Java程序设计实验报告-计算器.doc

java程序设计实验报告题 目 计算器 姓 名 学 号 学 院 软件学院 专 业 软件工程 年 级 2009 级 指导教师 2010年 4 月 9 日一、实验目的1、 熟练掌握java面向对象编程。2、 选择合适的数据结构实现需求。3、 熟练使用各种控制结构。4、 掌握gui组件、事件处理技术。二、实验任务1、 设计一个简易的计算器，可以进行四则运算：加、减、乘、除等（限于十进制下）程序要求：（1）应具有相应的界面，可参考下图进行设计： 图示1 图示2（2）操作符号定为：“+”，“-”，“*”，“/”，“(”,“)”等。（按国际惯例设计）（3）用户通过点击面板中的各种组件输入的表达式，应在上方文本框中显示。（4）当用户点击“=”时，文本框中之前的内容应清空，直接显示表达式运算结果。例如：输入表达式“3+2*（8-5）”之后按“=”，显示结果“9”。（5）具有菜单栏，内有相应的编辑“复制”、“粘贴”等菜单，提供相应的功能。（6）以上部分为必须完成的内容。2、选作功能，可参考windows系统附带计算器： （1）具有相应的科学计算功能。例如“图示2”中的各种科学计算功能。三、开发工具与平台1.开发工具：eclipse默认是一个和jbuilder类似的java开发工具，但它不仅仅只 是java开发工具，只要装上相应的插件，eclipse也可作为其它语言的开发工具。如c/c+插件(cdt)。2.开发平台：jdk1.5四、设计思路1.界面设计 （1）制作一个简单的面板jframe，在其上面添加构造界面所需的各种组件其构造方法为：calculate()super();this.setbounds(10, 10, 300, 250);this.setdefaultcloseoperation(jframe.exit_on_close);this.setresizable(false);this.settitle(计算器);init();/创建菜单及各种组件（如按钮，文本框等）getcontentpane().setlayout(new borderlayout(3,3);getcontentpane().add(panelcenter,borderlayout.center);getcontentpane().add(panelnorth,borderlayout.north);（2）实现构造菜单及文本框等组件的函数init(),如下实现：public void init()/菜单项的构造形成； editor.add(copy);editor.addseparator();editor.add(paste); editor.setmnemonic(e);look.setmnemonic(v);help.setmnemonic(h); copy.setaccelerator(keystroke.getkeystroke(keyevent.vk_c,inputevent.ctrl_mask); paste.setaccelerator(keystroke.getkeystroke(keyevent.vk_p,inputevent.ctrl_mask); help.add(about); bar.add(editor);bar.add(look);bar.add(help); setjmenubar(bar);/将菜单添加到jframe； /* 接下来是文本或结果显示区及backspace、功能键（ce、c）和的添加，采用 gridbaglayout布局方式，将它们放在北部panelnorth面板。 其次，是数字键及其他功能键的的使用，我这里采用的是网格布局，setlayout(new gridlayout(4,6,5,5);将它们放在主面板中心区域。 这里给出网格包布布局的两个重要方法，由于代码段较长，故将其他的代码放在后面附录；private void makeshow(gridbaglayout gridbag,gridbagconstraints constraints, component component) gridbag.setconstraints(component, constraints);/ 网格包布布局； panelnorth2.add(component);private void addbutton(gridbaglayout gridbag,/网格包布布局重要方法；gridbagconstraints constraints, component component) gridbag.setconstraints(component, constraints); panelnorth1.add(component);总体界面如下：2.逻辑设计 为了能够得到我们想要的操作，比如让那些数字参与运算，做什么运算等等，我们就需要为每个按钮添加响应事件，通过响应事件来完成我们预期的结果。以下我们来分析下重要的事件是如何响应的：.string str = e.getactioncommand();/ todo auto-generated method stubif(str.equals(backspace)/点击 backspacehanderbackspace();else if(str.equals(ce)/点击了ce的功能是清除当前显示的数值bool = false;show.settext(0);else if(str.equals(c)/点击了c的功能是清零copytext=;div = 0.0;calculateresult =;bool = false;show.settext(0);else if(str.equals(mc)/mc清楚存储器内容handermc();else if(str.equals(mr)/mr将存于存储器的值显示在文本框中handermr();else if(str.equals(ms)/ms将显示框得文字存于存储器handerms();else if(str.equals(m+)/m+将显示框的数与存储器中的数相加并进行存储handerm();else if(0123456789.indexof(str)=0)/按下的是数字键或者小数点正负号handercenter(str);else if(str.equals(%)/将当前显示框里的数字用百分比表示（ x/100）string current = show.gettext();double a = 0;if(!current.isempty() a = double.parsedouble(current); double result =(double) a/100; string s4 = result.tostring(); if(!isint(s4) show.settext(s4);else show.settext(s4.substring(0,s4.indexof(.); bool = true; else handeroperation(str);/响应的是运算符；处理运算符操作3. 程序测试 程序测试过程中无较大bug，基本上轻松搞定。五、实验总结 这是我第一次正式的java程序设计实验，感觉能够把学到的东西用到实际中是件非常有趣的事，更重要的是让我们真正明白了学贵致用的道理。 由于时间有限，本程序未能做到科学计算器，同时在这里也感谢老师的指导和同学的帮助。6、 附录public class calculate extends jframe implements actionlistener /* * param args */private jmenubar bar = new jmenubar();private jmenu editor =new jmenu(编辑(e);private jmenuitem copy =new jmenuitem(复制);private jmenuitem paste =new jmenuitem(粘贴);private jmenu look = new jmenu(查看(v);private jmenu help = new jmenu(帮助(h);private jmenuitem about = new jmenuitem(关于);private string copytext ;private jpanel panelwest= new jpanel();private jpanel panelcenter = new jpanel();/放number键private jpanel panelnorth = new jpanel();/放功能键1与文本框private jpanel panelnorth1 = new jpanel();private jpanel panelnorth2 = new jpanel();/放显示框private jpanel paneleast = new jpanel();/放运算键；private string strnorth = new stringbackspace,ce,c;/功能键1private string strcenter = new string7,8,9,4,5,6,1,2,3,0,+/-,.;private string streast = new string/,sqrt,*,%,-,1/x,+,=;private stringstrwest = new stringmc,mr,ms,m+;private jbutton buttoncenter = new jbuttonstrcenter.length;private jbutton buttoneast= new jbuttonstreast.length;private jbutton buttonnorth = new jbuttonstrnorth.length;private jbutton buttonwest = new jbuttonstrwest.length;private string ch=new string();/保存当前运算符private double div;/保存中间运算数private string save = new string();/保存存储器中的数值private string calculateresult= new string() ;/保存运算结果private boolean bool = false;/当前结果是否为运算结果private jtextfield show = new jtextfield(0,24);/输出显示private jtextfield label;private gridbaglayout gridbag = new gridbaglayout();/网格包布布局；private gridbagconstraints constraints = new gridbagconstraints();calculate()super();this.setbounds(10, 10, 300, 250);this.setdefaultcloseoperation(jframe.exit_on_close);this.setresizable(false);this.settitle(计算器);init();getcontentpane().setlayout(new borderlayout(3,3);getcontentpane().add(panelcenter,borderlayout.center);getcontentpane().add(panelnorth,borderlayout.north);public void init() editor.add(copy);editor.addseparator();editor.add(paste); editor.setmnemonic(e);look.setmnemonic(v);help.setmnemonic(h); copy.setaccelerator(keystroke.getkeystroke(keyevent.vk_c,inputevent.ctrl_mask); paste.setaccelerator(keystroke.getkeystroke(keyevent.vk_p,inputevent.ctrl_mask); help.add(about); bar.add(editor);bar.add(look);bar.add(help); setjmenubar(bar); copy.addactionlistener(this); paste.addactionlistener(this); about.addactionlistener(this); panelnorth1.setlayout(gridbag);/ panelnorth2.setlayout(gridbag); show.sethorizontalalignment(jtextfield.right);/右对齐; show.seteditable(false); panelnorth.setlayout(new borderlayout(); panelnorth.add(show,borderlayout.north); show.setborder(new bevelborder(bevelborder.lowered);/让显示框凹陷下去 show.setbackground(color.white); /网格包布布局； constraints.gridx = 0; constraints.gridy = 0; constraints.fill = gridbagconstraints.none; constraints.anchor = gridbagconstraints.center; makeshow(gridbag,constraints,show); /* /设置箱式布局间隔 (另一种布局方式) * / box.add(label); for(int i = 0;istrnorth.length;+i) buttonnorthi = new jbutton(strnorthi); box.add(box.createhorizontalstrut(10); box.add(buttonnorthi); buttonnorthi.addactionlistener(this); buttonnorthi.setforeground(color.red); */ label = new jtextfield(2); label.seteditable(false); label.setborder(new bevelborder(bevelborder.lowered);/让文本框凹陷下去； constraints.gridx = 0; constraints.gridy = 0; constraints.fill = gridbagconstraints.none; constraints.insets = new insets(10,5,10,10); addbutton(gridbag,constraints,label); for(int j = 0;jstrnorth.length;+j) buttonnorthj = new jbutton(strnorthj); buttonnorthj.addactionlistener(this); buttonnorthj.setforeground(color.red); constraints.gridx =j+1 ; constraints.gridy = 0; addbutton(gridbag,constraints,buttonnorthj); panelnorth.add(panelnorth1,borderlayout.center); panelnorth.add(panelnorth2,borderlayout.north); panelcenter.setlayout(new gridlayout(4,6,5,5); for(int i =0;istrwest.length;+i) buttonwesti = new jbutton(strwesti); buttonwesti.setborder(new bevelborder(bevelborder.raised); buttonwesti.setforeground(color.red); buttonwesti.addactionlistener(this); for(int i =0;istrcenter.length;+i) buttoncenteri = new jbutton(strcenteri); buttoncenteri.setborder(new bevelborder(bevelborder.raised); buttoncenteri.setforeground(color.blue); buttoncenteri.addactionlistener(this); for(int i =0;istreast.length;+i) buttoneasti = new jbutton(streasti); buttoneasti.setborder(new bevelborder(bevelborder.raised); buttoneasti.addactionlistener(this); if(i%2=0|(i=7) buttoneasti.setforeground(color.red); else buttoneasti.setforeground(color.blue); int w =0,e = 0, c = 0; for(int i = 0;i24;) if(i%6=0) buttonwestw.setborder(new lineborder(color.gray); panelcenter.add(buttonwestw); +i; +w; else for(int j = 0;j3;+j) buttoncenterc.setborder(new lineborder(color.gray); panelcenter.add(buttoncenterc); +i; +c; for(int j = 0;j=0)/按下的是数字键或者小数点正负号handercenter(str);else if(str.equals(%)/将当前显示框里的数字用百分比表示（ x/100）string current = show.gettext();double a = 0;if(!current.isempty() a = double.parsedouble(current); double result =(double) a/100; string s4 = result.tostring(); if(!isint(s4) show.settext(s4);else show.settext(s4.substring(0,s4.indexof(.); bool = true; else handeroperation(str);private void handermc() save = ;/ todo auto-generated method stublabel.settext();private void handermr() if(!save.isempty() if(!isint(save) show.settext(save); else show.settext(save.substring(0,save.indexof(.); private void handerms() save = show.gettext();/ todo auto-generated method stubprivate void handerm() string str = show.gettext();/ todo auto-generated method stubdouble s=0,v=0;if(!str.isempty()&!save.isempty() s= double.parsedouble(str); v = double.parsedouble(save);save = string.valueof(s+v);label.settext(m);private void handercenter(string str) string result = show.gettext();if(str.equals(.)if(!(result.indexof(.)=0)/判断是否已存在小数点if(bool)show.settext();result=;result+=str;show.settext(result);bool = false;string num = result;if(*-+/.indexof(ch)=0) handerresult(ch,num); else if(result.equals(0)result=str;show.settext(result);bool = false;string num = result;if(*-+/.indexof(ch)=0)handerresult(ch,num); else if(bool)show.settext();/文本框不为0.既有数字或者0和小数点result = ;result+=str;show.settext(result);bool = false;string num = result;/保存if(*-+/.indexof(ch)=0) handerresult(ch,num); private void handeroperation(string str) string result = show.gettext();if(str.equals(+/-)/处理正负号 if(result.indexof(-)=0) stringbuffer e = new stringbuffer(result); e.deletecharat(0); show.settext(e.tostring(); string num = e.tostring(); if(*-+/.indexof(ch)=0) handerresult(ch,num); else stringbuffer e = new stringbuffer(result); e.insert(0, -); show.settext(e.tostring(); string num = e.tostring(); if(*-+/.indexof(ch)=0) handerresult(ch,num); else if(str.equals(sqrt)/平方根功能if(!(result.indexof(-)=0)double operate=0;if(!result.isempty() operate =double.parsedouble(result); double reult = math.sqrt(operate); double a = reult; string s =a.tostring(); if(!isint(s) show.settext(s); else show.settext(s.substring(0,s.indexof(.); bool = true; if(*-+/.indexof(ch)=0) handerresult(ch,s); else show.settext(函数输入无效);bool= true;else if(str.equals(/)/除法运算；string show2 = show.gettext();show.settext();ch=/;double operate = 0;if(!show2.isempty()operate = double.parsedouble(show2); div = (double)operate;/保存被除数；else if(str.equals(*)string show2 = show.gettext();show.settext();ch=*;/保存当前运算符double operate = 0;if(!show2.isempty() operate = double.parsedouble(show2);div = (double)operate;else if(str.equals(-)string show2 = show.gettext();show.settext();ch=-;double operate =0;if(!show2.isempty() operate= double.parsedouble(show2);div = (double)operate;else if(str.equals(+)string show2 = show.gettext();show.settext();ch=+;double operate = 0;if(!show2.isempty() operate = double.parsedouble(show2); div = (double)operate;/保存加数else if(str.equals(1/x)/求倒string show2 = show.gettext();if(!show2.equals(0)double operate = 0;if(!show2.isempty() operate = double.parsedouble(show2);double resultreverse = (1/operate);double resultreversedouble = resultreverse;show.settext(resultreversedouble.tostring();bool = true;else show.settext(除数不能为零。);bool = true;else if(str.equals(=)show.settext(calculateresult);bool = true;private boolean isint(string s) if(s.indexof(.)0)for(int i =(s.length()-1);is.indexof(.);-i) if(!(s.charat(i)=0) return false;return true;private void handerresult(string ch,string num) /处理运算结果并保存； char swt = 0 ;if(!ch.equals() swt = ch.charat(0);/将s