java从入门到精通习题.docx

5.3public class Eval / 新建类public static void main(String args) / 主方法String regex = 135d9;String text =if (text.matches(regex) System.out.println(text + 是合法的手机号);5.4public class Eval / 新建类public static void main(String args) / 主方法StringBuilder builder = new StringBuilder(a);for (int i = 1; i = 10; i+) builder.append(i);System.out.println(builder.toString();6.1import java.util.*;public class Eval / 创建类public static void main(String args) int arr1=new int1,2,3,4,5; int arr2 = Arrays.copyOf(arr1, 3); / 复制源数组中从下标0开始的3个元素到目的数组，从下标0的位置开始存储。 for(int i=0;iarr1.length;i+) System.out.print(arr1i); System.out.println(); for(int j=0;jarr2.length;j+) System.out.print(arr2j);System.out.println();6.2import java.util.*;public class Eval / 创建类public static void main(String args) int arr = new int 10, 2, 3, 4, 5, 6, 7, 8, 9 ;Arrays.sort(arr);System.out.println(arr0);6.3import java.util.*;public class Text / 创建类public static void main(String args) String arr = new String ac, bc, dc, yc ;System.out.println(替换前：);for (String str : arr) System.out.print(str+t);Arrays.fill(arr, 2, 3, bb);System.out.println(n替换后：);for (String str2 : arr) System.out.print(str2+t);6.4public class Eval / 创建类public static void main(String args) int arr=new int1,2,3,4,5,6,7,8,9;System.out.println(数组原有内容：);for(int i = 0;iarr.length;i+)for(int j=0;jarr.length;j+)System.out.print(arrij);System.out.println();System.out.println(行列互换后数组内容：);for(int i = 0;iarr.length;i+)for(int j=0;jarr.length;j+)System.out.print(arrji);System.out.println();7.1package com.lzw;public class UseCase1 private String name;public String getName() return name;public void setName(String name) = name;/另一个java文件package com.lzw;public class UseCase2 extends UseCase1public static void main(String args) UseCase1 u=new UseCase1();u.setName(123);System.out.println(u.getName();7.2package com.lzw;public class UseCase3 private float height;private float width;public UseCase3(float height,float width)this.height=height;this.width=width;public float square()return height*width;public static void main(String args)UseCase3 u=new UseCase3(3.5f,4.5f);System.out.println(u.square();7.3package com.lzw;public class UseCase4 public static void main(String args) for(int i=0;iargs.length;i+)System.out.println(i);8.1public class Getintpublic static void main(String args) Integer inte = new Integer(452);int myint = Value();System.out.println(myint);8.2public class CharacterCompare public static void main(String args) Character char1 = new Character(h);Character char2 = new Character(H);boolean b = char1.equals(char2);System.out.println(b);Character char3 = char1.toLowerCase(char1);Character char4 = char2.toLowerCase(char2);boolean bb = char3.equals(char4);System.out.println(bb);8.3public class CreateBoolean public static void main(String args) Boolean b = new Boolean(ok);String str = b.toString();System.out.println(ok: + str);b = new Boolean(true);str = b.toString();System.out.println(true: + str);9.1package com.lzw;import java.util.*;public class RandomTest /*param args * 获取2到32之间的6个偶数，并且求这6个偶数的和 */public static double EvenNum(double num1,double num2)double s=0;int j=new int6;Random cres = new Random();for (int w = (int)num1,i=0; w = (int)num2; w += 2) ji = cres.nextInt(int) num2);if (ji!=0&ji % 2 = 0) System.out.println(ji);s += ji;i+;if(i=6) break;return s;public static double EvenNum2(double num1,double num2)double s=0;int j=new int6;for(int i=0,w=0;i20;i+)jw=(int)num1+(int)(Math.random()*(num2-num1);if (jw!=0&jw % 2 = 0) System.out.println(打印2到32之间的偶数(不包括32)+jw);s += jw;w+;if(w=6) break;return s;public static void main(String args) System.out.println(和为：+EvenNum2(2,32);9.2package com.lzw;import java.text.*;public class RoundArea static public void SimpleFormat(String pattern, double value) /使用实例化对象时设置格式化模式DecimalFormat myFormat = new DecimalFormat(pattern);/实例化DecimalFormat对象String output = myFormat.format(value);/将数字进行格式化System.out.println(value + + pattern + + output); public static double GetRoundArea(double r)return Math.PI*Math.pow(r, 2);public static void main(String args) System.out.print(圆的面积为：);SimpleFormat(#.#,GetRoundArea(2);9.3package com.lzw;import java.math.*;public class UseCase /* * param args */public static BigDecimal div(double value1,double value2,int b,int r)if(b 1000) throw new MyException(参数太大了); 12.2public class Brunt public static int count(int m,int n) return m * n; public static void main(String args) throws Exception try int result = count(12315,57876876); System.out.println(result); catch (Exception e) e.printStackTrace(); 12.3public class Computer public static int getMaxComm(int m , int n) throws MyException if( m = 0 |n=0) throw new MyException(传递的参数不是正整数); if(m n) int temp = 0; temp = m; m = n; n = temp; int r = m % n; while(r!=0) m = n; n = r; r = m % n; return n; public static void main(String args) try int m = 122 , n= 0;int reslut = getMaxComm(m,n);System.out.println(m+ 和 +n+的最大共约数是：+reslut); catch (MyException e) e.printStackTrace();/另一个类public class MyException extends Exception String message;public MyException(String ErrorMessagr) message = ErrorMessagr;public String getMessage()return message;13.1package com.lzw;import java.awt.*;import javax.swing.*;public class UseCase1 extends JFrame/* * */private static final long serialVersionUID = 1L;private JComboBox comboBox;public static void main(String args) new UseCase1();public UseCase1() super();setVisible(true);setSize(200,150);setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);comboBox = new JComboBox();comboBox.addItem(红);comboBox.addItem(黄);comboBox.addItem(蓝);comboBox.addItem(黑);getContentPane().add(comboBox, BorderLayout.NORTH);final JPanel panel = new JPanel();getContentPane().add(panel, BorderLayout.CENTER);final JCheckBox checkBox = new JCheckBox();checkBox.setText(男);panel.add(checkBox);final JCheckBox checkBox_1 = new JCheckBox();checkBox_1.setText(女);panel.add(checkBox_1);final JPanel panel_1 = new JPanel();getContentPane().add(panel_1, BorderLayout.SOUTH);final JButton okButton = new JButton();okButton.setText(确定);panel_1.add(okButton);final JButton button_1 = new JButton();button_1.setText(取消);panel_1.add(button_1);13.2package com.lzw;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class UseCase2 extends JFrame/* * */private static final long serialVersionUID = 1L;private String contents=列表1,列表2,列表3,列表4,列表5;private JComboBox jc=new JComboBox();private JButton jb=new JButton(提交);int count=0;public UseCase2() setSize(200, 100);setVisible(true);setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);Container cp=getContentPane();cp.setLayout(new FlowLayout();cp.add(jc);cp.add(jb);jb.addActionListener(new ActionListener()public void actionPerformed(ActionEvent arg0) if(countcontents.length)jc.addItem(contentscount+););public static void main(String args) new UseCase2();13.3package com.lzw;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class UseCase3 extends JFrame/* * */private static final long serialVersionUID = 1L;public UseCase3()setVisible(true);setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);setTitle(登录窗体);setBounds(300, 200, 300, 150);Container cp=getContentPane();cp.setLayout(null);JLabel jl=new JLabel(用户名：);jl.setBounds(10, 10, 200, 18);final JTextField name=new JTextField();name.setBounds(80, 10, 150, 18);JLabel jl2=new JLabel(密码：);jl2.setBounds(10, 50, 200, 18);final JPasswordField password=new JPasswordField();password.setBounds(80, 50, 150, 18);cp.add(jl);cp.add(name);cp.add(jl2);cp.add(password);JButton jb=new JButton(确定);jb.addActionListener(new ActionListener()public void actionPerformed(ActionEvent arg0) if(name.getText().trim().length()=0|new String(password.getPassword().trim().length()=0)JOptionPane.showMessageDialog(null, 用户名密码不允许为空);return;if(name.getText().trim().equals(mr)&new String(password.getPassword().trim().equals(mrsoft)JOptionPane.showMessageDialog(null, 登录成功);elseJOptionPane.showMessageDialog(null, 用户名或密码错误););jb.setBounds(80, 80, 60, 18);cp.add(jb);final JButton button = new JButton();button.setText(重置);button.addActionListener(new ActionListener()public void actionPerformed(ActionEvent arg0) / TODO 自动生成方法存根name.setText();password.setText(););button.setBounds(150, 80, 60, 18);getContentPane().add(button);public static void main(String args) new UseCase3();14.1import java.util.*;public class Text public static void main(String args) List list = new LinkedList();for(int i = 1 ;i=100;i+)list.add(new Integer(i);list.remove(list.get(10);System.out.println(ok);14.2import java.util.*;public class Text public static void main(String args) Set set = new HashSet(); /HashSet是Set的子接口 set.add(a); set.add(c); set.add(A); set.add(a); set.add(C); List list = new ArrayL