第十六周作业
本人學號：201771010138
姓名：鄒豐蔚
《面向對象程序設計（java）》第十六周學習總結
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：測試程序并進行代碼注釋。
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。
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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接口改造程序后：
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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 M {public static void main(String[] args){ Runnable r=new Lefthand();Runnable r1=new Righthand();Thread t=new Thread(r);Thread t1=new Thread(r1);t.start();t1.start();} }得出結果：
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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。
14-1.14-2.14-3：
BallComponent：
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package bounce;import java.awt.*; import java.util.*; import javax.swing.*;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<>();/** 向組件中添加一個球。*/public void add(Ball b){balls.add(b);}public void paintComponent(Graphics g){super.paintComponent(g); // 擦除背景Graphics2D g2 = (Graphics2D) g;for (Ball b : balls){g2.fill(b.getShape());}}public Dimension getPreferredSize() { return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT); } }?
BounceFrame：
package bounce;import java.awt.*; import java.awt.event.*; import javax.swing.*;public class Bounce {public static void main(String[] args){EventQueue.invokeLater(() -> {JFrame frame = new BounceFrame();frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);});} }/** 帶有球組件和按鈕的框架。*/ class BounceFrame extends JFrame {private BallComponent comp;public static final int STEPS = 1000;public static final int DELAY = 3;/*** 用顯示彈跳球和的組件構造框架*啟動和關閉按鈕**/public BounceFrame(){setTitle("Bounce");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();}/*** 將按鈕添加到容器中*按鈕標題* 按鈕的動作監聽器*/public void addButton(Container c, String title, ActionListener listener){JButton button = new JButton(title);c.add(button);button.addActionListener(listener);}/***向面板中添加一個彈跳球，使其彈跳1000次。*/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);}}catch (InterruptedException e){}} }Ball：
package bounce;import java.awt.geom.*;/*** 從長方形邊緣上移動和彈跳的球*/ 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;/*** 將球移動到下一個位置，如果球碰到其中一條邊，則反向移動*/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;}}/*** 獲取球在當前位置的形狀。*/public Ellipse2D getShape(){return new Ellipse2D.Double(x, y, XSIZE, YSIZE);} }?
14-4:
?BounceThread:
package bounceThread;import java.awt.*; import java.awt.event.*;import javax.swing.*;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);});} }class BounceFrame extends JFrame {private BallComponent comp;public static final int STEPS = 1000;public static final int DELAY = 5;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();}public void addButton(Container c, String title, ActionListener listener){JButton button = new JButton(title);c.add(button);button.addActionListener(listener);}public void addBall() /** 在畫布上添加一個彈跳球，并啟動一個線程使其運行*/{Ball ball = new Ball();comp.add(ball);Runnable r = () -> { try{ for (int i = 1; i <= STEPS; i++){ball.move(comp.getBounds());comp.repaint();Thread.sleep(DELAY);}}catch (InterruptedException e){}};Thread t = new Thread(r);t.start();} }得出結果：
測試程序3：分析以下程序運行結果并理解程序。
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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!");}}?
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測試程序4
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l?教材642頁程序模擬一個有若干賬戶的銀行，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。
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l?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；
UnsynchBankTest:
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package unsynch; /*** 當多個線程訪問一個數據結構時，這個程序顯示數據損壞。*/ 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();}} }Bank：
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package unsynch; import java.util.*; public class Bank {private final double[] accounts;/*** @參數n表示賬戶數量* @每個帳戶的初始余額*/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。* @從帳戶中調出參數* @向要轉賬的賬戶輸入參數* @要轉帳的金額*/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。* 返回總余額*/public double getTotalBalance(){double sum = 0;for (double a : accounts)sum += a;return sum;}/***獲取銀行中的帳戶編號.* 返回賬號*/public int size(){return accounts.length;} }得出結果：
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綜合編程練習
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編程練習1
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（1）?用戶信息輸入界面如下圖所示:
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（2）?用戶點擊提交按鈕時，用戶輸入信息顯示控制臺界面；
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（3）?用戶點擊重置按鈕后，清空用戶已輸入信息；
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（4）?點擊窗口關閉，程序退出。
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Main：
import java.awt.EventQueue;import javax.swing.JFrame;public class Mian {public static void main(String[] args) {EventQueue.invokeLater(() -> {demo page = new demo();});} }WinCenter：
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);} }Demo：
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; public class demo extends JFrame {public demo() {JPanel panel1 = new JPanel();panel1.setPreferredSize(new Dimension(700, 45));panel1.setLayout(new GridLayout(1, 4));JLabel label1 = new JLabel("Name:");JTextField j1 = new JTextField("");JLabel label2 = new JLabel("Qualification:");JComboBox<Object> j2 = new JComboBox<>();j2.addItem("Graduate");j2.addItem("Not Graduate");panel1.add(label1);panel1.add(j1);panel1.add(label2);panel1.add(j2);JPanel panel2 = new JPanel();panel2.setPreferredSize(new Dimension(700, 50));panel2.setLayout(new GridLayout(1, 4));JLabel label3 = new JLabel("Address:");JTextArea j3 = new JTextArea();JLabel label4 = new JLabel("Hobby:");JPanel p = new JPanel();p.setLayout(new GridLayout(3, 1));p.setBorder(BorderFactory.createLineBorder(null));JCheckBox c1 = new JCheckBox("Reading");JCheckBox c2 = new JCheckBox("Singing");JCheckBox c3 = new JCheckBox("Dancing");p.add(c1);p.add(c2);p.add(c3);panel2.add(label3);panel2.add(j3);panel2.add(label4);panel2.add(p);JPanel panel3 = new JPanel();panel3.setPreferredSize(new Dimension(700, 150));FlowLayout flowLayout1 = new FlowLayout(FlowLayout.LEFT, 20, 40);panel3.setLayout(flowLayout1);JLabel label5 = new JLabel("Sex:");JPanel p1 = new JPanel();p1.setLayout(new GridLayout(2,1));p1.setBorder(BorderFactory.createLineBorder(null));ButtonGroup bu = new ButtonGroup();JRadioButton jr1 = new JRadioButton("Male");JRadioButton jr2 = new JRadioButton("Female");bu.add(jr1);bu.add(jr2);p1.add(jr1);p1.add(jr2);panel3.add(label5);panel3.add(p1);add(panel1);add(panel2);add(panel3);JPanel panel4 = new JPanel();panel4.setPreferredSize(new Dimension(700, 150));JButton b1 = new JButton("Validate");panel4.add(b1);JButton b2 = new JButton("Reset");panel4.add(b2);add(panel4);FlowLayout flowLayout = new FlowLayout();this.setLayout(flowLayout);this.setTitle("Students Detail");this.setBounds(200, 200, 800, 400);this.setVisible(true);this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);b1.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {// TODO 自動生成的方法存根String xueli = j2.getSelectedItem().toString();System.out.println("Name:" + j1.getText());System.out.println("Qualification:" + xueli);String hobbystring = "Hobby:";if (c1.isSelected()) {hobbystring += "Reading";}if (c2.isSelected()) {hobbystring += "Singing";}if (c3.isSelected()) {hobbystring += "Dancing";}System.out.println("Address:" + j3.getText());if (jr1.isSelected()) {System.out.println("Sex:Male");}if (jr2.isSelected()) {System.out.println("Sex:Female");}System.out.println(hobbystring);}});b2.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {// TODO 自動生成的方法存根j1.setText(null);j3.setText(null);j2.setSelectedIndex(0);c1.setSelected(false);c2.setSelected(false);c3.setSelected(false);bu.clearSelection();}});}public static void main(String args[]) {new demo();}}得出結果：
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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。
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package demo;class Lefthand extends Thread {public void run() {for (int i = 1; i <= 5; i++) {System.out.println("左:"+i+" 你好!");try {sleep(300);} catch (InterruptedException e) {System.out.println("Lefthand error.");}}} }class Righthand extends Thread{public void run(){for (int i = 1; i <= 5; i++){System.out.println("右:"+i+" 你好!");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();} }得出結果：
完善實驗十五 GUI綜合編程練習程序。
?身份證：
package demo1;import java.awt.*; import javax.swing.*;public class ButtonTest {public static void main(String[] args) {EventQueue.invokeLater(() -> {JFrame frame = new Main();frame.setTitle("身份證");frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);});} } package demo1;import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; import java.io.FileNotFoundException; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Scanner; import java.awt.*; import javax.swing.*; import java.awt.event.*;public class Main extends JFrame {private static ArrayList<Student> studentlist;private static ArrayList<Student> list;private JPanel panel;private JPanel buttonPanel;private static final int DEFAULT_WITH = 600;private static final int DEFAULT_HEIGHT = 300;public Main() {studentlist = new ArrayList<>();Scanner scanner = new Scanner(System.in);File file = new File("C:\\Users\\ASUS\\Desktop\\身份證號.txt");try {FileInputStream fis = new FileInputStream(file);BufferedReader in = new BufferedReader(new InputStreamReader(fis));String temp = null;while ((temp = in.readLine()) != null) {Scanner linescanner = new Scanner(temp);linescanner.useDelimiter(" ");String name = linescanner.next();String number = linescanner.next();String sex = linescanner.next();String age = linescanner.next();String province = linescanner.nextLine();Student student = new Student();student.setName(name);student.setnumber(number);student.setsex(sex);int a = Integer.parseInt(age);student.setage(a);student.setprovince(province);studentlist.add(student);}} catch (FileNotFoundException e) {System.out.println("學生信息文件找不到");e.printStackTrace();} catch (IOException e) {System.out.println("學生信息文件讀取錯誤");e.printStackTrace();}panel = new JPanel();panel.setLayout(new BorderLayout());JTextArea jt = new JTextArea();panel.add(jt);add(panel, BorderLayout.NORTH);buttonPanel = new JPanel();buttonPanel.setLayout(new GridLayout(1, 7));JButton jButton = new JButton("名單");JButton jButton1 = new JButton("年齡");JLabel lab = new JLabel("省份");JTextField jt1 = new JTextField();JLabel lab1 = new JLabel("年齡：");JTextField jt2 = new JTextField();JLabel lab2 = new JLabel("輸入你的身份證號碼：");JTextField jt3 = new JTextField();JButton jButton2 = new JButton("退出");jButton.setBounds(110, 90, 60, 30);jButton1.setBounds(110, 90, 60, 30);jt1.setBounds(110, 90, 60, 30);jt2.setBounds(110, 90, 60, 30);jt3.setBounds(110, 90, 60, 30);jButton2.setBounds(110, 90, 60, 30);jButton.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {Collections.sort(studentlist);jt.setText(studentlist.toString());}});jButton1.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {int max = 0, min = 100;int j, k1 = 0, k2 = 0;for (int i = 1; i < studentlist.size(); i++) {j = studentlist.get(i).getage();if (j > max) {max = j;k1 = i;}if (j < min) {min = j;k2 = i;}}jt.setText("年齡最大：" + studentlist.get(k1) + "年齡最小：" + studentlist.get(k2));}});jButton2.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {dispose();System.exit(0);}});jt1.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {String find = jt1.getText();String text = "";String place = find.substring(0, 3);for (int i = 0; i < studentlist.size(); i++) {if (studentlist.get(i).getprovince().substring(1, 4).equals(place)) {text += "\n" + studentlist.get(i);jt.setText("老鄉：" + text);}}}});jt2.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {String yourage = jt2.getText();int a = Integer.parseInt(yourage);int near = agenear(a);int value = a - studentlist.get(near).getage();jt.setText("年齡相近：" + studentlist.get(near));}});jt3.addKeyListener(new KeyAdapter() {public void keyTyped(KeyEvent e) {list = new ArrayList<>();Collections.sort(studentlist);String key = jt3.getText();for (int i = 1; i < studentlist.size(); i++) {if (studentlist.get(i).getnumber().contains(key)) {list.add(studentlist.get(i));jt.setText（“\n" + list); }}}});buttonPanel.add(jButton);buttonPanel.add(jButton1);buttonPanel.add(lab);buttonPanel.add(jt1);buttonPanel.add(lab1);buttonPanel.add(jt2);buttonPanel.add(lab2);buttonPanel.add(jt3);buttonPanel.add(jButton2);add(buttonPanel, BorderLayout.SOUTH);setSize(DEFAULT_WITH, DEFAULT_HEIGHT);}public static int agenear(int age) {int min = 53, value = 0, k = 0;for (int i = 0; i < studentlist.size(); i++) {value = studentlist.get(i).getage() - age;if (value < 0)value = -value;if (value < min) {min = value;k = i;}}return k;}} package demo1;public class Student implements Comparable<Student> {private String name;private String number ;private String sex ;private int age;private String province;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getnumber() {return number;}public void setnumber(String number) {this.number = number;}public String getsex() {return sex ;}public void setsex(String sex ) {this.sex =sex ;}public int getage() {return age;}public void setage(int age) {// int a = Integer.parseInt(age);this.age= age;}public String getprovince() {return province;}public void setprovince(String province) {this.province=province ;}public int compareTo(Student o) {return this.name.compareTo(o.getName());}public String toString() {return name+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";} }計算器：
package T;import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.FileNotFoundException; import java.io.PrintWriter; import java.util.Collections; import java.util.Scanner;import javax.swing.*;import java.math.*;public class D extends JFrame {private String[] c=new String[10];private String[] c1=new String[11];private int[] list=new int[10];int i=0,i1=0,sum = 0;private PrintWriter out = null;private JTextArea text,text1;private int counter;public D() {JPanel Panel = new JPanel();Panel.setLayout(null);JLabel JLabel1=new JLabel("...");JLabel1.setBounds(500, 800, 400, 30);JLabel1.setFont(new Font("Courier",Font.PLAIN,35));JButton Button = new JButton("生成題目");Button.setBounds(50,150,150,50);Button.setFont(new Font("Courier",Font.PLAIN,20)); Button.addActionListener(new Action());JButton Button2 = new JButton("確定答案");Button2.setBounds(300,150,150,50);Button2.setFont(new Font("Courier",Font.PLAIN,20));Button2.addActionListener(new Action1());JButton Button3 = new JButton("讀出文件");Button3.setBounds(500,150,150,50);Button3.setFont(new Font("Courier",Font.PLAIN,20));Button3.addActionListener(new Action2());text=new JTextArea(30,80);text.setBounds(30, 50, 200, 50);text.setFont(new Font("Courier",Font.PLAIN,35));text1=new JTextArea(30,80);text1.setBounds(270, 50, 200, 50);text1.setFont(new Font("Courier",Font.PLAIN,35));Panel.add(text);Panel.add(text1);Panel.add(Button);Panel.add(Button2);Panel.add(Button3);Panel.add(JLabel1);add(Panel);}private class Action implements ActionListener{public void actionPerformed(ActionEvent event){ text1.setText("0");if(i<11) {int a = 1+(int)(Math.random() * 99);int b = 1+(int)(Math.random() * 99);int m= (int) Math.round(Math.random() * 3);switch(m){case 1:while(a<b){ b = (int) Math.round(Math.random() * 100);a = (int) Math.round(Math.random() * 100); } c[i]=((i+1)+":"+a+"/"+b+"=");list[(i+1)]=Math.floorDiv(a, b);text.setText((i+1)+":"+a+"/"+b+"=");i++;break; case 2:c[i]=((i+1)+":"+a+"*"+b+"=");list[(i+1)]=Math.multiplyExact(a, b);text.setText((i+1)+":"+a+"*"+b+"="); i++;break;case 3:c[i]=((i+1)+":"+a+"+"+b+"=");list[(i+1)]=Math.addExact(a, b);text.setText((i+1)+":"+a+"+"+b+"=");i++;break ;case 4:while(a<=b){ b = (int) Math.round(Math.random() * 100);a = (int) Math.round(Math.random() * 100); } c[i]=((i+1)+":"+a+"-"+b+"=");text.setText((i+1)+":"+a+"-"+b+"=");list[(i+1)]=Math.subtractExact(a, b);i++;break ;}}}} private class Action1 implements ActionListener{public void actionPerformed(ActionEvent event){ if(i<10) {String daan=text1.getText().toString().trim();int a = Integer.parseInt(daan);if(text1.getText()!=" ") {if(list[i1]==a) sum+=10;}c1[i1]=daan;i1++;}}} private class Action2 implements ActionListener{public void actionPerformed(ActionEvent event){try {out = new PrintWriter("text.txt");} catch (FileNotFoundException e) {e.printStackTrace();}for(int counter=0;counter<10;counter++){out.println(c[counter]+c1[counter]);}out.println("成績"+sum);out.close();}} } package T; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Toolkit;import javax.swing.JFrame;public class N {public static void main (String args[]){Toolkit t=Toolkit.getDefaultToolkit();Dimension s=t.getScreenSize(); EventQueue.invokeLater(() -> {JFrame frame = new D();frame.setBounds(0, 0,(int)s.getWidth()/2,(int)s.getHeight()/2);frame.setTitle(" ");frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);}); }}
實驗總結：
多線程的概念：
多線程是進程執行過程中產生的多條執行線索。
‐線程是比進程執行更小的單位。
線程不能獨立存在，必須存在于進程中，同一進
程的各線程間共享進程空間的數據。
‐每個線程有它自身的產生、存在和消亡的過程，
是一個動態的概念。
多線程意味著一個程序的多行語句可以看上去幾
乎在同一時間內同時運行。
‐線程創建、銷毀和切換的負荷遠小于進程，又稱
為輕量級進程（lightweight process）。
用Thread類的子類創建線程：
?首先需從Thread類派生出一個子類，在該子類中
重寫run()方法。
? 然后用創建該子類的對象
? 最后用start()方法啟動線程
用Thread類的子類創建多線程的關鍵性操作：
–定義Thread類的子類并實現用戶線程操作，即
run()方法的實現。
–在適當的時候啟動線程。
由于Java只支持單重繼承，用這種方法定義的類不
可再繼承其他父類。
用Runnable()接口實現線程：
? 首先設計一個實現Runnable接口的類；
? 然后在類中根據需要重寫run方法；
? 再創建該類對象，以此對象為參數建立Thread
類的對象；
? 調用Thread類對象的start方法啟動線程，將
CPU執行權轉交到run方法。
線程兩種創建方法比較：
實現Runnable接口的優勢：
?符合OO設計的思想
?便于用extends繼承其它類
? 采用繼承Thread類方法的優點：代碼簡單
? 提倡采用第一種方式
通過本周理論知識的學習以及在實驗課上所做的實驗，我掌握了線程的概念，也懂得了如何去理論線程的知識點在頁面布局管理器上編輯一些東西。
?
轉載于:https://www.cnblogs.com/siofer/p/10126809.html
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