1.
import java.io.*;
public class Java_1 {
public static void main(String[ ] args) throws IOException {
InputStreamReader ir;
BufferedReader in;
int max, x;
String data;
max = 0;
ir = new InputStreamReader(System.in);
in = new BufferedReader(ir);
System.out.println("請輸入5個正整數：");
//*********Found**********
for (int i = 1; i<= 5; i++) {
data = in.readLine();
//*********Found**********
x = Integer.parseInt(data);
if ( max < x )
//*********Found**********
max = x;
}
System.out.println("輸入的最大值是 "+ max);
}
}
2.檔案的和遞迴呼叫
import java.io.File;
public class Java_2
{
public static void main(String s[])
{
//Getting the Current Working Directory
String curDir = System.getProperty("user.dir");
System.out.println("當前的工作目錄是:"+curDir);
//*********Found**********
File ff=new File(curDir);
String[] files=ff.list();
for(int i=0; i<files.length; i++)
{
String ss=curDir+"\\"+files[i];
traverse(0,ss);
}
}
/**
* 遞迴地遍歷目錄樹
* @param level 目錄的層次
* @param s 當前目錄路徑名
*/
public static void traverse(int level,String s)
{
File f=new File(s);
for(int i=0; i<level; i++) System.out.print(" ");
if(f.isFile())
{
System.out.println(f.getName());
}
else if(f.isDirectory())
{
//*********Found**********
System.out.println("<"+f.getName()+">");
String[] files=f.list();
level++;
//*********Found**********
for(int i=0; i<files.length;i++)
{
String ss=s+"\\"+files[i];
//*********Found**********
traverse(level,ss);
}
}
else
{
System.out.println("ERROR!");
}
}
}
3.swing構架與AWT事件處理機制
import java.awt.*;
import java.awt.event.*;
//*********Found**********
import javax.swing.*;
public class Java_3 {
public static void main(String[ ] args) {
JFrame frame = new JFrame("Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found**********
frame.getContentPane().add(new Change());
frame.pack();
frame.setVisible(true);
}
}
class Change extends JPanel {
int count = 200;
JLabel l1;
JButton b1, b2;
public Change( ) {
setPreferredSize(new Dimension(280, 60));
l1 = new JLabel("200");
b1 = new JButton("增大");
b2 = new JButton("減小");
add(l1);
//*********Found**********
add(b1);
//*********Found**********
add(b2);
b1.addActionListener( new BListener( ) );
b2.addActionListener( new BListener( ) );
}
//*********Found**********
private class BListener implements ActionListener {
//*********Found**********
public void actionPerformed (ActionEvent e) {
if (e.getSource( ) == b1) {
count++;
} else {
count--;
}
l1.setText("" + count);
}
}
}
二
1.考察JOptionPane類
import javax.swing.JOptionPane; //匯入JOptionPane類
public class Java_1 {
public static void main( String args[] )
{
//*********Found********
JOptionPane.showMessageDialog(
null, "歡迎\n你\n參加\nJava\n考試!" );
System.exit( 0 ); // 結束程式
}
}
/* JOptionPane類的常用靜態方法如下：
showInputDialog()
showConfirmDialog()
showMessageDialog()
showOptionDialog()
*/
2.
import java.util.Random;
public class Java_2
{
public static void main(String args[]){
Random random = new Random();
float x = random.nextFloat();//產生0.0與1.0之間的一個符點數
int n = Math.round(20*x); //構造20以內的一個整數
long f = 1 ; //儲存階乘的結果
int k = 1 ; //迴圈變數
//*********Found********
do{f = k * f;
k++;
//*********Found********
}while(k <= n);
System.out.println(n+"!= "+f);
}
}
3.
//考察對話方塊綜合使用，首先繼承JFrame類以及實現ActionListener介面。處理GUI事件；浮點輸出格式；//showMessageDialog()顯示資訊
import java.text.DecimalFormat;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//*********Found********
public class Java_3 extends JFrame implements ActionListener {
private JTextField input1, input2, output;
private int number1, number2;
private double result;
// 初始化
public Java_3()
{
//*********Found********
super( "示範異常" );
Container c = getContentPane();
c.setLayout( new GridLayout( 3, 2 ) );
c.add( new JLabel( "輸入分子",
SwingConstants.RIGHT ) );
input1 = new JTextField( 10 );
c.add( input1 );
c.add(
new JLabel( "輸入分母和回車",
SwingConstants.RIGHT ) );
input2 = new JTextField( 10 );
c.add( input2 );
input2.addActionListener( this );
c.add( new JLabel( "計算結果", SwingConstants.RIGHT ) );
output = new JTextField();
c.add( output );
setSize( 425, 100 );
show();
}
//處理 GUI 事件
public void actionPerformed( ActionEvent e )
{
DecimalFormat precision3 = new DecimalFormat( "0.000" );
output.setText( "" ); // 空的JTextField輸出
//*********Found********
try {
number1 = Integer.parseInt( input1.getText() );
number2 = Integer.parseInt( input2.getText() );
result = quotient( number1, number2 );
//*********Found********
output.setText(precision3.format(result));
}
catch ( NumberFormatException nfe ) {
JOptionPane.showMessageDialog( this,
"你必須輸入兩個整數",
"非法數字格式",
JOptionPane.ERROR_MESSAGE );
}
catch ( Exception dbze ) {
//*********Found********
JOptionPane.showMessageDialog( this,
"除法異常",
"除數為零",
JOptionPane.ERROR_MESSAGE );
}
}
// 定義求商的方法，如遇除數為零時，能丟擲異常。
public double quotient( int numerator, int denominator )
throws Exception
{
if ( denominator == 0 )
throw new Exception();
return ( double ) numerator / denominator;
}
public static void main( String args[] )
{
Java_3 app = new Java_3();
app.addWindowListener(
new WindowAdapter() {
public void windowClosing( WindowEvent e )
{
e.getWindow().dispose();
System.exit( 0 );
}
}
);
}
}
/* JOptionPane類的常用靜態方法如下：
showInputDialog()
showConfirmDialog()
showMessageDialog()
showOptionDialog()
*/
三
1.考察Applet使用
//*********Found********
import java.applet.*;
import java.awt.Graphics;
//*********Found********
public class Java_1 extends Applet {
public void paint( Graphics g )
{
//*********Found********
g.drawString( "歡迎你來參加Java 語言考試!", 25, 25 );
}
}
2.考察Applet編寫
import java.awt.*;
import java.applet.*;
//*********Found********
public class Java_2 extends Applet
{
TextArea outputArea;
public void init()
{
setLayout(new BorderLayout());
outputArea = new TextArea();
//*********Found********
add( outputArea );
// 計算0至10的階乘
for ( long i = 0; i <= 10; i++ )
//*********Found********
outputArea.append(i + "! = " + factorial(i)+ "\n" );
}
// 用遞迴定義階乘方法
public long factorial( long number )
{
if ( number <= 1 ) // 基本情況
return 1;
else
//*********Found********
return number * factorial( number - 1 );
}
}
3.考察Swing與AWT中事件處理
import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import javax.swing.*;
public class Java_3
{
public static void main(String[] args)
{
FontFrame frame = new FontFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
//*********Found********
class FontFrame extends JFrame
{
public FontFrame()
{
setTitle("沁園春.雪");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
FontPanel panel = new FontPanel();
Container contentPane = getContentPane();
//*********Found********
contentPane.add(panel);
}
public static final int DEFAULT_WIDTH = 300;
public static final int DEFAULT_HEIGHT = 200;
}
//*********Found********
class FontPanel extends JPanel
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
String message = "數風流人物，還看今朝！";
Font f = new Font("隸書", Font.BOLD, 24);
g2.setFont(f);
FontRenderContext context = g2.getFontRenderContext();
Rectangle2D bounds = f.getStringBounds(message, context);
double x = (getWidth() - bounds.getWidth()) / 2;
double y = (getHeight() - bounds.getHeight()) / 2;
double ascent = -bounds.getY();
double baseY = y + ascent;
g2.setPaint(Color.RED);
//*********Found********
g2.drawString(message, (int)x, (int)(baseY));
}
}
四．
1.
public class Java_1{
public static void main(String[] args){
//*********Found**********
int[] scores = {90,80,75,67,53};
int best = 0;
char grade;
// 找出這組成績中的最高分
//*********Found**********
for (int i=0;i <=4; i++){
//*********Found**********
if (scores[i] > best)
best = scores[i];
}
//求各分數的等級並顯示
for (int i=0; i<scores.length; i++){
if (scores[i] >= best - 10)
grade = 'A';
//*********Found**********
else if (scores[i] >= best - 20)
grade = 'B';
else if (scores[i] >= best - 30)
grade = 'C';
else if (scores[i] >= best - 40)
grade = 'D';
else
grade = 'F';
System.out.println("Student " + i + " score is " + scores[i] +
" and grade is " + grade);
}
}
}
2.
public class Java_2 {
public static void main(String[ ] args) {
Point pt;
//*********Found**********
pt = new Point(2, 3);
System.out.println(pt);
}
}
class Point {
//*********Found**********
private int x;
private int y;
//*********Found**********
public Point (int a, int b) {
x = a;
y = b;
}
int getX( ) {
return x;
}
int getY( ) {
return y;
}
void setX(int a) {
x = a;
}
void setY(int b) {
y = b;
}
//*********Found**********
public String toString ( ) {
return "( " + x + "," + y + " ) ";
}
}
3.
import java.awt.*;
import java.awt.event.*;
//*********Found**********
import javax.swing.*;
//*********Found**********
public class Java_3 extends JPanel{
private int counter = 0;
private JButton closeAllButton;
public Java_3() {
JButton newButton = new JButton("New");
//*********Found**********
add(newButton);
newButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent evt){
CloseFrame f = new CloseFrame();
counter++;
f.setTitle("窗體 " + counter);
f.setSize(200, 150);
f.setLocation(30 * counter, 30 * counter);
//*********Found**********
f.setVisible(true);
closeAllButton.addActionListener(f);
}
});
closeAllButton = new JButton("Close all");
add(closeAllButton);
}
public static void main(String[ ] args) {
JFrame frame = new JFrame();
frame.setTitle("多窗體測試");
frame.setSize(300, 200);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new Java_3());
frame.setVisible(true) ;
}
}
//*********Found**********
class CloseFrame extends JFrame implements ActionListener {
public void actionPerformed(ActionEvent evt) {
setVisible(false);
}
}
1.矩陣運算
public class Java_1 {
public static void main(String args[]) {
int a[][] = {{2, 3, 4}, {4, 6, 5}};
int b[][] = {{1, 5, 2, 8}, {5, 9, 10, -3}, {2, 7, -5, -18}};
int c[][] = new int[2][4];
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 4; j++) {
//*********Found********
c[i][j] = 0 ;
//*********Found********
for (int k = 0; k < 3; k++)
//*********Found********
c[i][j] += a[i][k]*b[k][j];
System.out.print(c[i][j] + " ");
}
System.out.println();
}
}
}