java易考测试题及答案

public class TestBorderLayout { public static void main(String[] args) { Frame f = new Frame(\"Java Frame\"); Button btn1 = new Button(\"NORTH\"); Button btn2 = new Button(\"SOUTH\"); Button btn3 = new Button(\"EAST\"); Button btn4 = new Button(\"WEST\"); Button btn5 = new Button(\"CENTER\"); f.add(btn1,BorderLayout.NORTH); f.add(btn2,BorderLayout.SOUTH); f.add(btn3,BorderLayout.EAST); f.add(btn4,BorderLayout.WEST); f.add(btn5,BorderLayout.CENTER); f.setBounds(100,100,300,200); f.setVisible(true); } }

绘制一个圆，一个矩形。关闭窗口 uuimport java.awt.*; import java.awt.event.*;

public class TestPaint { public static void main(String[] args) { new PaintFrame().launchFrame(); } }

class PaintFrame extends Frame { public void launchFrame() { setBounds(200,200,640,480);

setVisible(true);

this.addWindowListener(new MyWindowMonitor()); } public void paint(Graphics g) { Color c = g.getColor(); g.setColor(Color.red); g.fillOval(50, 50, 30, 30); g.setColor(Color.green); g.fillRect(80,80,40,40); g.setColor(c); } class MyWindowMonitor extends WindowAdapter { public void windowClosing(WindowEvent e) { setVisible(false); System.exit(0); } } }

出现计算表格： + = import java.awt.*;

import java.awt.event.*;

public class TFMathTest extends Frame{ TextField num1; TextField num2; TextField sum; public static void main(String[] args) { new TFMathTest().launchFrame(); } public void launchFrame() { num1 = new TextField(); num2 = new TextField(); sum = new TextField(); num1.setColumns(10); num2.setColumns(10); sum.setColumns(15); setLayout(new FlowLayout()); //setSize(500, 30); Label lblPlus = new Label(\"+\"); Button btnEqual = new Button(\"=\");

btnEqual.addActionListener(new MyListener(this)); add(num1); add(lblPlus); add(num2); add(btnEqual); add(sum); pack(); setVisible(true); } }

class MyListener implements ActionListener { private TFMathTest tfmt; public MyListener(TFMathTest tfmt) { this.tfmt = tfmt; } public void actionPerformed(ActionEvent e) { String s1 = tfmt.num1.getText(); String s2 = tfmt.num2.getText(); int i1 = Integer.parseInt(s1); int i2 = Integer.parseInt(s2); tfmt.sum.setText(String.valueOf(i1 + i2)); } }

一个窗口，里边有个矩形框 import java.awt.*; public class TestPanel {

public static void main(String args[]) {

Frame f = new Frame(\"Java Frame with Panel\"); Panel p = new Panel(null); f.setLayout(null);

f.setBounds(300,300,500,500);

f.setBackground(new Color(0,0,102)); p.setBounds(50,50,400,400);

p.setBackground(new Color(204,204,255)); f.add(p);

f.setVisible(true); } }

一个窗口，中间矩形

import java.awt.*;

public class CenterPanel {

public static void main(String args[]) {

new MyFrame3(300,300,400,300,Color.BLUE); } }

class MyFrame3 extends Frame{ private Panel p;

MyFrame3(int x,int y,int w,int h,Color c){ super(\"FrameWithPanel\"); p = new Panel(null); setLayout(null); setBounds(x,y,w,h); setBackground(c);

p.setBounds(w/4,h/4,w/2,h/2);

p.setBackground(Color.YELLOW); add(p);

setVisible(true); } }

一个窗口分4份 import java.awt.*;

public class TestMultiFrame {

public static void main(String args[]) {

MF f1 = new MF(100,100,200,200,Color.BLUE); MF f2 = new MF(300,100,200,200,Color.YELLOW); MF f3 = new MF(100,300,200,200,Color.GREEN); MF f4 = new MF(300,300,200,200,Color.ORANGE); } }

class MF extends Frame{ static int id = 0;

MF(int x,int y,int w,int h,Color color){ super(\"MF \" + (++id)); setBackground(color); setLayout(null); setBounds(x,y,w,h); setVisible(true); } }

在输入框里打什么，就输出什么 import java.awt.*;

import java.awt.event.*;

public class TFActionEvent { public static void main(String[] args) { new TFFrame1(); } }

class TFFrame1 extends Frame { TFFrame1() { TextField tf = new TextField(); add(tf); tf.addActionListener(new TFActionListener()); pack(); setVisible(true); } }

class TFActionListener implements ActionListener { public void actionPerformed(ActionEvent e) { TextField tf = (TextField)e.getSource(); System.out.println(tf.getText()); tf.setText(\"\"); } }

事件处理，两个按钮，开始结束，在屏幕上显示开始结束 import java.awt.*;

import java.awt.event.*;

public class TestActionEvent2 {

public static void main(String args[]) { Frame f = new Frame(\"Test\"); Button b1 = new Button(\"Start\"); Button b2 = new Button(\"Stop\"); Monitor2 bh = new Monitor2(); b1.addActionListener(bh); b2.addActionListener(bh); b2.setActionCommand(\"game over\"); f.add(b1,\"North\"); f.add(b2,\"Center\"); f.pack(); f.setVisible(true); } }

class Monitor2 implements ActionListener {

public void actionPerformed(ActionEvent e) { System.out.println(\"a button has been pressed,\" + \"the relative info is:\\n \" + e.getActionCommand()); } }

计算圆的面积和正方形面积： abstract class Shape {

abstract public void area(); //abstract public void }

class Circle extends Shape {

double radius; public void area() {

System.out.println(\"圆形的面积为\"+3.14*2*radius*radius); }

public Circle(double r) {

radius =r; } }

class Square extends Shape {

double length; public void area() {

double areaa=length*length;

System.out.println(\"正方形的面积为\"+areaa); }

public Square(double l) {

length=l; } }

public class Showarea {

public static void main(String[] args) {

new Square(5).area(); new Circle(3).area(); }

}