四则运算
1 package 小学四则运算; 2 3 import java.util.*; 4 5 //预计用时1个小时,开始于4.45,结束与5.30.实际用时45分钟 6 public class PrimaryOperation { 7 8 public static void main(String[] args) { 9 10 for (int i = 0; i <30; i++) { 11 12 int choice = (int)(Math.random()*5); 13 switch (choice) { 14 // + 15 case 0: 16 doAdd(i+1); 17 break; 18 // - 19 case 1: 20 doReduce(i+1); 21 break; 22 // * 23 case 2: 24 doMul(i+1); 25 break; 26 // / 27 case 3: 28 doDivide(i+1); 29 break; 30 } 31 } 32 } 33 // / 34 private static void doDivide(int i) { 35 System.out.println("第"+i+"次为:"); 36 37 int one=(int)(Math.random()*1000); 38 int two=(int)(Math.random()*1000); 39 40 System.out.println(one+"/"+two+"="+"\n\n"); 41 } 42 // * 43 private static void doMul(int i) { 44 System.out.println("第"+i+"次为:"); 45 int one=(int)(Math.random()*1000); 46 int two=(int)(Math.random()*1000); 47 System.out.println(one+"*"+two+"="+"\n\n"); 48 } 49 // - 50 private static void doReduce(int i) { 51 System.out.println("第"+i+"次为:"); 52 int one=(int)(Math.random()*1000); 53 int two=(int)(Math.random()*1000); 54 System.out.println(one+"-"+two+"="+"\n\n"); 55 56 } 57 // + 58 private static void doAdd(int i) { 59 System.out.println("第"+i+"次为:"); 60 int one=(int)(Math.random()*1000); 61 int two=(int)(Math.random()*1000); 62 System.out.println(one+"+"+two+"="+"\n\n"); 63 64 } 65 66 }
验证码
1 package 课堂测试3; 2 3 import java.util.Random; 4 import java.awt.Container; 5 import java.awt.Dimension; 6 import java.awt.FlowLayout; 7 8 import javax.swing.ImageIcon;//顶级容器即空白窗口 9 import javax.swing.JButton; 10 import javax.swing.JFrame; 11 import javax.swing.JLabel; 12 import javax.swing.JPanel; 13 import javax.swing.JPasswordField; 14 import javax.swing.JTextField; 15 16 public class Test { 17 18 public static void main(String[] args) { 19 Test t=new Test(); 20 t.set(); 21 22 } 23 24 private void set() { 25 JFrame f=new JFrame(); 26 f.setTitle("验证码");//窗口标题 27 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭 28 /* 29 * setDefaultCloseOperation() 30 * 设置默认的关闭窗口时的操作,取值为: 31 * DO_NOTHING_ON_CLOSE//小 32 * HIDE_ON_CLOSE 33 * DISPOSE_ON_CLOSE 34 * EXIT_ON_CLOSE 35 */ 36 f.setExtendedState(JFrame.MAXIMIZED_VERT);//最大化 37 /* 38 * setExtendedState() 39 * 设置扩展状态,取值为: 40 * NORMAL//小 41 * ICONIFIED//不弹出(运行),小 42 * MAXIMIZED_HORIZ//小 43 * MAXIMIZED_VERT//小 44 * MAXIMIZED_BOTH//全屏 45 */ 46 f.setSize(300,300);//窗口大小 47 48 /* 49 * 设置图标图像 50 * 图标:javax.swing.ImageIcon 51 * 图像:javax.awt.Image 52 * 创建图标:ImageIcon tu=new ImageIcon("图标位置"); 53 * 创建图像:Image image=new Image(); 54 * 设置:setIconImage(image); 55 */ 56 /* 57 * 添加标签 58 * JLabel yan=new JLabel("姓名"); 59 */ 60 Container con=f.getContentPane(); 61 JPanel pan=new JPanel(); 62 JLabel yan=new JLabel("验证码:"); 63 pan.add(yan); 64 JTextField yanzhengma=new JTextField(10); 65 pan.add(yanzhengma); 66 67 /* 68 * 随机字符,生成验证码 69 */ 70 71 String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; 72 Random random = new Random(); 73 StringBuffer yzm = new StringBuffer(); 74 75 for (int i = 0; i < 4; ++i) { 76 int number = random.nextInt(62);// [0,62) 77 yzm.append(str.charAt(number)); 78 } 79 String s=yzm.toString(); 80 JLabel ma=new JLabel(s); 81 pan.add(ma); 82 /* 83 * 按钮构造,类为JButten; 84 * 方法: 85 * JButton buttenOne=new JButton("确定"); 86 */ 87 JButton buttenOne=new JButton("确定"); 88 pan.add(buttenOne); 89 90 con.add(pan); 91 f.setVisible(true); 92 //窗口实现 93 } 94 }
在这两个小程序的编写中有很多方法的使用,以及新的Swing的各种方法
以后有的学了,