFrame{
    private JTextField query = new JTextField(20);
    private JTextArea results = new JTextArea();
    
    public void print(String s) {
        results.append(s+"\n");
    }
    
    public void dump(Class<?> bean) {
        results.setText("");
        BeanInfo bInfo = null;
        try {
            bInfo = Introspector.getBeanInfo(bean,Object.class);
        } catch (IntrospectionException e) {
            System.out.println("couldn‘t introspect " + bean.getName());
            e.printStackTrace();
            return;
        }
        for(PropertyDescriptor d:bInfo.getPropertyDescriptors()) {
            Class<?> p = d.getPropertyType();
            if(p==null) continue;
            System.out.println("property type: " + p.getName() + "property name: "+d.getName());
            Method readMethod = d.getReadMethod();
            if(readMethod!=null) {
                System.out.println("read method: "+readMethod);
            }
            Method writeMethod = d.getWriteMethod();
            if(writeMethod!=null) {
                System.out.println("write metho: "+writeMethod);
            }
            System.out.println("==============================");
        }
        System.out.println("public methods:");
        for(MethodDescriptor m:bInfo.getMethodDescriptors()) {
            System.out.println(m.getMethod().toString());
        }
        System.out.println("==============================");
        System.out.println("event support:");
        for(EventSetDescriptor e:bInfo.getEventSetDescriptors()) {
            System.out.println("Listener type: "+e.getListenerType().getName());
            for(Method lm:e.getListenerMethods()) {
                System.out.println("Listener method: "+lm.getName());
            }
            for(MethodDescriptor lm:e.getListenerMethodDescriptors()) {
                System.out.println("method descriptor: "+ lm.getMethod());
            }
            Method addListener = e.getAddListenerMethod();
            System.out.println("Add listener Method "+ addListener);
            Method removeListener = e.getRemoveListenerMethod();
            System.out.println("remove listener Method"+removeListener);
            System.out.println("==========================");
        }
    }
    
    class Dumper implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent e) {
            String name = query.getText();
            Class<?> c = null;
            try {
                c = Class.forName(name);
            } catch (ClassNotFoundException e1) {
                e1.printStackTrace();
                results.setText("couldn‘t find "+name);
                return;
            }
            dump(c);
        }
        
    }
    
    public BeanDumper() {
        JPanel panel = new JPanel();
        panel.setLayout(new FlowLayout());
        panel.add(new JLabel("Qualified bean name"));
        panel.add(query);
        add(BorderLayout.NORTH,panel);
        add(new JScrollPane(results));
        Dumper dumper = new Dumper();
        query.addActionListener(dumper);
        query.setText("com.example.demo.swing.Frog");
        dumper.actionPerformed(new ActionEvent(dumper, 0, ""));
    }
    
    public static void main(String[] args) {
        SwingConsole.run(new BeanDumper(), 600, 500);
    }
}

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