Java期末整理.doc

Java期末复习汇总1键盘输入判断奇偶. package jxz;import java.io.*;public class panduan public static void main(String args) String s=;System.out.println(请输入数字);try/*大括号里面必考*/BufferedReader br=new BufferedReader(new InputStreamReader(System.in); s=br.readLine();catch(IOException e)int x=Integer.parseInt(s);if(x%2=0)System.out.println(even);elseSystem.out.println(odd);2.从文本框得到一个整数和如何关闭窗口 窗体的实现 标签按钮 课本177例题11-1：未做int数学 = Integer.parseInt(txt.getText(); /txt 为文本框3.加密：把字母改为往后四个数ch=str.char.Ati;ai=(char)ch+4;4.连接access数据库那几行代码public class Datebase public static void main(String args) String url = jdbc:odbc:Database1;try Class.forName(sun.jdbc.odbc.JdbcOdbcDriver); catch (java.lang.ClassNotFoundException e) System.err.println(e.getMessage();try Connection con = DriverManager.getConnection(url, , null);System.out.println(Connection succeed!);con.close(); catch (SQLException ex) System.out.println(Message: + ex.getMessage();5.输入流BufferedReader br=new BufferedReader(new InputStreamReader(System.in); s=br.readLine();6.student类有学号，姓名，年龄 存一个数组中public class student int number; String name; int age; int i; public student(int number,int age,String name) this.number=number; this.age=age; =name; public String toString() return 学号：+number+,年龄:+age+,姓名:+name; public static void main(String args) student s1=new student(1,18,张三); student s2=new student(4,22,李四); student s3=new student(7,21,王五); student s4=new student(3,26,马六); student s=s1,s2,s3,s4; System.out.println(班级人员名单：); for(int i=0;is.length;i+) System.out.println(si); for(int i=0;is.length;i+) si.age+; System.out.println(学生年龄加一后：); for(int i=0;is.length;i+) System.out.println(si); System.out.println(大于20岁的学生：); for(int i=0;i20) System.out.println(si); 7.定义接口实现面积方法 即定义接口Shape，其中包括一个方法size()，设计矩形，圆，圆柱体等尅类实现Shape接口，其size()方法表示计算矩形面积，圆面积，圆柱体体积。分别创建代表矩形，圆，圆柱体的3个对象存入一个Shape类型的数组中，并通过调用size()方法将数组中各类图形的大小输出。清单：package jxz;interface Shapedouble size();class Rectangle implements Shape private int x;private int y;public Rectangle(int x, int y) this.x = x;this.y = y;public double size()return x*y;class Circle implements Shapeprivate double r;public Circle(double r)this.r=r;public double size()return 3.14*r*r;class Cylinder implements Shapeprivate Circle c;private double h;public Cylinder(Circle c,double h)this.c=c;this.h=h;public double size()return c.size()*h;public class Java public static void main(String args)Shape s=new Shape3;s0=new Rectangle(5, 6);s1=new Circle(47);s2=new Cylinder(new Circle(20),5);for (int z=0;zs.length;z+)System.out.println(sz.size();8.输入一段字符串统计其中某个字母的个数本题以a为例package jxz;import java.io.*;public class dedao public static void main(String args) String s=;try/*大括号里面必考*/BufferedReader br=new BufferedReader(new InputStreamReader(System.in); s=br.readLine();catch(IOException e)int sum=0;for(int i=0;is.length();i+)char c=s.charAt(i);if(c=a)sum+;System.out.println(该字符串中的字母a出现的次数+sum);9. 此题和老师讲的稍微有些差距老师上课用的Scanner输入和ArrayList数组 我用的是流注意isDigit的地方从键盘输入若干行文字，最后输入的一行为”end”代表结束标记。(1) 统计该段文字中英文字母的个数。(2) 将其中的所有单词the全部改为a，输出结果。(3) 将该文字段所有的数字串找出来输出。清单：package jxz;import java.io.*;public class zftjpublic static void main(String args) throws IOExceptionint charnum=0,k=-1;boolean isDigit=false;StringBuffer digit=new StringBuffer();String a=;System.out.println(请输入若干行字符串，最后一行以end结束：);BufferedReader in=new BufferedReader(new InputStreamReader(System.in);String s=in.readLine();while(!s.equals(end)a+=s;s=new BufferedReader(new InputStreamReader(System.in).readLine();/统计中英文字母的个数for(int i=0;i=65&c=97&c=122) charnum+;System.out.println(您输入的字符串中字母的个数为：+charnum);/将单词the替换成a，并输出结果k=a.indexOf(the);if(k=-1) System.out.println(您输入的字符串中没有the子串。);elseSystem.out.println(将the替换成a后的字符串为：+a.replaceAll(the,a);/找出所有的数字串for(int i=0;ia.length();i+)char ch=a.charAt(i);if(Character.isDigit(ch)digit.append(ch);isDigit=true;elseif(isDigit)digit.append(,);isDigit=false;String x=digit.toString().split(,);System.out.println(共有+x.length+个数字串：);for(int n=0;nx.length;n+)System.out.print(xn+ );复习下 继承和多态 构造方法在类继承中的作用；方法的重载和方法的覆盖10.图形用户界面编程gbc.gridx = 3;gbc.gridy = 8;/这两行根据实际情况变化/*这三行为核心代码 网格块布局 需要有约束对象GridBagConstraints */GridBagLayout gb = new GridBagLayout();this.setLayout(gb);GridBagConstraints gbc = new GridBagConstraints();import java.awt.*;import java.awt.event.*;import java.sql.*;import javax.swing.*;public class zhuce extends JFrame implements ActionListener private JLabel lb1, lb2;/账号、密码private JTextField t1;/账号文本框private JPasswordField t2;/密码文本框private JButton b1, b2, b3;/确定、取消按钮public zhuce() super(用户注册);setSize(500,500);lb1 = new JLabel(账号);lb2 = new JLabel(密码);t1 = new JTextField(10);t2 = new JPasswordField(10);b1 = new JButton(确定);b2 = new JButton(取消);GridBagLayout gb = new GridBagLayout();this.setLayout(gb);GridBagConstraints gbc = new GridBagConstraints();gbc.gridx = 3;gbc.gridy = 8;gbc.gridwidth = 2;gbc.gridheight = 1;this.add(lb1, gbc);gbc.gridx = 5;gbc.gridy = 8;gbc.gridwidth = 8;gbc.gridheight = 1;this.add(t1, gbc);gbc.gridx = 3;gbc.gridy = 9;gbc.gridwidth = 2;gbc.gridheight = 1;this.add(lb2, gbc);gbc.gridx = 5;gbc.gridy = 9;gbc.gridwidth = 8;gbc.gridheight = 1;this.add(t2, gbc);gbc.gridx = 6;gbc.gridy = 10;gbc.gridwidth = 2;gbc.gridheight = 1;this.add(b1, gbc);gbc.gridx = 11;gbc.gridy = 10;gbc.gridwidth = 2;gbc.gridheight = 1;this.add(b