java简单计算机代码

⽤java代码写的简易计算器（可以实现基本的加减乘除功能）package A;import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import javax.swing.*;public class Calcular3 extends JFrame implements ActionListener,MouseListener{private int m1=0,n=0;//private double m2=0;//运算的数private int flag=0;JFrame f;JPanel p1,p2,p3;JTextField t;JButton b1[]=new JButton[18];String b[]= {"1","2","3","4","5","6","7","8","9","0","清空","退格",".","=","+","-","*","/"};public Calcular3(){f=new JFrame("计算器");t=new JTextField(35);p1=new JPanel();p2=new JPanel();p3=new JPanel();f.setBounds(100, 100, 400, 200);f.add(p1,BorderLayout.NORTH);f.add(p2,BorderLayout.CENTER);f.add(p3,BorderLayout.EAST);p2.setLayout(new GridLayout(5,3));p3.setLayout(new GridLayout(4,1));p1.add(t);for(int i=0;i<14;i++) {b1[i]=new JButton(b[i]);p2.add(b1[i]);b1[i].addActionListener(this);}for(int i=14;i<18;i++) {b1[i]=new JButton(b[i]);p3.add(b1[i]);b1[i].addActionListener(this);}/*for(int i=0;i<18;i++) {b1[i].addActionListener(this);}*/f.setVisible(true);}//实现接⼝的⽅法public void mouseClicked(MouseEvent e) {}public void mousePressed(MouseEvent e) {}public void mouseReleased(MouseEvent e) {}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void actionPerformed(ActionEvent e) {String str="";int i;for(i=0;i<=9;i++) {if(e.getSource()==b1[i]) {if(i==9) {n=n*10;}else {n=n*10+i+1;}str=String.valueOf(n);//整形n转换成字符串strt.setText(str);//显⽰到⽂本框上}}for(i=14;i<18;i++) {//+、-、*、/if(e.getSource()==b1[i]) {//匹配运算符m1=Integer.parseInt(t.getText());if(flag==15) {m2=m1+m2;}else if(flag==16) {m2=m1-m2;}else if(flag==17) {m2=m1*m2;}else if(flag==18) {m2=m1/m2;}else m2=m1;//若⽆连续的运算符运算，保存当前数据到m2 if(i==14) flag=15;else if(i==15) flag=16;else if(i==16) flag=17;else flag=18;str=String.valueOf(b[i]);t.setText(str);//显⽰到⽂本框上n=0;//还原，记录下次数据break;//找到匹配数据退出循环}}if(e.getSource()==b1[13]) {//=m1=Integer.parseInt(t.getText());if(flag==15) {m2=m2+m1;}else if(flag==16) {m2=m2-m1;}else if(flag==17) {m2=m2*m1;}else if(flag==18) {m2=m2/m1;}else m2=m1;str=String.valueOf(m2);t.setText(str);//显⽰到⽂本框上n=0;//还原，记录下次数据flag=0;//flag还原0，表明没有未处理的运算符}if(e.getSource()==b1[10]) {//各变量变为0 清空m1=0;m2=0;flag=0;n=0;t.setText("0");//显⽰到⽂本框上}if(e.getSource()==b1[11]) {//退格m1=(int)(Double.parseDouble(t.getText())/10);n=m1;str=String.valueOf(m1);t.setText(str);}if(e.getSource()==b1[12]) {//⼩数点m1=Integer.parseInt(t.getText());str=String.valueOf(m1+b[12]);t.setText(str);//显⽰到⽂本框上int j=0;for(i=0;i<=9;i++) {if(e.getSource()==b1[i]) {j++;m2=Math.pow(0.1, j)*Integer.parseInt(b[i]);str=String.valueOf(m1+m2);t.setText(str);//显⽰到⽂本框上}}}}//主函数public static void main(String[] args) {new Calcular3();}}。

//JSQ.javaimport java.awt.*;import java.awt.event.*;import javax.swing.*;public class JSQ{public static void main(String args[]){new MyJSQ("My计算器");}}class MyJSQ extends Frame implements ActionListener{JButton bOption,bNumber;TextField Tresult;int flag=0,perflag;//perflag表示单击了那一个运算符，1表示"+",2表示"-",3表示"*",4表示"/"double op1=0.0,op2=0.0;//操作数StringBuffer str=new StringBuffer();//显示屏所显示的字符串MyJSQ(String s){setTitle(s);Panel conPanel=new Panel();conPanel.setLayout(new BorderLayout());//设置显示屏Panel ptop=new Panel();Tresult=new TextField("0",20);Tresult.setEditable(false);//不可编辑性ptop.add(Tresult);conPanel.add(ptop,BorderLayout.NORTH);//总按键面板Panel pButton=new Panel();Cursor cs=Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);setCursor(cs);pButton.setLayout(new BorderLayout());//操作面板1Panel pUp=new Panel();pUp.setLayout(new GridLayout(2,5,1,1));//（行数，列数，水平间距，垂直间距)bOption=new JButton("x^3");bOption.setForeground(Color.gray);bOption.setMargin(new Insets(3,1,3,5));//setMargin()设置按钮边框和标签之间的空白。

import java.awt.*;import java.awt.event.*;import javax.swing.*;public class JiSuanQi extends JFrame implements ActionListener { private JPanel jp1, jp2, jp3, jp4;private JTextField shuru;private JButton n1, n2, n3, n4, n5, n6, n7, n8, n9, n0;private JButton jia, jian, cheng, chu, dian, deng;private JButton sqrt, pingfang, daoshu, baifenhao;private JButton qingchu, guiling, a, zhengfu;private boolean jiaf, jianf, chengf, chuf, end;private double num1, num2;Color c1 = Color.blue;Color c2 = Color.red;public JiSuanQi() {super("计算器-程鹏");n1 = new JButton("1");n1.setForeground(c1);n2 = new JButton("2");n2.setForeground(c1);n3 = new JButton("3");n3.setForeground(c1);n4 = new JButton("4");n4.setForeground(c1);n5 = new JButton("5");n5.setForeground(c1);n6 = new JButton("6");n6.setForeground(c1);n7 = new JButton("7");n7.setForeground(c1);n8 = new JButton("8");n8.setForeground(c1);n9 = new JButton("9");n9.setForeground(c1);n0 = new JButton("0");n0.setForeground(c1);jia = new JButton("+");jia.setForeground(c2);jian = new JButton("-");jian.setForeground(c2);cheng = new JButton("×");cheng.setForeground(c2);chu = new JButton("÷");chu.setForeground(c2);dian = new JButton(".");dian.setForeground(c2);deng = new JButton("=");deng.setForeground(c2);sqrt = new JButton("√");sqrt.setForeground(c2);pingfang = new JButton("x²");pingfang.setForeground(c2);daoshu = new JButton("1/x");daoshu.setForeground(c2);baifenhao = new JButton("%");baifenhao.setForeground(c2);a = new JButton();zhengfu = new JButton("±");a.setEnabled(false);qingchu = new JButton("Back");qingchu.setForeground(c2);guiling = new JButton("CE");guiling.setForeground(c2);shuru = new JTextField("0", 24);shuru.setHorizontalAlignment(JTextField.RIGHT); shuru.setEnabled(false);jp1 = new JPanel();jp1.setBackground(Color.LIGHT_GRAY);jp1.add(shuru);jp2 = new JPanel(null);jp2.setLayout(new GridLayout(4, 5, 10, 10));jp2.setBackground(Color.LIGHT_GRAY);jp2.add(n7);jp2.add(n8);jp2.add(n9);jp2.add(jia);jp2.add(sqrt);jp2.add(n4);jp2.add(n5);jp2.add(n6);jp2.add(jian);jp2.add(daoshu);jp2.add(n1);jp2.add(n2);jp2.add(n3);jp2.add(cheng);jp2.add(pingfang);jp2.add(dian);jp2.add(n0);jp2.add(deng);jp2.add(chu);jp2.add(baifenhao);n1.addActionListener(this);n2.addActionListener(this);n3.addActionListener(this);n4.addActionListener(this);n5.addActionListener(this);n6.addActionListener(this);n7.addActionListener(this);n8.addActionListener(this);n9.addActionListener(this);n0.addActionListener(this);jia.addActionListener(this);jian.addActionListener(this);cheng.addActionListener(this);chu.addActionListener(this);dian.addActionListener(this);deng.addActionListener(this);qingchu.addActionListener(this);guiling.addActionListener(this);shuru.addActionListener(this);sqrt.addActionListener(this);pingfang.addActionListener(this);daoshu.addActionListener(this);baifenhao.addActionListener(this);zhengfu.addActionListener(this);jp3 = new JPanel(new GridLayout(1, 4, 10, 20));jp3.setBackground(Color.LIGHT_GRAY);jp3.add(a);jp3.add(zhengfu);jp3.add(qingchu);jp3.add(guiling);jp4 = new JPanel(null);jp4.setLayout(new GridLayout(2, 1, 10, 40));jp4.setBackground(Color.LIGHT_GRAY);jp4.add(jp1);jp4.add(jp3);BorderLayout br = new BorderLayout(0, 20);this.setLayout(br);add(jp4, BorderLayout.NORTH);add(jp2, BorderLayout.CENTER);setResizable(true);setSize(330, 370);setLocation(500, 300);setVisible(true);}public void number(int i) {if (end) {shuru.setText("0");end = false;}String s;if (shuru.getText().trim().indexOf(".") != -1) {dian.setEnabled(false);} else {dian.setEnabled(true);}if (shuru.getText().equals("0") || shuru.getText().equals("+") || shuru.getText().equals("-") || shuru.getText().equals("×")|| shuru.getText().equals("÷")) {shuru.setText("");}s = String.valueOf(i);shuru.setText(shuru.getText() + s);}public void houtui(String s) {int n;n = s.length();shuru.setText(s.substring(0, n - 1));}public void yunsuan() {if (jiaf) {num1 = num1 + num2;} else if (chengf) {num1 = num1 * num2;} else if (chuf) {num1 = num1 / num2;} else if (jianf) {num1 = num1 - num2;} else {num1 = num2;}}public void clearPoint(double b) {String st = String.valueOf(b);if (st.endsWith(".0")) {int n = st.length();st = st.substring(0, n - 2);}shuru.setText(st);}public void actionPerformed(ActionEvent e) { String s = e.getActionCommand();if (s.equals("1")) {number(1);} else if (s.equals("2")) {number(2);} else if (s.equals("3")) {number(3);} else if (s.equals("4")) {number(4);} else if (s.equals("5")) {number(5);} else if (s.equals("6")) {number(6);} else if (s.equals("7")) {number(7);} else if (s.equals("8")) {number(8);} else if (s.equals("9")) {number(9);} else if (s.equals("0")) {number(0);} else if (s.equals("CE")) {shuru.setText("0");} else if (s.equals("Back")) {houtui(shuru.getText());} else if (s.equals("+")) {num1 = Double.parseDouble(shuru.getText());shuru.setText("+");jiaf = true;jianf = false;chengf = false;chuf = false;} else if (s.equals("-")) {num1 = Double.parseDouble(shuru.getText());shuru.setText("-");jianf = true;jiaf = false;chengf = false;chuf = false;} else if (s.equals("×")) {num1 = Double.parseDouble(shuru.getText());shuru.setText("×");chengf = true;jiaf = false;jianf = false;chuf = false;} else if (s.equals("÷")) {num1 = Double.parseDouble(shuru.getText());shuru.setText("÷");chuf = true;jiaf = false;jianf = false;chengf = false;} else if (s.equals("=")) {num2 = Double.parseDouble(shuru.getText());yunsuan();clearPoint(num1);chuf = false;jiaf = false;jianf = false;chengf = false;end = true;} else if (s.equals(".")) {String st;st = shuru.getText() + ".";shuru.setText(st);} else if (s.equals("√")) {num1 = Double.parseDouble(shuru.getText());double b = Math.sqrt(num1);clearPoint(b);end = true;} else if (s.equals("x²")) {num1 = Double.parseDouble(shuru.getText());double b = Math.pow(num1, 2);clearPoint(b);end = true;} else if (s.equals("1/x")) {num1 = Double.parseDouble(shuru.getText());double b = 1 / num1;clearPoint(b);end = true;} else if (s.equals("%")) {num1 = Double.parseDouble(shuru.getText());double b = num1 / 100;clearPoint(b);end = true;} else if (s.equals("±")) {double m= Double.parseDouble(shuru.getText());if (String.valueOf(m).equals("0")) {shuru.setText("");}String st=("" +(-m));m=Double.parseDouble(st);clearPoint(m);}}public static void main(String[] args) {JiSuanQi jsq = new JiSuanQi();}}。

JAVA简易计算器程序源代码package myText;import java.awt.*;import javax.swing.*;import java.awt.event.*;import javax.swing.border.*;public class Calculator extends JFrame implements ActionListener{ private JPanel Panel1=new JPanel();private JPanel Panel2=new JPanel();private JTextField tfResult=new JTextField(25);private JLabel label=new JLabel("计算结果:");private String recentOperation=null;private String recentNum=null;private boolean isNew=true;public void addButton(Container c,String s){JButton b=new JButton(s);b.setFont(new java.awt.Font("SansSerif",0,12));b.setForeground(Color.red);b.setBorder(BorderFactory.createRaisedBevelBorder());c.add(b);b.addActionListener(this);}//end public void addButton(Container c,String s)public void actionPerformed(ActionEvent e){String s=e.getActionCommand();if(s.charAt(0)>='0'&&s.charAt(0)<='9'){if(!isNew){tfResult.setText(tfResult.getText()+s);}//end if(!isNew)else{tfResult.setText(s);}//end elseisNew=false;}//end if(s.charAt(0)>='0'&&s.charAt(0)<='9') else if(s.equals(".")){if(tfResult.getText().indexOf(".")!=-1)return;if(!isNew&&tfResult.getText()!=""){tfResult.setText(tfResult.getText()+".");}//end ifelse{tfResult.setText("0.");}//end elseisNew=false;}//end if(s.equals("."))else if(s.equals("=")){equalaction(e);}//end if(s.equals("="))else{if((tfResult.getText()).equals("")){return;}//endif((tfResult.getText()).equals(""))if(recentOperation!=null){equalaction(e);}//end if(recentOperation!=null) recentOperation=s;recentNum=tfResult.getText();isNew=true;}//end else}//end public void actionPerformed(ActionEvent e) void equalaction(ActionEvent e){if(recentOperation==null||recentNum==null||tfResult.getTex t().equals("")){ return;}//end if()double last=0,now=0;try{last=Double.parseDouble(recentNum);now=Double.parseDouble(tfResult.getText());}//end trycatch(NumberFormatException ne){recentOperation=null;recentNum=null;tfResult.setText("数据输入不合法");System.out.println("数据输入不合法");isNew=true;return;}//end catch(NumberFormatException ne)if(recentOperation.equals("+")){last+=now;}//end if(recentOperation.equals("+"))if(recentOperation.equals("-")){last-=now;}//endif(recentOperation.equals("-"))if(recentOperation.equals("*")){last*=now;}//endif(recentOperation.equals("*"))if(recentOperation.equals("/")){last/=now;}//endif(recentOperation.equals("/"))tfResult.setText(""+last);recentNum=tfResult.getText();recentOperation=null;isNew=true;}//end void equalaction(ActionEvent e)public Calculator(){tfResult.setBorder(BorderFactory.createLoweredBevelBorder ());tfResult.setEditable(false);tfResult.setText("0");tfResult.setHorizontalAlignment(SwingConstants.RIGHT);////本java源代码由839682048整理修改//////Panel1.add(label,FlowLayout.LEFT);Panel1.add(tfResult);////本java源代码由839682048整理修改///Panel2.setLayout(new GridLayout(4,4,2,2));String buttons="789/456*123-0.=+";for(int i=0;i<buttons.length();i++){< p="">addButton(Panel2,buttons.substring(i,i+1));}//end for()//本java源代码由839682048整理修改///this.getContentPane().add(Panel1,"North");this.getContentPane().add(Panel2,"Center");this.setResizable(false);this.setTitle("计算器");this.addWindowListener(newjava.awt.event.WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}//end public Calculator1()public static void main(String[]args){Calculator mf=new Calculator();mf.setBounds(200,200,400,400);mf.show();}//end main()}//end public class Calculator1extends JFrame implements ActionListener</buttons.length();i++){<>。

简单计算器代码package calcultorthree;import java.awt.BorderLayout;//导入边界布局管理器类import java.awt.GridLayout;//导入网格布局管理器类import java.awt.TextField;//导入文本区域类import java.awt.event.ActionEvent;//导入事件类import java.awt.event.ActionListener;//导入事件监听者类import javax.swing.JButton;//导入按钮类import javax.swing.JFrame;//导入窗体import javax.swing.JPanel;//导入面板/***本例实现了简单计算器代码，具备加减乘除和正弦功能，旨在抱砖引玉。

熟悉java的同学，可以在此基础上实现更复杂的功能。

* @author Fjsh*/public class CalcultorThree {//新建对象，在构造函数中进行初始化JFrame frame;//新建窗体对象JButton buttonzero,buttondot,buttonequal;//新建按钮“0”“.”“=”JButton buttonplus,buttonminus,buttonmultiple,buttondevision,buttonsin,buttontozero;//新建按钮“+”“-”“*”“/”“sin”和归零按钮JButton buttonone,buttontwo,buttonthree,buttonfour,buttonfive,buttonsix,buttonseven,buttoneight,buttonnine;//新建数字按钮“0”“1”“2”“3”“4”“5”“6”“7”“8”“9”JPanel panelwest,panelcenter,paneleast;//新建三个面板TextField tf;//新建文本区域对象public CalcultorThree(){//初始化对象tf=new TextField(30);//构造空文本字段，字符宽度为30frame =new JFrame("CalculatorThree");//构造窗体对象，名称为“CalculatorThree”panelcenter=new JPanel();//构造面板，放到窗体中央panelwest=new JPanel();//构造面板，放到窗体西边paneleast=new JPanel();//构造面板，放到窗体东边Handle h=new Handle();//新建Handle类对象，Handle类为事件监听类//创建数字按钮对象，1、2、3、4、5、6、7、8、9buttonone=new JButton("1");buttontwo=new JButton("2");buttonthree=new JButton("3");buttonfour=new JButton("4");buttonfive=new JButton("5");buttonsix=new JButton("6");buttonseven=new JButton("7");buttoneight=new JButton("8");buttonnine=new JButton("9");panelcenter.setLayout(new GridLayout(3,3));//设置面板布局为网格布局，3行3列//将数字按钮添加到中间面板panelcenter.add(buttonone);panelcenter.add(buttontwo);panelcenter.add(buttonthree);panelcenter.add(buttonfour);panelcenter.add(buttonfive);panelcenter.add(buttonsix);panelcenter.add(buttonseven);panelcenter.add(buttoneight);panelcenter.add(buttonnine);//为10个按钮注册事件监听器buttonone.addActionListener(h);buttontwo.addActionListener(h);buttonthree.addActionListener(h);buttonfour.addActionListener(h);buttonfive.addActionListener(h);buttonsix.addActionListener(h);buttonseven.addActionListener(h);buttoneight.addActionListener(h);buttonnine.addActionListener(h);//构造按钮“0”“.”“=”，注册事件监听器，设置1行3列的布局，添加到到西边的面板buttonzero=new JButton("0");buttondot=new JButton(".");buttonequal=new JButton("=");buttonzero.addActionListener(h);buttondot.addActionListener(h);buttonequal.addActionListener(h);panelwest.setLayout(new GridLayout(3,1));panelwest.add(buttonzero);panelwest.add(buttondot);panelwest.add(buttonequal);//构造操作按钮“+”“-”“*”“/”“sin”“>0”，其中“>0”为归零按钮buttonplus=new JButton("+");buttonminus=new JButton("-");buttonmultiple=new JButton("*");buttondevision=new JButton("/");buttonsin=new JButton("sin");buttontozero=new JButton(">0");paneleast.setLayout(new GridLayout(3,1));//设置西边的布局为3行1列//将操作按钮“+”“-”“*”“/”“sin”“>0”添加到西边的面板中paneleast.add(buttonplus);paneleast.add(buttonminus);paneleast.add(buttonmultiple);paneleast.add(buttondevision);paneleast.add(buttonsin);paneleast.add(buttontozero);//为操作按钮“+”“-”“*”“/”“sin”“>0”注册监听器buttonplus.addActionListener(h);buttonminus.addActionListener(h);buttonmultiple.addActionListener(h);buttondevision.addActionListener(h);buttonsin.addActionListener(h);buttontozero.addActionListener(h);frame.setLayout(new BorderLayout());//设置窗体为边界布局frame.add(paneleast,"East");//将东边面板paneleast添加到窗体的东边frame.add(tf,BorderLayout.NORTH); //将tf文本区域添加到窗体的北边，即顶部frame.add(panelwest,BorderLayout.WEST);//将panelwest面板添加到窗体西边frame.add(panelcenter,BorderLayout.CENTER);//将panelcenter面板添加到窗体中间frame.pack();//设置窗体大小，适合其子组件的首选大小和布局frame.setLocation(500,500);//设置窗体显示位置为（500,500）frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置布局窗体默认关闭方式frame.setVisible(true);//设置窗体可见}public static void main(String[] args) {new CalcultorThree();//主方法中新建对象}class Handle implements ActionListener{//实现动作监听器类int biaozhi=0;//此标志标志加减乘除操作double flag1=0,flag2=0,flag3=0;//flag1、flag2为两个操作数，flag3为结果@Overridepublic void actionPerformed(ActionEvent e) { //方法重写try{//此处可能会产生异常，用try、catch捕捉异常，不用处理if(e.getSource()==buttondot){//小数点tf.setText("0.");}if(e.getSource()==buttontozero){//归零操作tf.setText("");}if(e.getSource()==buttonzero){//按键0操作tf.setText(tf.getText()+"0");flag1=Double.parseDouble(tf.getText());//将文本区域转换成Double类型，赋给flag1}if(e.getSource()==buttonone){//按键1操作tf.setText(tf.getText()+"1");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttontwo){//按键2操作tf.setText(tf.getText()+"2");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonthree){//按键3操作tf.setText(tf.getText()+"3");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonfour){//按键4操作tf.setText(tf.getText()+"4");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonfive){//按键5操作tf.setText(tf.getText()+"5");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonsix){//按键6操作tf.setText(tf.getText()+"6");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonseven){//按键7操作tf.setText(tf.getText()+"7");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttoneight){//按键8操作tf.setText(tf.getText()+"8");flag1=Double.parseDouble(tf.getText());}else if(e.getSource()==buttonnine){//按键9操作tf.setText(tf.getText()+"9");flag1=Double.parseDouble(tf.getText());}if(e.getSource()==buttonplus){//加法操作tf.setText("");flag2=flag1;biaozhi=0;}if(e.getSource()==buttonminus){//减法操作tf.setText("");flag2=flag1;biaozhi=1;}if(e.getSource()==buttonmultiple){//乘法操作tf.setText("");flag2=flag1;biaozhi=2;}if(e.getSource()==buttondevision){//除法操作tf.setText("");flag2=flag1;biaozhi=3;}if(e.getSource()==buttonsin){//正弦操作flag3=Math.sin(flag1);tf.setText(flag3+"");}if(e.getSource()==buttonequal){//等号操作，利用biaozhi判断进行相应加减乘除操作if(biaozhi==0){flag3=flag1+flag2;}if(biaozhi==1){flag3=flag1-flag2;}if(biaozhi==2){flag3=flag1*flag2;}if(biaozhi==3){flag3=flag1/flag2;}tf.setText(flag3+"");}}catch(Exception ex){}}}}。

简单的java代码简单的java代码Java是一种面向对象的编程语言，它具有简单、可移植、安全和高性能等特点。

在Java中，我们可以编写各种各样的代码，从简单的“Hello World”程序到复杂的企业级应用程序都可以使用Java来实现。

在本文中，我们将介绍一些简单的Java代码示例。

一、Hello World程序“Hello World”程序是任何编程语言中最基本和最常见的程序之一。

在Java中，我们可以使用以下代码来实现：```public class HelloWorld {public static void main(String[] args) {System.out.println("Hello, World!");}}```这个程序很简单，它定义了一个名为“HelloWorld”的类，并在其中定义了一个名为“main”的方法。

该方法通过调用System.out.println()方法来输出“Hello, World!”字符串。

二、计算两个数之和下面是一个简单的Java程序，用于计算两个数之和：```import java.util.Scanner;public class AddTwoNumbers {public static void main(String[] args) {int num1, num2, sum;Scanner input = new Scanner(System.in);System.out.print("Enter first number: ");num1 = input.nextInt();System.out.print("Enter second number: ");num2 = input.nextInt();sum = num1 + num2;System.out.println("Sum of the two numbers is " + sum); }}该程序首先导入了java.util.Scanner类，以便从控制台读取输入。

package caculator;import java.awt.Color;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.*;public class caculator extends JFrame implements ActionListener { double sum=0;static double getValue;static int action ;int i=0,j=0,p=0,l;double par1;JButton Jk=new JButton("k");JButton J1 = new JButton("1");JButton J2 = new JButton("2");JButton J3 = new JButton("3");JButton J4 = new JButton("4");JButton J5 = new JButton("5");JButton J6 = new JButton("6");JButton J7 = new JButton("7");JButton J8 = new JButton("8");JButton J9 = new JButton("9");JButton J0 = new JButton("0");JButton Je = new JButton("=");JButton Ja = new JButton("+");JButton Jr = new JButton("-");JButton Jm = new JButton("*");JButton Jd = new JButton("/");JButton Jc = new JButton("清除");JButton Jpt = new JButton(".");JTextArea show = new JTextArea("");caculator(){super("caculator");setLocation(200,200);setSize(300,350);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setVisible(true);JPanel jp = new JPanel();jp.setLayout(null);jp.add(J1);jp.add(J2);jp.add(J3);jp.add(J4);jp.add(J5);jp.add(J6);jp.add(J7);jp.add(J8);jp.add(J9);jp.add(J0);jp.add(Je);jp.add(Ja);jp.add(Jr);jp.add(Jm);jp.add(Jd);jp.add(Jc);jp.add(Je);jp.add(Jpt);J9.setBackground(Color.pink); J8.setBackground(Color.pink); J7.setBackground(Color.pink); J6.setBackground(Color.pink); J5.setBackground(Color.pink); J4.setBackground(Color.pink); J3.setBackground(Color.pink); J2.setBackground(Color.pink); J1.setBackground(Color.pink); J0.setBackground(Color.pink);Je.setBackground(Color.pink);Ja.setBackground(Color.pink); Jr.setBackground(Color.pink); Jm.setBackground(Color.pink); Jd.setBackground(Color.pink); Jc.setBackground(Color.pink); Jpt.setBackground(Color.pink);J7.setBounds(10,70,60,50);J8.setBounds(75,70,60,50);J9.setBounds(140,70,60,50); J4.setBounds(10,125,60,50); J5.setBounds(75,125,60,50); J6.setBounds(140,125,60,50); J1.setBounds(10,180,60,50); J2.setBounds(75,180,60,50); J3.setBounds(140,180,60,50); J0.setBounds(10,235,60,50); Je.setBounds(75,235,60,50); Jpt.setBounds(140,235,60,50);Jd.setBounds(205,70,60,50); Jm.setBounds(205,125,60,50); Jr.setBounds(205,180,60,50); Ja.setBounds(205,235,60,50); Jc.setBounds(205,10,60,50);J1.addActionListener(this);J2.addActionListener(this);J3.addActionListener(this);J4.addActionListener(this);J5.addActionListener(this);J6.addActionListener(this);J7.addActionListener(this);J8.addActionListener(this);J9.addActionListener(this);J0.addActionListener(this);Ja.addActionListener(this);Jr.addActionListener(this);Jm.addActionListener(this);Je.addActionListener(this);Jc.addActionListener(this);Jpt.addActionListener(this);jp.add(show);show.setBackground(Color.pink);show.setBounds(10,10,180,50);setContentPane(jp);}@Overridepublic void actionPerformed(ActionEvent e) { if(e.getSource()==J0){show.setText("0"); }if(e.getSource()==J1){show.setText("1");}if(e.getSource()==J2){show.setText("2");}if(e.getSource()==J3){show.setText("3");}if(e.getSource()==J4){show.setText("4");}if(e.getSource()==J5){show.setText("5");}if(e.getSource()==J6){show.setText("6");}if(e.getSource()==J7){show.setText("7");}if(e.getSource()==J8){show.setText("8");}if(e.getSource()==J9){show.setText("9");}par1=Double.parseDouble(show.getText()); if(e.getSource()==Ja){show.setText("");if(j==0){sum=par1;}else if(action==1){sum+=par1;}setsum();j++;p=0;i=0;action = 1;} if(e.getSource()==Jr){show.setText("");if(j==0){sum=par1;}else if(action==2){sum-=par1;}setsum();j++;p=0;i=0;action = 2;}if(e.getSource()==Jm){show.setText(""); if(j==0){sum=par1;}else if(action==3){sum*=par1;}setsum();j++;p=0;i=0;action = 3;}if(e.getSource()==Jd){show.setText(""); if(j==0){sum=par1;}else if(action==4){sum/=par1;}setsum();j++;p=0;i=0;action = 4;if(e.getSource()==Jc){clear();}if(e.getSource()==Jpt){show.append(".");}if(e.getSource()==Je){switch(action){case 1:show.setText(String.valueOf(sum+=par1)); break;case 2:show.setText(String.valueOf(sum-=par1)); break;case 3:show.setText(String.valueOf(sum*=par1)); break;case 4:show.setText(String.valueOf(sum/=par1)); break;}i=0;j=0;action=0;}}private void setsum() {show.setText(String.valueOf(sum));String s=show.getText();}void clear(){i=0;j=0;p=0;sum=0;action=0;show.setText("0"); }// TODO Auto-generated method stubpublic static void main(String args[]){caculator ct=new caculator();}}。

cmd写简短java代码
以下是一个简短的Java 代码片段，你可以在命令提示符（cmd）中使用javac编译器编译，并使用java命令运行：
1.创建Java 源代码文件：在文本编辑器中创建一个名为
HelloWorld.java的文件，内容如下：
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
2.打开命令提示符：打开命令提示符（cmd）。

3.切换到代码文件所在的目录：使用cd命令切换到存放
HelloWorld.java文件的目录。

例如：
cd path\to\your\directory
4.编译Java 代码：使用javac命令编译Java 代码：
javac HelloWorld.java
如果编译成功，将生成一个名为HelloWorld.class的字节码文件。

5.运行Java 程序：使用java命令运行编译后的Java 程
序：
java HelloWorld
如果一切正常，你应该在命令提示符中看到输出：Hello, World!。

这是一个简单的"Hello, World!" 程序，仅用于演示在命令提示符中编译
和运行Java 代码的基本步骤。

java常用代码（20条案例）1. 输出Hello World字符串public class Main {public static void main(String[] args) {// 使用System.out.println()方法输出字符串"Hello World"System.out.println("Hello World");}}2. 定义一个整型变量并进行赋值public class Main {public static void main(String[] args) {// 定义一个名为num的整型变量并将其赋值为10int num = 10;// 使用System.out.println()方法输出变量num的值System.out.println(num);}}3. 循环打印数字1到10public class Main {public static void main(String[] args) {// 使用for循环遍历数字1到10for (int i = 1; i <= 10; i++) {// 使用System.out.println()方法输出每个数字System.out.println(i);}}}4. 实现输入输出import java.util.Scanner;public class Main {public static void main(String[] args) {// 创建一个Scanner对象scanner，以便接受用户的输入Scanner scanner = new Scanner(System.in);// 使用scanner.nextLine()方法获取用户输入的字符串String input = scanner.nextLine();// 使用System.out.println()方法输出输入的内容System.out.println("输入的是：" + input);}}5. 实现条件分支public class Main {public static void main(String[] args) {// 定义一个整型变量num并将其赋值为10int num = 10;// 使用if语句判断num是否大于0，如果是，则输出"这个数是正数"，否则输出"这个数是负数"if (num > 0) {System.out.println("这个数是正数");} else {System.out.println("这个数是负数");}}}6. 使用数组存储数据public class Main {public static void main(String[] args) {// 定义一个整型数组nums，其中包含数字1到5int[] nums = new int[]{1, 2, 3, 4, 5};// 使用for循环遍历数组for (int i = 0; i < nums.length; i++) {// 使用System.out.println()方法输出每个数组元素的值System.out.println(nums[i]);}}}7. 打印字符串长度public class Main {public static void main(String[] args) {// 定义一个字符串变量str并将其赋值为"HelloWorld"String str = "Hello World";// 使用str.length()方法获取字符串的长度，并使用System.out.println()方法输出长度System.out.println(str.length());}}8. 字符串拼接public class Main {public static void main(String[] args) {// 定义两个字符串变量str1和str2，并分别赋值为"Hello"和"World"String str1 = "Hello";String str2 = "World";// 使用"+"号将两个字符串拼接成一个新字符串，并使用System.out.println()方法输出拼接后的结果System.out.println(str1 + " " + str2);}}9. 使用方法进行多次调用public class Main {public static void main(String[] args) {// 定义一个名为str的字符串变量并将其赋值为"Hello World"String str = "Hello World";// 调用printStr()方法，打印字符串变量str的值printStr(str);// 调用add()方法，计算两个整数的和并输出结果int result = add(1, 2);System.out.println(result);}// 定义一个静态方法printStr，用于打印字符串public static void printStr(String str) {System.out.println(str);}// 定义一个静态方法add，用于计算两个整数的和public static int add(int a, int b) {return a + b;}}10. 使用继承实现多态public class Main {public static void main(String[] args) {// 创建一个Animal对象animal，并调用move()方法Animal animal = new Animal();animal.move();// 创建一个Dog对象dog，并调用move()方法Dog dog = new Dog();dog.move();// 创建一个Animal对象animal2，但其实际指向一个Dog对象，同样调用move()方法Animal animal2 = new Dog();animal2.move();}}// 定义一个Animal类class Animal {public void move() {System.out.println("动物在移动");}}// 定义一个Dog类，继承自Animal，并重写了move()方法class Dog extends Animal {public void move() {System.out.println("狗在奔跑");}}11. 输入多个数并求和import java.util.Scanner;public class Main {public static void main(String[] args) {// 创建一个Scanner对象scanner，以便接受用户的输入Scanner scanner = new Scanner(System.in);// 定义一个整型变量sum并将其赋值为0int sum = 0;// 使用while循环持续获取用户输入的整数并计算总和，直到用户输入为0时结束循环while (true) {System.out.println("请输入一个整数（输入0退出）：");int num = scanner.nextInt();if (num == 0) {break;}sum += num;}// 使用System.out.println()方法输出总和System.out.println("所有输入的数的和为：" + sum);}}12. 判断一个年份是否为闰年import java.util.Scanner;public class Main {public static void main(String[] args) {// 创建一个Scanner对象scanner，以便接受用户的输入Scanner scanner = new Scanner(System.in);// 使用scanner.nextInt()方法获取用户输入的年份System.out.println("请输入一个年份：");int year = scanner.nextInt();// 使用if语句判断年份是否为闰年，如果是，则输出"是闰年"，否则输出"不是闰年"if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {System.out.println(year + "年是闰年");} else {System.out.println(year + "年不是闰年");}}}13. 使用递归实现斐波那契数列import java.util.Scanner;public class Main {public static void main(String[] args) {// 创建一个Scanner对象scanner，以便接受用户的输入Scanner scanner = new Scanner(System.in);// 使用scanner.nextInt()方法获取用户输入的正整数nSystem.out.println("请输入一个正整数：");int n = scanner.nextInt();// 使用for循环遍历斐波那契数列for (int i = 1; i <= n; i++) {System.out.print(fibonacci(i) + " ");}}// 定义一个静态方法fibonacci，使用递归计算斐波那契数列的第n项public static int fibonacci(int n) {if (n <= 2) {return 1;} else {return fibonacci(n - 1) + fibonacci(n - 2);}}}14. 输出九九乘法表public class Main {public static void main(String[] args) {// 使用两层for循环打印九九乘法表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();}}}15. 使用try-catch-finally处理异常import java.util.Scanner;public class Main {public static void main(String[] args) {// 创建一个Scanner对象scanner，以便接受用户的输入Scanner scanner = new Scanner(System.in);try {// 使用scanner.nextInt()方法获取用户输入的整数a和bSystem.out.println("请输入两个整数：");int a = scanner.nextInt();int b = scanner.nextInt();// 对a进行除以b的运算int result = a / b;// 使用System.out.println()方法输出结果System.out.println("计算结果为：" + result);} catch (ArithmeticException e) {// 如果除数为0，会抛出ArithmeticException异常，捕获异常并使用System.out.println()方法输出提示信息System.out.println("除数不能为0");} finally {// 使用System.out.println()方法输出提示信息System.out.println("程序结束");}}}16. 使用集合存储数据并遍历import java.util.ArrayList;import java.util.List;public class Main {public static void main(String[] args) {// 创建一个名为list的List集合，并添加多个字符串元素List<String> list = new ArrayList<>();list.add("Java");list.add("Python");list.add("C++");list.add("JavaScript");// 使用for循环遍历List集合并使用System.out.println()方法输出每个元素的值for (int i = 0; i < list.size(); i++) {System.out.println(list.get(i));}}}17. 使用Map存储数据并遍历import java.util.HashMap;import java.util.Map;public class Main {public static void main(String[] args) {// 创建一个名为map的Map对象，并添加多组键值对Map<Integer, String> map = new HashMap<>();map.put(1, "Java");map.put(2, "Python");map.put(3, "C++");map.put(4, "JavaScript");// 使用for-each循环遍历Map对象并使用System.out.println()方法输出每个键值对的值for (Map.Entry<Integer, String> entry :map.entrySet()) {System.out.println("key=" + entry.getKey() + ", value=" + entry.getValue());}}}18. 使用lambda表达式进行排序import java.util.ArrayList;import java.util.Collections;import parator;import java.util.List;public class Main {public static void main(String[] args) {// 创建一个名为list的List集合，并添加多个字符串元素List<String> list = new ArrayList<>();list.add("Java");list.add("Python");list.add("C++");list.add("JavaScript");// 使用lambda表达式定义Comparator接口的compare()方法，按照字符串长度进行排序Comparator<String> stringLengthComparator = (s1, s2) -> s1.length() - s2.length();// 使用Collections.sort()方法将List集合进行排序Collections.sort(list, stringLengthComparator);// 使用for-each循环遍历List集合并使用System.out.println()方法输出每个元素的值for (String str : list) {System.out.println(str);}}}19. 使用线程池执行任务import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class Main {public static void main(String[] args) {// 创建一个名为executor的线程池对象，其中包含2个线程ExecutorService executor =Executors.newFixedThreadPool(2);// 使用executor.execute()方法将多个Runnable任务加入线程池中进行执行executor.execute(new MyTask("任务1"));executor.execute(new MyTask("任务2"));executor.execute(new MyTask("任务3"));// 调用executor.shutdown()方法关闭线程池executor.shutdown();}}// 定义一个MyTask类，实现Runnable接口，用于代表一个任务class MyTask implements Runnable {private String name;public MyTask(String name) { = name;}@Overridepublic void run() {System.out.println("线程" +Thread.currentThread().getName() + "正在执行任务：" + name);try {Thread.sleep(2000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println("线程" +Thread.currentThread().getName() + "完成任务：" + name);}}20. 使用JavaFX创建图形用户界面import javafx.application.Application;import javafx.scene.Scene;import javafx.scene.control.Button;import yout.StackPane;import javafx.stage.Stage;public class Main extends Application {@Overridepublic void start(Stage primaryStage) throws Exception { // 创建一个Button对象btn，并设置按钮名称Button btn = new Button("点击我");// 创建一个StackPane对象pane，并将btn添加到pane中StackPane pane = new StackPane();pane.getChildren().add(btn);// 创建一个Scene对象scene，并将pane作为参数传入Scene scene = new Scene(pane, 200, 100);// 将scene设置为primaryStage的场景primaryStage.setScene(scene);// 将primaryStage的标题设置为"JavaFX窗口"primaryStage.setTitle("JavaFX窗口");// 调用primaryStage.show()方法显示窗口primaryStage.show();}public static void main(String[] args) { launch(args);}}。