JAVA小應用程序Applet設計(計算器)實驗報告(附代碼)

小應用程序Applet設計一、課題內容和要求內容：設計和編寫一個可以用鼠標操作的Applet小應用程序和相應的HTML頁面，觀察Applet的執(zhí)行過程，測試程序鼠標用戶交互操作的效果。要求：要求學生能在學習和理解課堂學習內容中JAVA小應用程序的根底上，通過實驗，培養(yǎng)學生將JAVA小應用程序相關知識點〔包括JAVAApplet和低級事件處理模型〕有機結合，設計基于WEB瀏覽器的小應用程序的能力。二、設計思路分析classApw個JavaApple計算器的主類publicvoidinit()完成初始化appletpublicbooleanaction(詼現事件處理的方法publicvoiddoOperator()運算及運算結果輸出操作publicvoiddoForeScreen微字和小數點輸出到文本框操作publicvoiddoClear(X青空操作三、概要設計publicclassAppextendsApplet{TextFieldtfAnswer;Buttonb0,b1,b2,b3,b4,b5,b6,b7,b8,b9;ButtonbPoint,bEqual,bPlus,bMinus,bClear,bMulti,bDivision;StringOperatorCurrent,OperatorPre;StringForeScreen,BackScreen;booleanisFloat=false;

publicvoidinit();publicbooleanaction(Evente,Objecto);publicvoiddoOperator()publicvoiddoForeScreen(Strings);publicvoiddoClear();事件處理:hCitarj清除技軌走肝清除操作lr((e.tiir^et=hMuhl)|| =h i*,tarnrf『hPM。IhGtar^er=lAlirim)g劇Ld=bEquM))加減期蟠于按鈕獲取運算操作符并進i；運算操作卜") 沒有幣源輸入數字/作為上?道值新輸人奴字算符一項證硒入隹續(xù)的同考算存進行■■運算提作M1也fag==bg||hCitarj清除技軌走肝清除操作lr((e.tiir^et=hMuhl)|| =h i*,tarnrf『hPM。IhGtar^er=lAlirim)g劇Ld=bEquM))加減期蟠于按鈕獲取運算操作符并進i；運算操作卜") 沒有幣源輸入數字/作為上?道值新輸人奴字算符一項證硒入隹續(xù)的同考算存進行■■運算提作if"上的啡以=bP曲n。&&if"上的啡以=bP曲n。&&：Fi)rcScrx^n.eiMit漸儀”/'W保正屈數不含小費點的情況下張瓶小數點力在控制臺和文本相?出If!=iMMnh裁取數字桌來有崎A數懶佩IfiFortScreenJtquste(',1T)桌來有崎A數懶佩運算及運算結果輸出if(OperttotPre,M|ual5(,m))上一運算符沒杓則直接啕出else上…運算符存在則運算后輸圉 SZ BaekScrwn■ForeStrven;FureScreen-n,1：dAnswur.sctItBackSereun)：Repaint0;冬力人的數掂轉入EhskS4mti并清空，用HuckScrMn輸出它SZdFort=(notPoubIc(FnreScr^enIlkatue():dBack=(newDouble<BickScrt*?n))Lduul>LeValih*Q^KorcScreen=***;Bnck'icrren=rfA^wer，2iirTev?0:運算結果轉入BMkScr"D井清空.BackScrccn輸出它，再對各運算符作運算操作四、詳細設計Java代碼：importjava.awt.*;importjava.applet.*;publicclassAppextendsApplet{TextFieldtfAnswer;//定義變量Buttonb0,b1,b2,b3,b4,b5,b6,b7,b8,b9;ButtonbPoint,bEqual,bPlus,bMinus,bClear,bMulti,bDivision;StringOperatorCurrent,OperatorPre;StringForeScreen,BackScreen;booleanisFloat=false;publicvoidinit(){//初始化OperatorCurrent=newString("");OperatorPre=newString("");ForeScreen=newString("0");//保證輸入字符串不為空防止計算錯誤BackScreen=newString("");setBackground(Color.gray);setLayout(null);//設為空布局便于自定義組件位置tfAnswer=newTextField();//設置文本框樣式tfAnswer.setBounds(20,20,175,40);tfAnswer.setFont(newFont(BackScreen,Font.BOLD,28));add(tfAnswer);tfAnswer.setText(ForeScreen);bClear=newButton("C");//設置按鈕樣式bClear.setBounds(20,70,40,40);add(bClear);bDivision=newButton("/");bDivision.setBackground(Color.green);bDivision.setBounds(65,70,40,40);add(bDivision);bMulti=newButton("*");bMulti.setBackground(Color.green);bMulti.setBounds(110,70,40,40);add(bMulti);bMinus=newButton("-");bMinus.setBackground(Color.green);bMinus.setBounds(155,70,40,40);add(bMinus);b7=newButton("7");b7.setBounds(20,115,40,40);b7.setBackground(Color.orange);add(b7);b8=newButton("8");b8.setBackground(Color.orange);b8.setBounds(65,115,40,40);add(b8);b9=newButton("9");b9.setBackground(Color.orange);b9.setBounds(110,115,40,40);add(b9);bPlus=newButton("+");bPlus.setBackground(Color.green);bPlus.setBounds(155,115,40,85);add(bPlus);b4=newButton("4");b4.setBackground(Color.orange);b4.setBounds(20,160,40,40);add(b4);b5=newButton("5");b5.setBackground(Color.orange);b5.setBounds(65,160,40,40);add(b5);b6=newButton("6");b6.setBackground(Color.orange);b6.setBounds(110,160,40,40);add(b6);b1=newButton("1");b1.setBackground(Color.orange);b1.setBounds(20,205,40,40);add(b1);b2=newButton("2");b2.setBackground(Color.orange);b2.setBounds(65,205,40,40);add(b2);b3=newButton("3");b3.setBackground(Color.orange);b3.setBounds(110,205,40,40);add(b3);bEqual=newButton("=");bEqual.setBackground(Color.green);bEqual.setBounds(155,205,40,85);add(bEqual);b0=newButton("0");b0.setBackground(Color.orange);b0.setBounds(20,250,85,40);add(b0);bPoint=newButton(".");bPoint.setBackground(Color.orange);bPoint.setBounds(110,250,40,40);add(bPoint);}publicbooleanaction(Evente,Objecto){//實現事件處理的方法Strings=newString("");if((e.target==b0)||(e.target==b1)||(e.target==b2)||(e.target==b3)||(e.target==b4)||(e.target==b5)||(e.target==b6)||(e.target==b7)||(e.target==b8)||(e.target==b9)){//獲取數字按鈕數據并在控制臺和文本框輸出if(e.target!=bPoint){//獲取數字s=(String)o;doForeScreen(s);}}if((e.target==bPoint)&&!ForeScreen.contains(".")){//保證原數不含小數點的情況下獲取小數點并在控制臺和文本框輸出s=(String)o;if(ForeScreen.equals(""))//原來沒有輸入數據那么用0.{doForeScreen("0.");}else//原來有輸入數據那么用.{doForeScreen(s);}}if(e.target==bClear){//去除按鈕進展去除操作doClear();}if((e.target==bMulti)||(e.target==bDivision)||(e.target==bPlus)||(e.target==bMinus)||(e.target==bEqual)){//加減乘除等于按鈕獲取運算操作符并進展運算操作if(ForeScreen!=""){//重新輸入數字進展運算操作OperatorCurrent=((String)o);doOperator();}else{//沒有重新輸入數字那么作為上一運算符---＞保證不輸入連續(xù)的同一運算符OperatorPre=((String)o);}}returntrue;}publicvoiddoOperator(){//運算及運算結果輸出操作doubledFore,dBack;Doubled;if(OperatorPre.equals("")){//上一運算符沒有那么直接輸出BackScreen=ForeScreen;//輸入的數據轉入后臺并清空，用后臺輸出它ForeScreen="";tfAnswer.setText(BackScreen);repaint();}else{//上一運算符存在那么運算后輸出dFore=(newDouble(ForeScreen)).doubleValue();dBack=(newDouble(BackScreen)).doubleValue();ForeScreen="";//運算結果轉入后臺并清空，用后臺輸出它BackScreen=tfAnswer.getText();if(OperatorPre.equals("+")){d=newDouble((dBack+dFore));BackScreen=d.toString();}if(OperatorPre.equals("-")){d=newDouble((dBack-dFore));BackScreen=d.toString();}if(OperatorPre.equals("*")){d=newDouble((dBack*dFore));BackScreen=d.toString();}if(OperatorPre.equals("/")){d=newDouble((dBack/dFore));BackScreen=d.toString();}tfAnswer.setText(BackScreen);repaint();}OperatorPre=OperatorCurrent;//現運算符變上一運算符repaint();}publicvoiddoForeScreen(Strings){//數字和小數點輸出到文本框操作ForeScreen+=s;if(ForeScreen.length()>1&&ForeScreen.startsWith("0")&&!ForeScreen.contains("."))//以0開頭的長度大于一的非小數去掉開頭的0ForeScreen=ForeScreen.substring(1);tfAnswer.setText(ForeScreen);repaint();}publicvoiddoClear(){//清空操作OperatorCurrent="";OperatorPre="";ForeScreen="0";B