자바 프로 그래 밍 실 용 튜 토리 얼 (제4 판, 예 하 아) 시험 복습 문제 - 순 전 히 개인 사상

93、  ：   this   super    
this
1)     
2)         
3)           
super([    ])
1)    
2)      
94、  ：         
import java.util.Scanner;
public class JudgeLeepYear {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		System.out.println("     ：" + isLeepYear(sc.nextInt()));
	}
	public static boolean isLeepYear(int year) {
		return year % 400 == 0 || year % 100 != 0 && year % 4 == 0;
	}
}
95、  ： java.lang.Math   10 0-99       ，      。
public class GenerateRandom {
	public static void main(String[] args) {
		rand(10);
	}
	public static void rand(int number){
		for (int i = 0; i < number; i++) {
			System.out.print((int)(Math.random()*100)+" ");
		}
	}
}
96、  :   1+1/2！+1/3！+``````
import java.util.Scanner;
public class Factories {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int fact = 1;
		double sum = 0;
		for (int i = 1; i <= n; i++) {
			fact *= i;
			sum += 1.0 / fact;
		}
		System.out.println(sum);
	}
}
97、  ：      （   ：Rect），  ：①  protected    ，    ： 、 ；②      ：       ，      ；③    ：   area()、   perimeter() 
public class Rect {
	protected int width, height;
	public Rect(int width, int height) {
		this.width = width;
		this.height = height;
	}
	public Rect() {
		this(0, 0);
	}
	public int area() {
		return width * height;
	}
	public int perimeter() {
		return (width + height) * 2;
	}
}
98、  ：      （   ：Complex），  ：①  protected    ，    ：    、    ；②      ：       ，      ；③    ：      complexAdd(Complex a)  ，           、     a+bi       String toString( )  ；④ main( )                ：  complexAdd( )   1+2i  3+4i           4+6i，  toString( )            “4+6i”，   System.out.println( )        。
public class Complex {
	protected int real, imaging;
	public Complex() {
		this(0, 0);
	}
	public Complex(int real, int imaging) {
		this.real = real;
		this.imaging = imaging;
	}
	//     
	public void complexAdd(Complex a) {
		this.real += a.real;
		this.imaging += a.imaging;
	}
	public String toString() {
		return real + "+" + imaging + "i";
	}
	public static void main(String[] args) {
		Complex c1 = new Complex(1, 2);
		Complex c2 = new Complex(3, 4);
		c1.complexAdd(c2);
		System.out.println(c1.toString());//   4+6i
	}
}
99、  ：①          Frame          ；②      ；③    (200,200)、    (240,150)；④       ；⑤    、        ；⑥    ：  “Ok”  ，                       。
import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MyFrame extends Frame {
	private static final long serialVersionUID = 1L;
	private Button btn = null;
	private TextField text1 = null, text2 = null;
	public MyFrame() {
		super("    ！");
		this.setLocation(200, 200);
		this.setSize(240, 150);
		this.setLayout(new FlowLayout());
		this.add(new Label("   "));
		this.add(text1 = new TextField(20));
		this.add(new Label("   "));
		this.add(text2 = new TextField(20));
		this.add(btn = new Button("OK"));
		btn.addActionListener(new ActionListener() {
			//         
			public void actionPerformed(ActionEvent e) {
				String t1 = text1.getText();
				text2.setText(t1);
			}
		});
		this.setVisible(true);
	}
	public static void main(String[] args) {
		new MyFrame();
	}
}
100、  ：   TextArea            x,y          。
import java.awt.Frame;
import java.awt.TextArea;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
public class TextAreaSystem extends Frame implements WindowListener,
		MouseListener {
	private static final long serialVersionUID = 1L;
	private TextArea ta = null;
	private int x = 0, y = 0;
	private int click = 0, clicks = 0;//   1      
	public TextAreaSystem() {
		this.setBounds(100, 200, 300, 300);
		// new  
		ta = new TextArea();
		//     
		this.add(ta);
		// this.addMouseListener(this);//       
		ta.addMouseListener(this);
		this.addWindowListener(this);
		this.setVisible(true);
	}
	public static void main(String[] args) {
		new TextAreaSystem();
	}
	public void windowActivated(WindowEvent arg0) {//    
	}
	public void windowClosed(WindowEvent arg0) {//    
	}
	public void windowClosing(WindowEvent arg0) {
		System.out.println("x:" + x + " ,y:" + y);
		System.exit(0);
	}
	public void windowDeactivated(WindowEvent arg0) {//    
	}
	public void windowDeiconified(WindowEvent arg0) {//    
	}
	public void windowIconified(WindowEvent arg0) {//    
	}
	public void windowOpened(WindowEvent arg0) {//    
	}
	public void mouseClicked(MouseEvent arg0) {//   
		//          ，                    
		//   ：TextArea   Frame   ，   this    ，  x y    0，    
		x = arg0.getX();
		y = arg0.getY();
		if (arg0.getClickCount() > 1) {
			clicks++;//       
		} else {
			click++;//     
		}
		//     
		ta.setText("        : X-" + x + " , Y-" + y);
		ta.append("
     ：" + click);
		ta.append("
     ：" + clicks);
	}
	public void mouseEntered(MouseEvent arg0) {//    
	}
	public void mouseExited(MouseEvent arg0) {//    
	}
	public void mousePressed(MouseEvent arg0) {//    
	}
	public void mouseReleased(MouseEvent arg0) {
	}
}
101、  ：     /        ，                 ：①    Thread ；②  Runnable  
public class Test_Run {
	public Test_Run() {
		Thread o = new Odd();
		Thread e = new Thread(new Even());
		o.start();
		e.start();
	}
	public static void main(String[] args) {
		new Test_Run();
	}
	//    
	private class Odd extends Thread {
		public void run() {
			for (int i = 100; i < 200; i+=2) {
				System.out.print(i+" ");
			}
			System.out.println("
      ");
		}
	}
	//    
	private class Even implements Runnable {
		public void run() {
			for (int i = 201; i < 300; i+=2) {
				System.out.print(i+" ");
			}
			System.out.println("
      ");
		}
	}
}
102、  ：         ，         ，   12，   12      1、2、3、4、6、12
import java.util.Scanner;
public class Divisor {// Divisor  
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int factor = sc.nextInt();// factor  
		for (int i = 1; i <= factor; i++) {
			if (factor % i == 0) {
				System.out.print(i + " ");
			}
		}
	}
}
103、  ：     ， [1,1000]       3、5      。
public class DividedExactlyByThreeAndFive {
	public static void main(String[] args) {
		int count = 0;//           
		for (int i = 1; i <= 1000; i++) {
			if (i % 3 == 0 || i % 5 == 0) {
				count++;
				System.out.print(i + " ");
				if (count % 5 == 0) {
					System.out.println();
				}
			}
		}
	}
}
104、  ：            ，          5   ，       、   。
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class UserMaxMin extends JFrame implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton btnVerify = null;//     
	// textInput       ta           
	private JTextField textInput = null;
	private JTextArea ta = null;
	public UserMaxMin() {
		super("       ");
		this.setBounds(200, 100, 325, 300);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.getContentPane().setBackground(Color.cyan);
		this.setLayout(null);//     
		addModule();
		this.setVisible(true);
	}
	private void addModule() {
		// new   
		JLabel helpJLabel = new JLabel("  ：             “,”  。");
		JLabel inJLabel = new JLabel("   ：");
		textInput = new JTextField(20);
		ta = new JTextArea();
		btnVerify = new JButton("  ");
		//        
		helpJLabel.setBounds(20, 5, 300, 40);
		inJLabel.setBounds(20, 35, 100, 40);
		textInput.setBounds(70, 45, 220, 20);
		ta.setBounds(20, 80, 220, 100);
		btnVerify.setBounds(100, 200, 60, 40);
		// ta    
		ta.setEditable(false);
		ta.setText("   \t   ");
		ta.append("
0\t0");
		ta.append("
          ，
      。");
		// btnVerify   
		btnVerify.addActionListener(this);
		// this    
		this.getContentPane().add(helpJLabel);
		this.getContentPane().add(inJLabel);
		this.getContentPane().add(textInput);
		this.getContentPane().add(ta);
		this.getContentPane().add(btnVerify);
	}
	public void actionPerformed(ActionEvent arg0) {
		String s = textInput.getText();//      bug
		String[] strs = s.split(",");
		if (strs.length != 5) {
			JOptionPane.showConfirmDialog(this, "    ");
			return;
		}
		int max = Integer.MIN_VALUE;
		int min = Integer.MAX_VALUE;
		for (int i = 0; i < strs.length; i++) {
			int temp = Integer.parseInt(strs[i]);
			if (max < temp) {
				max = temp;
			}
			if (min > temp) {
				min = temp;
			}
		}
		ta.setEditable(false);
		ta.setText("   \t   ");
		ta.append("
" + max + "\t" + min);
		ta.append("
          ，
      。");
	}

	public static void main(String[] args) {
		new UserMaxMin();
	}
}
105、  ：        ，                      。
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class CopyFileChar {
	public static void main(String[] args) {
		//      ”         !!!“；               。
		copyFileFromByChar("d:/ex/a/", "fileStream.txt", "d:/ex/b/");//       
	}
	public static void copyFileFromByChar(String dirOld, String fileName,
			String dirNew) {
		FileReader fr = null;
		FileWriter fw = null;
		BufferedReader br = null;
		BufferedWriter bw = null;
		try {
			fr = new FileReader(dirOld + fileName);
			fw = new FileWriter(dirNew + fileName);
			br = new BufferedReader(fr);
			bw = new BufferedWriter(fw);
			while(true){
				String aline = null;
				try {
					aline = br.readLine();
					bw.write(aline);
					bw.newLine();
					bw.flush();
				} catch (Exception e) {
					break;
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {//            
			if (fr != null) {
				try {
					fr.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (br != null) {
				try {
					br.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (fw != null) {
				try {
					fw.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (bw != null) {
				try {
					bw.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
}
106、  ：              ，  “   Welcome you!”
import java.util.Scanner;
public class Welcom {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s+" Welcome you!");
	}
}
107、  ：          10   ，                。
import java.util.Scanner;
public class TenInt {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] mat = new int[10];
		for (int i = 0; i < mat.length; i++) {
			mat[i] = sc.nextInt();
		}
		for (int i = 0; i < mat.length-1; i++) {
			for (int j = i+1; j < mat.length; j++) {
				if(mat[i]= 1; i--) {//  
			for (int j = i; j <= 9; j++) {//  
				System.out.print(i + "*" + j + "=" + (i * j) + "\t");
			}
			System.out.println();
		}
	}
	public static void lowerTriangular() {//    
		for (int i = 1; i <= 9; i++) {//  
			for (int j = 1; j <= i; j++) {//  
				System.out.print(j + "*" + i + "=" + (i * j) + "\t");
			}
			System.out.println();
		}
	}
	public static void turnLlowerTriangular() {//    
		for (int i = 9; i >= 1; i--) {//  
			for (int j = 1; j <= i; j++) {//  
				System.out.print(j + "*" + i + "=" + (i * j) + "\t");
			}
			System.out.println();
		}
	}
}
110、           。
import java.util.Scanner;
public class Primer {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		System.out.println(isPrime(sc.nextInt()));
	}
	public static boolean isPrime(int prime) {
		if (prime == 2 || prime == 3 || prime == 5) {
			return true;
		}
		for (int i = 2; i * i <= prime; i++) {//   25=5*5,  5     。
			if (prime % i == 0) {
				return false;
			}
		}
		return true;
	}
}
111、  ：        ，                      。
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class CopyFile {
	public static void main(String[] args) {
		//      ”         !!!“；               。
		copyFileFrom("d:/ex/a/", "text.java", "d:/ex/b/");//       
	}
	public static void copyFileFrom(String dirOld, String fileName,
			String dirNew) {
		FileInputStream fin = null;
		FileOutputStream fout = null;
		try {
			fin = new FileInputStream(dirOld + fileName);
			byte[] buffer = new byte[512];
			fout = new FileOutputStream(dirNew + fileName);
			//           ，    。           ；      ，      。
			int count = 0;
			while ((count = fin.read(buffer)) > 0) {
				fout.write(buffer, 0, count);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {//            
			if (fin != null) {
				try {
					fin.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (fout != null) {
				try {
					fout.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
}