201771010112羅松《面向對象程序設計（java）》第十六周學習總結
阿新 • • 發佈：2018-12-16
采集 paint 點擊 center page void radi flow 要求
1、實驗目的與要求
(1) 掌握線程概念；
(2) 掌握線程創建的兩種技術；
(3) 理解和掌握線程的優先級屬性及調度方法；
(4) 掌握線程同步的概念及實現技術；
2、實驗內容和步驟
實驗1：測試程序並進行代碼註釋。
測試程序1：
l 在elipse IDE中調試運行ThreadTest，結合程序運行結果理解程序；
l 掌握線程概念；
l 掌握用Thread的擴展類實現線程的方法；
l 利用Runnable接口改造程序，掌握用Runnable接口創建線程的方法。
class Lefthand extends Thread { public void run() {for(int i=0;i<=5;i++) { System.out.println("You are Students!"); try{ sleep(500); } catch(InterruptedException e) { System.out.println("Lefthand error.");} } } } class Righthand extends Thread { public void run() { for(int i=0;i<=5;i++) { System.out.println("I am a Teacher!"); try{ sleep(300); } catch(InterruptedException e) { System.out.println("Righthand error.");} } } } public class ThreadTest { static Lefthand left; static Righthand right;public static void main(String[] args) { left=new Lefthand(); right=new Righthand(); left.start(); right.start(); } }
利用Runnable接口改造程序修改後
class Lefthand implements Runnable { public void run() { for (int i = 0; i <= 5; i++) { System.out.println("You are Students!"); try { Thread.sleep(500); } catch (InterruptedException e) { System.out.println("Lefthand error."); } } } } class Righthand implements Runnable { public void run() { for (int i = 0; i <= 5; i++) { System.out.println("I am a Teacher!"); try { Thread.sleep(300); } catch (InterruptedException e) { System.out.println("Righthand error."); } } } } public class ThreadTest { public static void main(String[] args) { Runnable left = new Lefthand(); Thread a = new Thread(left); Runnable right = new Righthand(); Thread b = new Thread(right); a.start(); b.start(); } } ThreadTest
測試程序2：
l 在Elipse環境下調試教材625頁程序14-1、14-2 、14-3，結合程序運行結果理解程序；
l 在Elipse環境下調試教材631頁程序14-4，結合程序運行結果理解程序；
l 對比兩個程序，理解線程的概念和用途；
l 掌握線程創建的兩種技術。
（1） 在Elipse環境下調試教材625頁程序14-1、14-2 、14-3，結合程序運行結果理解程序；
package bounceThread; import java.awt.geom.*; /** A ball that moves and bounces off the edges of a rectangle * @version 1.33 2007-05-17 * @author Cay Horstmann */ public class Ball { private static final int XSIZE = 15; private static final int YSIZE = 15; private double x = 0; private double y = 0; private double dx = 1; private double dy = 1; /** Moves the ball to the next position, reversing direction if it hits one of the edges */ //定義了移動方法 public void move(Rectangle2D bounds) { x += dx; y += dy; if (x < bounds.getMinX()) { x = bounds.getMinX(); dx = -dx; } if (x + XSIZE >= bounds.getMaxX()) { x = bounds.getMaxX() - XSIZE; dx = -dx; } if (y < bounds.getMinY()) { y = bounds.getMinY(); dy = -dy; } if (y + YSIZE >= bounds.getMaxY()) { y = bounds.getMaxY() - YSIZE; dy = -dy; } } /** Gets the shape of the ball at its current position. */ //定義球外形 public Ellipse2D getShape() { return new Ellipse2D.Double(x, y, XSIZE, YSIZE); } } Ball Ball
package bounce; import java.awt.*; import java.util.*; import javax.swing.*; /** * The component that draws the balls. * @version 1.34 2012-01-26 * @author Cay Horstmann */ public class BallComponent extends JPanel { private static final int DEFAULT_WIDTH = 450; private static final int DEFAULT_HEIGHT = 350; private java.util.List<Ball> balls = new ArrayList<>(); /** * Add a ball to the component. * @param b the ball to add */ public void add(Ball b) { balls.add(b); } public void paintComponent(Graphics g) { super.paintComponent(g); // erase background Graphics2D g2 = (Graphics2D) g; for (Ball b : balls) { g2.fill(b.getShape()); } } public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); } } BallComponent BallComponent
package bounce; import java.awt.*; import java.awt.event.*; import javax.swing.*; /** * Shows an animated bouncing ball. * @version 1.34 2015-06-21 * @author Cay Horstmann */ public class Bounce { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new BounceFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } } /** * The frame with ball component and buttons. */ class BounceFrame extends JFrame { private BallComponent comp; public static final int STEPS = 1000; public static final int DELAY = 3; /** * Constructs the frame with the component for showing the bouncing ball and * Start and Close buttons */ public BounceFrame() { setTitle("Bounce"); comp = new BallComponent(); add(comp, BorderLayout.CENTER); JPanel buttonPanel = new JPanel(); addButton(buttonPanel, "Start", event -> addBall());//將按鈕放入buttonPanel addButton(buttonPanel, "Close", event -> System.exit(0)); add(buttonPanel, BorderLayout.SOUTH);//將buttonPanel放入邊界管理器的南端 pack(); } /** * Adds a button to a container. * @param c the container * @param title the button title * @param listener the action listener for the button */ public void addButton(Container c, String title, ActionListener listener) { //生成按鈕對象 JButton button = new JButton(title); c.add(button); button.addActionListener(listener);//註冊監聽器事件 } /** * Adds a bouncing ball to the panel and makes it bounce 1,000 times. */ public void addBall() { try { Ball ball = new Ball(); comp.add(ball); for (int i = 1; i <= STEPS; i++) { ball.move(comp.getBounds()); comp.paint(comp.getGraphics()); Thread.sleep(DELAY);//在兩個球顯示之間有延遲 } } catch (InterruptedException e)//中斷異常 { } } } Bounce Bounce
（2）在Elipse環境下調試教材631頁程序14-4，結合程序運行結果理解程序；
package bounceThread; import java.awt.*; import java.awt.event.*; import javax.swing.*; /** * 顯示動畫彈跳球 * @version 1.34 2015-06-21 * @author Cay Horstmann */ public class BounceThread { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new BounceFrame(); frame.setTitle("BounceThread"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } } /** * 框架與球組件和按鈕 */ class BounceFrame extends JFrame { private BallComponent comp; public static final int STEPS = 1000; public static final int DELAY = 5; /** * 用顯示彈跳球以及開始和關閉按鈕的組件構建框架 */ public BounceFrame() { comp = new BallComponent(); add(comp, BorderLayout.CENTER); JPanel buttonPanel = new JPanel(); addButton(buttonPanel, "Start", event -> addBall()); addButton(buttonPanel, "Close", event -> System.exit(0)); add(buttonPanel, BorderLayout.SOUTH); pack(); } /** * 向容器添加按鈕 * * @param c * the container * @param title * the button title * @param listener * the action listener for the button */ public void addButton(Container c, String title, ActionListener listener) { JButton button = new JButton(title); c.add(button); button.addActionListener(listener); } /** * 在畫布上添加一個彈跳球，並啟動一個線程使其彈跳 */ public void addBall() { Ball ball = new Ball(); comp.add(ball); Runnable r = () -> { try { for (int i = 1; i <= STEPS; i++) { ball.move(comp.getBounds());//將球移動到下一個位置，如果碰到其中一個邊緣則反轉方向 comp.repaint();//重繪此組件。 Thread.sleep(DELAY);//在指定的毫秒數內讓當前正在執行的線程休眠 } } catch (InterruptedException e) { } }; Thread t = new Thread(r); t.start(); } } BounceThread BounceThread
測試程序3：分析以下程序運行結果並理解程序。
class Race extends Thread { public static void main(String args[]) { Race[] runner=new Race[4]; for(int i=0;i<4;i++) runner[i]=new Race( ); for(int i=0;i<4;i++) runner[i].start( ); runner[1].setPriority(MIN_PRIORITY); runner[3].setPriority(MAX_PRIORITY);} public void run( ) { for(int i=0; i<1000000; i++); System.out.println(getName()+"線程的優先級是"+getPriority()+"已計算完畢!"); } }
測試程序4
l 教材642頁程序模擬一個有若幹賬戶的銀行，隨機地生成在這些賬戶之間轉移錢款的交易。每一個賬戶有一個線程。在每一筆交易中，會從線程所服務的賬戶中隨機轉移一定數目的錢款到另一個隨機賬戶。
在Elipse環境下調試教材642頁程序14-5、14-6，結合程序運行結果理解程序；
package unsynch; import java.util.*; /** * 有許多銀行賬戶的銀行 * @version 1.30 2004-08-01 * @author Cay Horstmann */ public class Bank { private final double[] accounts; /** * 建設銀行 * @param n 賬號 * @param initialBalance 每個賬戶的初始余額 */ public Bank(int n, double initialBalance) { accounts = new double[n]; Arrays.fill(accounts, initialBalance); } /** * 把錢從一個賬戶轉到另一個賬戶 * @param from 轉賬賬戶從 * @param to 轉賬賬戶到 * @param amount 轉讓的數額 */ public void transfer(int from, int to, double amount) { if (accounts[from] < amount) return; System.out.print(Thread.currentThread()); accounts[from] -= amount; System.out.printf(" %10.2f from %d to %d", amount, from, to); accounts[to] += amount; System.out.printf(" Total Balance: %10.2f%n", getTotalBalance()); } /** * 獲取所有帳戶余額的總和 * @return 總余額 */ public double getTotalBalance() { double sum = 0; for (double a : accounts) sum += a; return sum; } /** * 獲取銀行中的帳戶數量 * @return 賬號 */ public int size() { return accounts.length; } } Bank ank
package unsynch; /** * 此程序顯示多個線程訪問數據結構時的數據損壞 * @version 1.31 2015-06-21 * @author Cay Horstmann */ public class UnsynchBankTest { public static final int NACCOUNTS = 100; public static final double INITIAL_BALANCE = 1000; public static final double MAX_AMOUNT = 1000; public static final int DELAY = 10; public static void main(String[] args) { Bank bank = new Bank(NACCOUNTS, INITIAL_BALANCE); for (int i = 0; i < NACCOUNTS; i++) { int fromAccount = i; Runnable r = () -> { try { while (true) { int toAccount = (int) (bank.size() * Math.random()); double amount = MAX_AMOUNT * Math.random(); bank.transfer(fromAccount, toAccount, amount); Thread.sleep((int) (DELAY * Math.random())); } } catch (InterruptedException e) { } }; Thread t = new Thread(r); t.start(); } } } UnsynchBankTest UnsynchBankTest
綜合編程練習
編程練習1
1.設計一個用戶信息采集程序，要求如下：（1） 用戶信息輸入界面如下圖所示:
（1） 用戶點擊提交按鈕時，用戶輸入信息顯示控制臺界面；
（2） 用戶點擊重置按鈕後，清空用戶已輸入信息；
（3） 點擊窗口關閉，程序退出。
package AA; import java.awt.EventQueue; import javax.swing.JFrame; public class Main { public static void main(String[] args) { EventQueue.invokeLater(() -> { DemoJFrame page = new DemoJFrame(); }); } } Main Main
package AA; import java.awt.Dimension; import java.awt.Toolkit; import java.awt.Window; public class WinCenter { public static void center(Window win){ Toolkit tkit = Toolkit.getDefaultToolkit(); Dimension sSize = tkit.getScreenSize(); Dimension wSize = win.getSize(); if(wSize.height > sSize.height){ wSize.height = sSize.height; } if(wSize.width > sSize.width){ wSize.width = sSize.width; } win.setLocation((sSize.width - wSize.width)/ 2, (sSize.height - wSize.height)/ 2); } } WinCenter WinCenter
package o; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.GridLayout; import javax.swing.BorderFactory; import javax.swing.ButtonGroup; import javax.swing.JButton; import javax.swing.JCheckBox; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JRadioButton; import javax.swing.JTextField; public class DemoJFrame extends JFrame { private JPanel jPanel1; private JPanel jPanel2; private JPanel jPanel3; private JPanel jPanel4; private JTextField fieldname; private JComboBox comboBox; private JTextField fieldadress; private ButtonGroup bg; private JRadioButton Male; private JRadioButton Female; private JCheckBox read; private JCheckBox sing; private JCheckBox dance; public DemoJFrame() { // 設置窗口大小 this.setSize(800, 400); // 設置可見性 this.setVisible(true); // 設置標題 this.setTitle("編程練習一"); // 設置關閉操作 this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 設置窗口居中 WinCenter.center(this); // 創建四個面板對象 jPanel1 = new JPanel(); setJPanel1(jPanel1); jPanel2 = new JPanel(); setJPanel2(jPanel2); jPanel3 = new JPanel(); setJPanel3(jPanel3); jPanel4 = new JPanel(); setJPanel4(jPanel4); // 設置容器的為流布局 FlowLayout flowLayout = new FlowLayout(); this.setLayout(flowLayout); // 將四個面板添加到容器中 this.add(jPanel1); this.add(jPanel2); this.add(jPanel3); this.add(jPanel4); } /* * 設置面一 */ private void setJPanel1(JPanel jPanel) { // TODO 自動生成的方法存根 jPanel.setPreferredSize(new Dimension(700, 45)); // 給面板的布局設置為網格布局 一行4列 jPanel.setLayout(new GridLayout(1, 4)); JLabel name = new JLabel("name:"); name.setSize(100, 50); fieldname = new JTextField(""); fieldname.setSize(80, 20); JLabel study = new JLabel("qualification:"); comboBox = new JComboBox(); comboBox.addItem("初中"); comboBox.addItem("高中"); comboBox.addItem("本科"); jPanel.add(name); jPanel.add(fieldname); jPanel.add(study); jPanel.add(comboBox); } /* * 設置面板二 */ private void setJPanel2(JPanel jPanel) { // TODO 自動生成的方法存根 jPanel.setPreferredSize(new Dimension(700, 50)); // 給面板的布局設置為網格布局 一行4列 jPanel.setLayout(new GridLayout(1, 4)); JLabel name = new JLabel("address:"); fieldadress = new JTextField(); fieldadress.setPreferredSize(new Dimension(150, 50)); JLabel study = new JLabel("hobby:"); JPanel selectBox = new JPanel(); selectBox.setBorder(BorderFactory.createTitledBorder("")); selectBox.setLayout(new GridLayout(3, 1)); read = new JCheckBox("reading"); sing = new JCheckBox("singing"); dance = new JCheckBox("danceing"); selectBox.add(read); selectBox.add(sing); selectBox.add(dance); jPanel.add(name); jPanel.add(fieldadress); jPanel.add(study); jPanel.add(selectBox); } /* * 設置面板三 */ private void setJPanel3(JPanel jPanel) { // TODO 自動生成的方法存根 jPanel.setPreferredSize(new Dimension(700, 150)); FlowLayout flowLayout = new FlowLayout(FlowLayout.LEFT); jPanel.setLayout(flowLayout); JLabel sex = new JLabel("性別:"); JPanel selectBox = new JPanel(); selectBox.setBorder(BorderFactory.createTitledBorder("")); selectBox.setLayout(new GridLayout(2, 1)); bg = new ButtonGroup(); Male = new JRadioButton("male"); Female = new JRadioButton("female"); bg.add(Male ); bg.add(Female); selectBox.add(Male); selectBox.add(Female); jPanel.add(sex); jPanel.add(selectBox); } /* * 設置面板四 */ private void setJPanel4(JPanel jPanel) { // TODO 自動生成的方法存根 jPanel.setPreferredSize(new Dimension(700, 150)); FlowLayout flowLayout = new FlowLayout(FlowLayout.CENTER, 50, 10); jPanel.setLayout(flowLayout); jPanel.setLayout(flowLayout); JButton sublite = new JButton("提交"); JButton reset = new JButton("重置"); sublite.addActionListener((e) -> valiData()); reset.addActionListener((e) -> Reset()); jPanel.add(sublite); jPanel.add(reset); } /* * 提交數據 */ private void valiData() { // TODO 自動生成的方法存根 // 拿到數據 String name = fieldname.getText().toString().trim(); String xueli = comboBox.getSelectedItem().toString().trim(); String address = fieldadress.getText().toString().trim(); System.out.println(name); System.out.println(xueli); String hobbystring=""; if (read.isSelected()) { hobbystring+="reading "; } if (sing.isSelected()) { hobbystring+="singing "; } if (dance.isSelected()) { hobbystring+="dancing "; } System.out.println(address); if (Male.isSelected()) { System.out.println("male"); } if (Female.isSelected()) { System.out.println("female"); } System.out.println(hobbystring); } /* * 重置 */ private void Reset() { // TODO 自動生成的方法存根 fieldadress.setText(null); fieldname.setText(null); comboBox.setSelectedIndex(0); read.setSelected(false); sing.setSelected(false); dance.setSelected(false); bg.clearSelection(); } } DemoJFrame DemoJFrame
2．創建兩個線程，每個線程按順序輸出5次“你好”，每個“你好”要標明來自哪個線程及其順序號。
package BB; class xian1 extends Thread { public void run() { for(int i=1;i<=5;i++) { System.out.println( i+ "你好"+" 來自線程1"); try{ sleep(200); } catch(InterruptedException e)//異常捕獲 { System.out.println("Lefthand error.");} } } } class xian2 extends Thread { public void run() { for(int i=1;i<=5;i++) { System.out.println( i+ "你好"+" 來自線程2"); try{ sleep(200); } catch(InterruptedException e)//異常捕獲 { System.out.println("Lefthand error.");} } } } public class xiancheng { //屬性 static xian1 xian11; static xian2 xian22; public static void main(String[] args) { xian11=new xian1(); xian22=new xian2(); //用start（）方法啟動線程 xian11.start(); xian22.start(); } }
3. 完善實驗十五 GUI綜合編程練習程序。
3.實驗總結：
通過這次實驗，我大致掌握了線程的概念和線程創建的兩種技術，還大致理解和掌握了線程的優先級屬性及調度方法，但還有很多還有不太理解的地方，我會在之後的學習中慢慢去弄懂，總的來說這周學習比起前幾周來說還算順利，希望在之後的學習中能學到更多。
201771010112羅松《面向對象程序設計（java）》第十六周學習總結