问答题 本题的功能是监听对于颜色的复制和粘贴。程序窗l:1中,有一个颜色设置框和两个按钮,名为“复制”和“粘贴”,在颜色设置框中设置颜色后,下面的预览面板将显示选中的颜色,单击“复制”按钮后,将设置的颜色复制到系统的剪贴板上,然后继续选择其他颜色,当单击按钮“粘贴”后预览面板的颜色将设置为刚才复制的颜色。 importjava.io.*; import java.awt.*; import java.awt.datatransfer.*; import java.awt.event.*; import java.awt.image.*; import javax.swing.*; public class java3 { public static void main(String[]args) { JFrame frame=new SerialTransferFrame(): frame.setDefaultCloseoperation(JFrame.EXIT ON_CLOSE); frame.show(); } } class SerialTransferFrame extends JFrame { public SerialTransferFrame() { setTitle("java3"): Container contentPane = getContentPane(); chooser=new JColorChooser(); contentPane.add(chooser,BorderLayout.CEN- TER); JPanel panel=new JPanel(); JButton copyButton=new JButton("复制"); panel.add(copyButton); copyButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { copy(); } }); JButton pasteButton=new JButton("粘贴"); panel.add(pasteButton); pasteButton.addAetionListener(new ActionListener() { public void aetionPerformed(AetionEvent event) { paste(); } }); contentPane.add(panel,BorderLayout.SOUTH); pack(); } private void copy() { Clipboard clipboard =Toolkit.getDefaultToolkit().getSystemClip- board(); int color=chooser.getColor(); SerialSeleetion selection=new SerialSelection (color); clipboard.setContents(selection,null); } private void paste() { Clipboard clipboard =Toolkit.getDefaultToolkit().getSystemClip- board(); Transferable contents=clipboard.getContents (null); if(contents= =null)return; try { DataFlavor flavor=new DataFlavor( "application/x-java-serialized-object;class= java.awt.Color"); if(contents.isDataFlavorSupported(flavor)) { Color color =(Color)contents.getTransferData(flavor); ; } } catch(ClassNotFoundException exception) { JOptionPane.showMessageDialog(this,excep- tion); } catch(UnsupportedFlavorException exception) { JOptionPane.showMessageDialog(this,excep- tion); } catch(IOException exception) { JOptionPane.showMessageDialog(this,excep- tion); } } private JColorChooser chooser; } class SerialSelection implements Transferable { SerialSelection(Serializable o) { obj=o: } public DataFlavor[]getTransferDataFlavors() { DataFlavor[]flavors=new DataFlavor[2]; Class type=obj.getClass(); String mimeType ="application/x-java-serialized-object;class =" +type.getName(); try { flavors[0]=new DataFlavor(mimeType); flavors[1]=DataFlavor.stringFlavor; return flavors; } catch(ClassNotFoundExeeption exception) { return new DataFlavor[O]; } } public boolean isDataFlavorSupported(DataFlavor flavor) { Return DataFlavor.stringFlavor.equals(flavor)‖"appli- cation".equals(flavor.getPrimaryType()) &&"x-iava-serialized-object".equals(flavor. getSubType()) &&flavor.getRepresentationClass().isAssign- ableFrom(obj.getClass()); } public void getTransferData(DataFlavor flavor) throws UnsupportedFlavorException { if(! isDataFlavorSupported(flavor)) throw new UnsupportedFlavorException(flaVor); if(DataFlavor.stringFlavor.equals(flavor)) return obj.toString(); return obj; } private Serializable obj; }
问答题 本题提取字符串“China is a great country.”中的前5个字符生成一个新的字符串,并将剩余字符组成另外一个新的字符串,最后将两个新的字符串连接输出。 public class javal{ public static void main(String[]args){ Stling str="China is a great country."; ; headstr=str.substring( ); trailstr=str.substring( ); System.out.println(headstr+trailstr); } }
判断题 房地产司法拍卖估价,评估的是市场价值,而房地产抵押估价,评估的应是谨慎价值。( )
问答题 本题是一个Applet,功能是用鼠标画不同颜色的图形。页面中有5个按钮“画红色图形”、“画绿色图形”、“画蓝色图形”、“橡皮”和“清除”,单击前三个按钮中的一个,按住鼠标左键或右键在面板中拖动,就能两出对应颜色的线条,单击“橡皮”按钮,按住鼠标左键或右键在面板中拖动就能将面板中的图形擦除掉,单击“清除”按钮,就能将面板中所有的图形清除掉。 import java.applet.*; import java.awt.*; import java.awt.event.*; public class java3 extends Applet implements ActionListener {int x=-1,y=-1,rubberNote=0,clearNote=0; Color C=new Color(255,0,O); int con=3; Button b_red,b_blue,b_green,b_clear,b_quit; public void init() { addMouseMotionListener(this); b_red=new Button("画红色图形"); b_blue=new Button("画蓝色图形"); b_green=new Button("画绿色图形"); b_quit=new Button("橡皮"); b_clear=new Button("清除"); add(b_red); add(b_green); add(b_blue); add(b_quit); add(b_clear); b_red.addActionListener(this); b_green.addActionListener(this); b_blue.addActionListener(this); b_quit.addActionListener(this); b_dear.addActionListener(this); } public void paint() (if(x!=-l&&y!=-l&rubberNote= = 0R&clearNote= =0) {g.setColor(c); g.filloval(X,Y,con,con); } else if(rubberNote= =1&&clearNote= =O) {g.clearRect(x,Y,10,10); } else if(clearNote= =1&&rubberNote= =O) {g.clearRect(0,0,getSize().width,getSize(). height); } } public void mouseDragged(MouseEvent e) {x=(int)e.getX();y=(int)e.getY();repaint(); } public void mouseMoved(MouseEvent e){) public void update(Graphics g) {paint(g); } public void actionPerformed(Event e) {if(e.getSource()= =b-red) {rubberNote=0;clearNote=0;c=new Color (255,0,0); } else if(e.getSource()= =b_green) {rubberNore=0;clearNote=0;C=new Color(0, 255,0); } else if(e.getSource()= =b_blue) {rubberNote=0;clearNote=0;C=new Color(0, 0,255); } if(e.getSource()= =b—quit) {rubberNote=1;clearNote=0; } if(e.getSource()= =b—clear) {clearNote=1;rubberNote=0;repaint(); } } }
问答题 本题的功能是通过鼠标确定两个点,然后画两点间的直线。窗口中有一个按钮“Draw line”,单击该按钮后,它就处于按下状态,然后用鼠标在窗口中单击一下,在单击的地方就会出现一个坐标圆点,用鼠标在另外一个地方单击一下又会出现另外一个圆点,并且此时在两个坐标圆点间画出一条直线,且“Draw line”处于可用状态,再单击这个按钮就可以画另外一条直线。 Import java.awt.* ; import java.awt.event.*; import javax.swing.*; class EventQueuePanel extends JPanel implements Ac- tionListener {EventQueuePanel() {JButton button=new JButton("Draw line"); add(button); button.addActionListener(this); } public void actionPerformed(ActionEvent evt) (Graphics g=getGraphics(); P=getClick(); g.drawOval(P.x-2,P.Y-2,4,4); Point q=getClick(); g.drawOval(q.x-2,q.y-2,4,4); g.drawLine(P.X,P.Y,q.x,q.y); g.dispose(); } public Point getClick() {EventQueue eq=Toolkit.getDefaultToolkit(). getSystemEventQueue(); while(true) {try {AWTEvent evt=eq.getNextEvent(); if(evt.getID()= =MouseEvent.MOUSE. PRESSED) {MouseEvent mevt=(MouseEvent)evt; Point P= (); Point top=getRootPane().getLocation(); P.X-=top.x; P.Y-=top.Y; return P; } } catch(InterruptedException e) {} } } private int Y=60; } class EventQueueFrame extends JFrame {public EventQueueFrame() {setTitle("java2"); setSize(300,200); addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {System.exit(0); } }); Container contentPane=getContentPane(); contentPane.add(new EventQueuePanel()); } } public class java2 {public static void main(String[]args) {Frame frame=new EventQueueFrame(); frame.show(); } }
判断题 合作游戏是指由教师建议或开始一个游戏,教师事先定好某些角色,以部分控制游戏的进行。()
问答题 本题中定义了一个树型的通信录,窗El左侧是一个树, 右侧是一个文本域,单击树的结点,则在右侧文本域中显示 相关信息,如果单击的是树结点,则显示对应名字的电话 信息。 import javax.swing.*; import javax.swing.tree.*; import java.awt.*; import java.awt.event.*; import javax.swing.event.*; class Mytree2 extends JFrame {JTree tree=null;JTextArea text=new JTextArea (20,20); Mytree2() {Container con=getContentPane(); DefauhMutableTreeNode root=new Default- MutableTreeNode("同学通信录"); DefaultMutableTreeNode tl=new Default- MutableTreeNode("大学同学"); DefaultMutableTreeNode t2=new Default- MutableTreeNode("研究生同学"); DefaultMutableTreeNode tl l=new Default- MutatleTreeNode("陈艳"); DefaultMutableTreeNode tl 2=new Default- MutableTreeNode("李小永"); DefaultMutableTreeNode t2 1=new Defauh- MutableTreeNode("王小小"); DefauhMutableTreeNode t2 2=new Defauh- MutableTreeNode("董小"); setTitle("java2"); root.add(t1);root.add(t2); tl.add(t1_1);tl.add(t1_2);t2.add(t2_1);t2. add(t2_2); tree=new JTree(root); JSerollPane scrollpane=new JScrollPane(text); JSplitPane splitpane=new JSplitPane(JSplitPane. HORIZONTAL SPLIT, true,tree,scrollpane); tree.addTreeSeleetionListener(this); con.add(splitpane); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) {System.exit(0);}}); setVisible(true);setBounds(70,80,200,300); } public void valueChanged(TreeSelectionEvent e) {if(e.getSouree()= =tree) {DefauhMutableTreeNode node= (DefaultMutableTreeNode)tree.getLastSelected- PathComponent(); if(node.isLeaf()) (String str= ; if(str.equals("陈艳")) (text.setText(str+":联系电话:0411- 4209876");} else if(str.equals("李小永")) {text.setText(str+":联系电话:010- 62789876");} else if(str.equals("王小小")) {text.setText(str+":联系电话:0430- 63596677");) else if(str.equals("董小")) {text.setText(str+":联系电话:020- 85192789");} } else {text.setText(node.getUserObject().toString ()); } } } } public class java2 {public static void main(String args[]) {Mytree2 win=new Mytree2();win.pack();} }
判断题 住房市场存在政府干预且受社会高度关注,除政府政策调整、社会舆论导向等的影响外,示范效应、从众心理等也会影响购买者决策,出现羊群效应等非理性购买行为。( )
问答题 本题中定义了长度为20的一维整型数组a,并将数组元素的下标值赋给数组元素,最后打印输出数组中下标为奇数的元素。 public class javal{ public static void main(String[]args){ int a[]= ; int i; for( ;i++) a[i]=i; for(i=0;i<20;i++){ if( ) System.OUt.print("a[It+i+"]="+a[i]+","); } } }
问答题 本题的功能是监听键盘键的敲击,并显示在窗口中。 import javax,.swing.*; importjava.awt.*; , import java.awt.event.*; public class java3 extends JFrame extends KeyListener { private String linel=""line2="" private String line3="" private JTextArea textArea; public java3() { super("java3"); textArea=new JTextArea(10,15); textArea.setText("Press any key on the key- board…"); textArea.setEnabled(false); addKeyListener(this); getContentPane().add(textArea); setSize(350,100); show(); } public void keyPressed(KeyEvent e) { linel="Key pressed:"+e.getKeyText(e. getKeyCode()); setLines2and3(e); } public void keyReleased(KeyEvent e) { linel="Key released:"+e.getKeyText(e. getKeyCode()); setLines2and3(e): } public void keyTyped(KeyEvent e) { Linel="Key typed:"+e.getKeychar(); setLines2and3(e); } private void setLines2and3(KeyEvent e) { line2="This key is"+(e.isActionKey()?"" :"not")+"an action key"; String temp=e.getKeyModifiersText(e.get- Modifiers()); hne3="Modifier keys pressed:"+(temp.e- quals("")?"none":temp); textArea.setText(linel+"\n"+line2+"\n" +line3+"\n"); } public static void main(String args[]) { java3 app=new java3(); addWindowListener(new Windowadapted() { public void windowClosing(WindowEvent e) { System.exit(0); } }); } }