问答题 本题的功能是用文本框来设定表盘中指针的位置。窗口中有一个画板和两个文本框,画板中绘制了一个表盘和时针、分针,通过文本框分别设定“时”和“分”,表盘中的时针和分针就会指到对应的位置上。 import java.awt.*; import java.awt.event*; import java.awt.geom.*; import javax.swing.*; import javax.swing.event.*; public class java3 { public static void main(String[]args) { TextTestFrame frame=new TextTestFrame(): frame.setDefauhCloseOperation(JFrame.EXIT_ 0N_CLOSE); frame.show(); } } class TextTestFrame extends JFrame { public TextTestFrame() { setTitle("java3"): setSize(DEFAULT_WIDTH,DEFAULT_ HElGHT); Container contentPane=getContentPane(); DocumentListener listener=new DoeumentListen- er(); JPanel panel=new JPanel(); hourField=new JTextField("12",3); panel.add(hourField); hourField.getDocument().addDocumentListener (this); minuteField=new JTextField("00",3): panel.add(minuteField); minuteField.getDocument().addDocumentListener (listener);contentPane.add(panel,BorderLayout.S()UTH); clock=new ClockPanel(); contentPane.add(clock,BorderLayout.CEN- TER); } public void setClock() { try { int hours =Integer.parseInt(hourField.getText().trim ()): int minutes =Integer.parseInt(minuteField.getText().trim ()); clock.setTime(hours,minutes); } catch(NumberFormatExcepfion e){} } public static final int DEFAULT_WIDTH=300; public static final int DEFAULT_HEIGHT =300; private J TextField hourField; private JTextField minuteField; private ClockPanel clock; private class clockFieldListener extends Docu- mentListener { public void insertUpdate(DocumentEvent e){ set- Clock();} public void removeUpdate(DocumentEvent e){ setClock();} public void changedUpdate(DocumentEvent e){} } } class ClockPanel extends JPanel { pubhc void paintComponent(Graphics g) { super.paintComponent(g); Graphies2D g2=(Graphics2D)g; Ellipse2D circle =new Ellipse2D.Double(0,0,2* RADIUS,2 *RADIUS); g2.draw(circle); double hourAngle =Math.toRadians(90-360*minutes/(12 *60)); drawHand(92,hourAngle,HOUR_HAND_ LENGTH); double minuteAngle =Math.toRadians(90-360*minutes/60); drawHand(g2,minuteAngle,MINUTE_HAND_ LENGTH): } punic void drawHand(Graphics2D g2, double angle,double handLength) { Point2D end=new Point2D.Double( RADIUS+handLength*Math.cos(angle), RADIUS-handLength*Math.sin(angle)); Point2D center=new Point2D.Double(RADIUS, RADIUS): g2.draw(new Line2D.Double(center,end)); } public void setTime(int h,int m) { minutes=h*60+m; repaint(); } private double minutes=0; private double RADIUS=100; private double MINUTE_HAND_LENGTH= 0.8*RADIUS; private double HOUR_HAND_LENGTH=0.6 *RADIUS: }
问答题 本题利用递归方法求前n个自然数的和(n=lO)。 public class javal{ public static void main(String[]args){ int sum=add(10): System.out.println("1+2+…+9+10="+ sum); } public static int add( ){ if(n= =l){ ; } else ; } }
判断题 商业银行财务管理主要是指商业银行对各职能部门、分支机构的成本费用和利润进行控制考核,其目的降低整体经营成本、提高经济效益。