利用UML类图设计Java应用程序详解.doc

利用UML类图设计Java应用程序详解（一）在第一部分中，我们实现了5个类。在本部分中，我们接着说明如何利用UML类图来设计余下的各个类。为减少篇幅，本部分着重讲解UML类图及应用，对Java实现代码不再详细描述。下载本文全部代码 六、CGPoint类CGPoint类说明了如何利用非抽象类扩展抽象类。CGPoint类是CGObject的子类，CGPoint类扩展了 CGObject类，CGPoint类没有再它所继承的变量中增加变量，它所声明的方法只有构造函数和要求它实现的抽象方法。其类图如下：Java实现代码为：/ CGPoint.javapublic class CGPoint extends CGObject / Method declarationspublic CGPoint(int x, int y,char ch) location = new Point(x,y);drawCharacter = ch;public CGPoint(int x, int y) this(x,y,+);public CGPoint(Point p) this(p.getX(),p.getY(),+);public CGPoint(Point p,char ch) this(p.getX(),p.getY(),ch);public void display(PrintCGrid grid) grid.setCharAt(drawCharacter,location);public void describe() System.out.print(CGPoint +String.valueOf(drawCharacter)+ );System.out.println(location.toString();七、CGBox类 CGBox类也扩展了CGObject类。CGBox类提供了在网格上显示矩形的附加变量。CGBox类的类图如下：相应的代码为：/ CGBox.javapublic class CGBox extends CGObject / Variable declarationsprotected Point lr; / Lower right corner of a box/ Method declarationspublic CGBox(Point ulCorner, Point lrCorner,char ch) location = ulCorner;lr = lrCorner;drawCharacter = ch;public CGBox(Point ulCorner, Point lrCorner) this(ulCorner,lrCorner,#);public void display(PrintCGrid grid) int width = lr.getX() - location.getX() + 1;int height = lr.getY() - location.getY() + 1;Point topRow = new Point(location);Point bottomRow = new Point(location.getX(),lr.getY(); for(int i=0; iheight;+i)grid.setCharAt(drawCharacter,leftCol);grid.setCharAt(drawCharacter,rightCol);leftCol = leftCol.add(0,1);rightCol = rightCol.add(0,1);public void describe() System.out.print(CGBox +String.valueOf(drawCharacter)+ );System.out.println(location.toString()+ +lr.toString(); 八、CGText类CGText类是CGObject中的第三个子类。其类图与代码分别如下：相应的代码为：/ CGText.javapublic class CGText extends CGObject / Variable declarationsString text;/ Method declarationspublic CGText(Point p,String s) location = p;drawCharacter = ;text = s;public void display(PrintCGrid grid) Point p = new Point(location);for(int i=0;i以下是CGObject类、CGPoint类、CGBox类、CGText类及Point类之间的相互关系。注意CGObject类是抽象类，其类名用斜体表示。九、KeyboardInput类 KeyboardInput类扩展了Java API的DataInputStream类，用来提供获取用户键盘输入的一系列常用的简单方法。其类图设计为：代码为：import java.lang.System;import java.io.DataInputStream;import java.io.InputStream;import java.io.IOException;/KeyboardInput.javapublic class KeyboardInput extends DataInputStream public KeyboardInput(InputStream inStream) super(inStream);public char getChar() throws IOException String line = readLine();if(line.length()=0) return ;return line.charAt(0);public String getText() throws IOException String line = readLine();return line;public int getInt() throws IOException String line = readLine();Integer i = new Integer(line);return Value();public Point getPoint() throws IOException System.out.print( x-coordinate: );System.out.flush();int x = getInt();System.out.print( y-coordinate: );System.out.flush();int y = getInt();return new Point(x,y);十、CDrawApp类主程序由CDrawApp类所构成。它包含main()方法，main()方法建立类CDraw的对象，然后调用该对象的run()方法。其中CDraw类属于内部类，当然你也可以将它单独作为一个类文件编辑、编译，其效果是一样的。其中类与内部类之间的关系，用关联关系来表达，外部类用一个十字交叉圆圈表示，箭头指向内部类。如下图所示：其代码实现为：import java.io.DataInputStream;import java.io.IOException;/CDrawApp.javaclass CDrawApp public static void main(String args) throws IOException CDraw program = new CDraw();program.run();class CDraw / Variable declarationsstatic KeyboardInput kbd = new KeyboardInput(System.in); BorderedPrintCGrid grid;/ Method declarationsCDraw() grid = new BorderedPrintCGrid();void run() throws IOException boolean finished = false;do char command = getCommand();switch(command)case P:addPoint();System.out.println();break;case B:addBox();System.out.println();break;case T:addText();System.out.println();break;case U:grid.deleteLastObject();System.out.println();break;case C:grid.clearGrid();System.out.println();break;case S:grid.show();break;case X:finished = true;default:System.out.println(); while (!finished);char getCommand() throws IOException System.out.println(CDrawApp P - Add a Point U - Undo Last Add);System.out.print (Main Menu B - Add a Box C - Clear Grid);System.out.println( X - Exit CDrawApp); System.out.print ( T - Add Text S - Show Grid );System.out.print ( Enter command: ); System.out.flush();return Character.toUpperCase(kbd.getChar();void addPoint() throws IOException System.out.println(Add Point Menu);System.out.println( Location:);Point p = kbd.getPoint();System.out.print( Character: );System.out.flush();char ch = kbd.getChar();if(ch= ) ch = +;CGPoint cgp = new CGPoint(p,ch);cgp.addToGrid(grid);void addBox() throws IOException System.out.println(Add Box Menu);System.out.println( Upper Left Corner:); Point ul = kbd.getPoint();System.out.println( Lower Right Corner:); Point lr = kbd.getPoint();System.out.print( Character: );System.out.flush();char ch = kbd.getChar();if(ch= ) ch = #;CGBox box = new CGBox(ul,lr,ch);box.addToGrid(grid);void addText() throws IOException System.out.println(Add Text Menu);System.out.println( Location:);Point p = kbd.getPoint();System.out.print( Text: );System.out.flush();String text = kbd.getText();CGText cgt = new CGText(p,text);cgt.addToGrid(grid);主程序CDrawApp类与相应类之间的关系为：按照本文次序分别编译以上的10个大类，然后运行主程序CdrawApp即可。在程序运行时请注意：当选择增加点、框或者文本串后，选择Show Grid才能出现网格，并显示结果。本文通过一个具体的程序开发过程，详细说明了如何使用UML类图来设计Java应用程序，使得程序开发可视化，文档标准化，便于相互协作与管理，是Java应用程序开发的方向 。利用UML类图设计Java应用程序详解（二）在第一部分中，我们实现了5个类。在本部分中，我们接着说明如何利用UML类图来设计余下的各个类。为减少篇幅，本部分着重讲解UML类图及应用，对Java实现代码不再详细描述。下载本文全部代码 六、CGPoint类CGPoint类说明了如何利用非抽象类扩展抽象类。CGPoint类是CGObject的子类，CGPoint类扩展了 CGObject类，CGPoint类没有再它所继承的变量中增加变量，它所声明的方法只有构造函数和要求它实现的抽象方法。其类图如下：Java实现代码为：/ CGPoint.javapublic class CGPoint extends CGObject / Method declarationspublic CGPoint(int x, int y,char ch) location = new Point(x,y);drawCharacter = ch;public CGPoint(int x, int y) this(x,y,+);public CGPoint(Point p) this(p.getX(),p.getY(),+);public CGPoint(Point p,char ch) this(p.getX(),p.getY(),ch);public void display(PrintCGrid grid) grid.setCharAt(drawCharacter,location);public void describe() System.out.print(CGPoint +String.valueOf(drawCharacter)+ );System.out.println(location.toString();七、CGBox类 CGBox类也扩展了CGObject类。CGBox类提供了在网格上显示矩形的附加变量。CGBox类的类图如下：相应的代码为：/ CGBox.javapublic class CGBox extends CGObject / Variable declarationsprotected Point lr; / Lower right corner of a box/ Method declarationspublic CGBox(Point ulCorner, Point lrCorner,char ch) location = ulCorner;lr = lrCorner;drawCharacter = ch;public CGBox(Point ulCorner, Point lrCorner) this(ulCorner,lrCorner,#);public void display(PrintCGrid grid) int width = lr.getX() - location.getX() + 1;int height = lr.getY() - location.getY() + 1;Point topRow = new Point(location);Point bottomRow = new Point(location.getX(),lr.getY(); for(int i=0; iheight;+i)grid.setCharAt(drawCharacter,leftCol);grid.setCharAt(drawCharacter,rightCol);leftCol = leftCol.add(0,1);rightCol = rightCol.add(0,1);public void describe() System.out.print(CGBox +String.valueOf(drawCharacter)+ );System.out.println(location.toString()+ +lr.toString(); 八、CGText类CGText类是CGObject中的第三个子类。其类图与代码分别如下：/ CGText.javapublic class CGText extends CGObject / Variable declarationsString text;/ Method declarationspublic CGText(Point p,String s) location = p;drawCharacter = ;text = s;public void display(PrintCGrid grid) Point p = new Point(location);for(int i=0;i= limit) noOfWidths+;return noOfWidths * widthSurface;public double getTotalPrice(Surface aSurface) return getNoOfMeters(aSurface) * price;以上三个类之间的类图关系可以表示为如下图： 以下我们来详细分析类FlooringClient是如何发送消息给其它类，而实现方法的调用过程。并如何用UML序列图来描述这一序列过程。一、getNoOfMeters()方法让我们来看看是如何发送消息getNoOfMeters()的。对象Flooring要计算出需要多少米的材料才能贴满一定面积的表面，就需要对象Flooring与对象Surface之间相互作用。FlooringClient通过发送消息给getNoOfMeters()对象Flooring，在getNoOfMeters()方法的代码中，Flooring又发送消息给Surface而得到length和width。以上过程用UML序列图描述如下图：UML序列图描述了消息是如何在给对象间发送的。下面我们来详细解释以上UML序列图的含义，通过上述序列图，我们得知有以下8个过程：1. FlooringClient新建一个对象theSurface2. FlooringClient新建一个对象theFlooring3. FlooringClient发送一个消息给对象theFlooring，并以theSurface为变量4. theFlooring发送一个消息getLength()给theSurface5. theSurface发送一个回应给theFlooring6. theFlooring发送一个消息getWidth ()给theSurface7. theSurface发送一个回应给theFlooring8. theFlooring发送一个回应给FlooringClient二、getTotalPrice()方法 在FlooringClient程序中，我们有如下语句：doubl